To see the other types of publications on this topic, follow the link: Otoliti.
Dissertations / Theses on the topic 'Otoliti'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Otoliti.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Stagioni, Marco <1974>. "Identificazione di possibili unita' di stock di Anguilla anguilla mediante analisi microchimica e morfometrica degli otoliti." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7015/1/Stagioni_Marco_tesi.pdf.
Full textAbstract:
L’anguilla europea, è una specie eurialina catadroma con un complesso ciclo biologico: l’area di riproduzione, unica, si trova molto distante da quella di distribuzione. La specie necessita di una gestione dello stock a fini conservazionistici. Il problema è europeo: lo stock è unico, distribuito in Europa e nell’Africa settentrionale, si riproduce in Atlantico ed è panmittico. C’è preoccupazione per il declino del reclutamento e delle catture di adulti. Lo scopo del progetto è di individuare possibili unità di stock nella penisola italiana. La ricerca è basata sullo studio degli otoliti mediante analisi morfometrica e microchimica. I contorni degli otoliti sono sottoposti ad analisi ellittica di Fourier per individuare eventuali gruppi. Gli otoliti sono stati levigati per effettuare: letture d’età, indagini microstrutturali al SEM delle fasi larvali, analisi microchimiche LA-ICP-MS del nucleo, studiarne l’origine e valutare l’ambiente di sviluppo. Le indagini morfometriche mostrano evidenti pattern ontogenetici, ma non legati ocorrelati alla località, sesso o anno di nascita. Le indagini microstrutturali hanno evidenziano l’alto contenuto organico nucleare, un pattern comune di crescita ed eventi chiave delle fasi larvali, con una media di 212 anelli giornalieri. La microchimica rivela che le larve si sviluppano in acque salate fino alla metamorfosi, poi migrano verso acque meno salate. Le analisi su campioni nati nello stesso anno, evidenziano due gruppi: individui di rimonta naturale e individui di ripopolamento. I profili nucleo bordo evidenziano la permanenza a salinità intermedie degli adulti. L’attività di ricerca si è dimostrata proficua dal punto di vista tecnico con la messa a punto di protocolli innovativi e con forti ricadute sulla riduzione dei tempi e costi d’analisi. Il debole segnale di possibili unità di stock andrà verificato in futuro mediante analisi più dettagliate discriminando meglio la storia di ogni singolo individuo.The European eel is euryhaline catadromous with a complex life cycle: spawning area, unique, is far from that of distribution. The species needs a stock management and its conservation. The problem is European: the stock is unique, distributed in Europe and North Africa, spawning in Atlantic Sea and is panmictic. There is concern about the decline of recruitment and catches of adults. The purpose of the project is to identify possible units of stock in the Italian peninsula. The research is based on the study of otoliths by morphometric and microchemical analyses . The otoliths contours are analyzed by elliptic Fourier function to discover any groups. Otoliths were polished to make: ageing, SEM microstructural investigations of larval stages, LA-ICP-MS microchemical analysis of the core to study the origin and along a transect core to edge to evaluate the development environment. Morphometric investigations show obvious ontogenetic pattern, but no location, gender or year of birth correlation. The microstructural investigations showed high organic content in the core, a common pattern of growth and key events of the larval stages, with an average of 212 daily rings. The microchemical reveals that the larvae develop into salt water until metamorphosis, then migrate to waters less salty. Analyses of samples born in the same year, showed two groups: wild and restocked. The profiles confirm that the adult stay in brackishwater. The development of innovative protocols and improved technics have guaranteed a strong reduction of time and cost of analysis. The weak signal of possible stock units will be further tested through more detailed analysis discriminating about the life history of each individual.
2
Stagioni, Marco <1974>. "Identificazione di possibili unita' di stock di Anguilla anguilla mediante analisi microchimica e morfometrica degli otoliti." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7015/.
Full textAbstract:
L’anguilla europea, è una specie eurialina catadroma con un complesso ciclo biologico: l’area di riproduzione, unica, si trova molto distante da quella di distribuzione. La specie necessita di una gestione dello stock a fini conservazionistici. Il problema è europeo: lo stock è unico, distribuito in Europa e nell’Africa settentrionale, si riproduce in Atlantico ed è panmittico. C’è preoccupazione per il declino del reclutamento e delle catture di adulti. Lo scopo del progetto è di individuare possibili unità di stock nella penisola italiana. La ricerca è basata sullo studio degli otoliti mediante analisi morfometrica e microchimica. I contorni degli otoliti sono sottoposti ad analisi ellittica di Fourier per individuare eventuali gruppi. Gli otoliti sono stati levigati per effettuare: letture d’età, indagini microstrutturali al SEM delle fasi larvali, analisi microchimiche LA-ICP-MS del nucleo, studiarne l’origine e valutare l’ambiente di sviluppo. Le indagini morfometriche mostrano evidenti pattern ontogenetici, ma non legati ocorrelati alla località, sesso o anno di nascita. Le indagini microstrutturali hanno evidenziano l’alto contenuto organico nucleare, un pattern comune di crescita ed eventi chiave delle fasi larvali, con una media di 212 anelli giornalieri. La microchimica rivela che le larve si sviluppano in acque salate fino alla metamorfosi, poi migrano verso acque meno salate. Le analisi su campioni nati nello stesso anno, evidenziano due gruppi: individui di rimonta naturale e individui di ripopolamento. I profili nucleo bordo evidenziano la permanenza a salinità intermedie degli adulti. L’attività di ricerca si è dimostrata proficua dal punto di vista tecnico con la messa a punto di protocolli innovativi e con forti ricadute sulla riduzione dei tempi e costi d’analisi. Il debole segnale di possibili unità di stock andrà verificato in futuro mediante analisi più dettagliate discriminando meglio la storia di ogni singolo individuo.The European eel is euryhaline catadromous with a complex life cycle: spawning area, unique, is far from that of distribution. The species needs a stock management and its conservation. The problem is European: the stock is unique, distributed in Europe and North Africa, spawning in Atlantic Sea and is panmictic. There is concern about the decline of recruitment and catches of adults. The purpose of the project is to identify possible units of stock in the Italian peninsula. The research is based on the study of otoliths by morphometric and microchemical analyses . The otoliths contours are analyzed by elliptic Fourier function to discover any groups. Otoliths were polished to make: ageing, SEM microstructural investigations of larval stages, LA-ICP-MS microchemical analysis of the core to study the origin and along a transect core to edge to evaluate the development environment. Morphometric investigations show obvious ontogenetic pattern, but no location, gender or year of birth correlation. The microstructural investigations showed high organic content in the core, a common pattern of growth and key events of the larval stages, with an average of 212 daily rings. The microchemical reveals that the larvae develop into salt water until metamorphosis, then migrate to waters less salty. Analyses of samples born in the same year, showed two groups: wild and restocked. The profiles confirm that the adult stay in brackishwater. The development of innovative protocols and improved technics have guaranteed a strong reduction of time and cost of analysis. The weak signal of possible stock units will be further tested through more detailed analysis discriminating about the life history of each individual.
3
D'Angelo, Maria Carolina. "Analisi dell'accrescimento giornaliero della Sardina pilchardus nel Canale di Sicilia." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8283/.
Full textAbstract:
Lo studio effettuato riguarda l’accrescimento giornaliero della Sardina pilchardus, (Walbaum, 1792) tramite la lettura degli anelli di crescita giornaliera negli otoliti. Nel Mediterraneo centrale il lavoro svolto è il primo di questo tipo su S. pilchardus. Il campionamento è avvenuto durante la campagna oceanografica "Anchevatir 2012", 69 otoliti sono stati estratti da esemplari con lunghezza totale compresa tra 7 ed 12.5 cm e successivamente sottoposti ad inclusione, sezionamento e levigatura per la realizzazione di sezioni sottili. Sull’intero campione è stata stimata l’età con due metodi: lettura degli anelli giornalieri sotto microscopio e conteggio dei microincrementi tramite analisi d’immagine. L’età stimata è compresa tra i 90 e 230 giorni, tuttavia la maggior parte degli individui presenta un’età tra i 120 e 150 giorni. Inoltre è stata determinata la data di nascita degli esemplari, avvenuta tra Dicembre 2011 e Febbraio 2012. In seguito è stata condotta un’analisi della media dell’ampiezza degli incrementi per descrivere i pattern di crescita giornaliera: l’andamento risultante è crescente con il procedere dell’età fino a circa il 50° giorno, poi si stabilizza fino al 150°, infine i valori medi decrescono. La backcalculation ha permesso di stimare il tasso di accrescimento giornaliero della lunghezza del corpo. Sono state analizzate tre serie distinte per data di nascita (Dicembre 2011, Gennaio 2012 e Febbraio 2012); queste hanno mostrato pattern di accrescimento analogo. La crescita iniziale stimata è di 0.2 mm/d, raggiunge 0.6 mm/d intorno al 40° giorno, ed oltre il 100° si è osservato un decremento nell’accrescimento giornaliero, soprattutto nella serie di Dicembre. Le differenze più rilevanti nei pattern delle tre serie mensili sono state riscontrate nei valori medi fra Dicembre e Febbraio. L’analisi della temperatura media superficiale ha permesso di ipotizzare che questa crescita maggiore degli individui nati in Febbraio sia collegata all’aumento di temperatura registrato da Marzo in poi. Tale risultato suggerisce che le condizioni ambientali e quindi i ritmi metabolici e d’accrescimento nei mesi successivi a Febbraio sono più favorevoli rispetto ai mesi invernali.
4
D'Addelfio, Fabio. "Analisi morfometrica classica ed EFA (Elliptic Fourier Analysis) degli otoliti del genere Mullus in Alto - Medio Adriatico." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9546/.
Full textAbstract:
L’obiettivo del presente lavoro di tesi è stato quello di analizzare i campioni di otoliti delle due specie del genere Mullus (Mullus barbatus e Mullus surmuletus) per mezzo dell’Analisi Ellittica di Fourier (EFA) e l’analisi di morfometria classica con gli indici di forma, al fine di verificare la simmetria tra l’otolite destro e sinistro in ognuna delle singole specie di Mullus e se varia la forma in base alla taglia dell’individuo. Con l’EFA è stato possibile mettere a confronto le forme degli otoliti facendo i confronti multipli in base alla faccia, al sesso e alla classe di taglia. Inoltre è stato fatto un confronto tra le forme degli otoliti delle due specie. Dalle analisi EFA è stato possibile anche valutare se gli esemplari raccolti appartenessero tutti al medesimo stock o a stock differenti.
Gli otoliti appartengono agli esemplari di triglia catturati durante la campagna sperimentale MEDITS 2012. Per i campioni di Mullus surmuletus, data la modesta quantità, sono stati analizzati anche gli otoliti provenienti dalla campagna MEDITS 2014 e GRUND 2002. I campioni sono stati puliti e analizzati allo stereomicroscopio con telecamera e collegato ad un PC fornito di programma di analisi di immagine.
Dalle analisi di morfometria classica sugli otoliti delle due specie si può sostenere che in generale vi sia una simmetria tra l’otolite destro e sinistro. Dalle analisi EFA sono state riscontrate differenze significative in tutti i confronti, anche nel confronto tra le due specie. I campioni sembrano però appartenere al medesimo stock.
In conclusione si può dire che l’analisi di morfometria classica ha dato dei risultati congrui con quello che ci si aspettava. I risultati dell’analisi EFA invece hanno evidenziato delle differenze significative che dimostrano una superiore potenza discriminante. La particolare sensibilità dell’analisi dei contorni impone un controllo di qualità rigoroso durante l’acquisizione delle forme.
5
Traina, Anna <1979>. "Contributo allo studio del chimismo degli otoliti di Dicentrarchus labrax di allevamento : l’otolite come possibile tracciante ambientale." Doctoral thesis, Università Ca' Foscari Venezia, 2011. http://hdl.handle.net/10579/1102.
Full textAbstract:
In questo lavoro è stata studiata la composizione chimica di otoliti di Dicentrarchus labrax di allevamento al fine di verificare il possibile impiego degli otoliti come traccianti ambientali. Gli esemplari sono stati campionati da due allevamenti siciliani con caratteristiche diverse: l’allevamento “Ittica di Trappeto” situato nel Golfo di Castellammare (costa Nord) e l’allevamento “Sicilttica” di Licata (costa sud). Il primo è un tipo di allevamento off-shore in cui le gabbie sono poste lontano dalla costa e soggette ad un elevato idrodinamismo. Al contrario, il secondo impianto è di tipo in-shore in cui le gabbie si trovano all’interno dell’area portuale in cui il ricambio di acqua è sicuramente molto più limitato. In particolare, tramite ICP-AES (Inductively Coupled plasma Atomic Emission Spettrometry) sono state determinate le concentrazioni dei seguenti elementi: Sr, Fe, Mg, Ba, Cd, Mn e Zn; e tramite ICP-MS (Inductively Coupled plasma Mass Spectrometry) il gruppo dei Lantanidi (La,Ce, Pr, Nd, Sm, Eu, Gd, Tb, Gy, Ho, Er, Tm, Yb, Lu). Inoltre sono stati analizzati campioni d’acqua e di mangime prelevati nei due allevamenti. I risultati mostrano che le concentrazioni di Sr all’interno degli otoliti non differiscono significativamente nelle spigole dei due allevamenti distribuendosi in un simile intervallo. Fe, Mg, Mn e Cd mostrano invece concentrazioni maggiori a Licata mentre lo Zn è l’unico elemento che registra valori superiori negli otoliti dell’allevamento di Trappeto. L’analisi chimica dei mangimi mostra una maggiore concentrazione di Fe, Mg, Mn e Zn nei campioni di Licata. Le acque di Trappeto risultano arricchite soprattutto in Fe e Zn rispetto a quelle di Licata. Dai risultati ottenuti si può ipotizzare che il fenomeno di uptake degli elementi Fe, Mg, Mn e Cd all’interno degli otoliti sia influenzato sia alla elevata concentrazione degli stessi nell’acqua di mare o nei mangimi utilizzati e da possibili variazioni tipo endogeno dovuta all’eccessivo tasso metabolico nei pesci allevati. Tutti gli elementi studiati, tranne lo Sr sembrerebbero quindi essere influenzati dai parametri chimico-fisici che regolano le masse d’acqua all’interno dell’allevamento. Diversamente, la distribuzione di Sr all’interno dell’otolite, è probabilmente principalmente controllata dalla preferenziale incorporazione nei siti del Ca e quindi alla struttura dell’aragonite. L’ elevata concentrazione di Zn, all’interno degli otoliti di Trappeto può essere spiegata con sorgenti antropiche provenienti dagli insediamenti industriali (distilleria) che insistono nel Golfo di Castellammare e che scaricano i propri reflui a mare. Lo studio delle distribuzione dei lantanidi ha evidenziato che gli otoliti di Trappeto mostrano un “seawater-like pattern” suggerendo il possibile utilizzo dell’otolite come proxy per lo studio della chimica dei lantanidi in acqua di mare, inoltre le anomalie di Ce hanno dato indicazioni sulle condizioni ossigenazione dei due allevamenti. Lo studio della chimica dell’otolite ha consentito di distinguere gli esemplari provenienti dai due allevamenti (Licata e Trappeto) suggerendo che la distribuzione degli elementi in tracce nei carbonati biogenici, possa costituire un valido tracciante ambientale. Tale studio si inserisce all’interno di una più ampia tematica di ricerca sullo studio degli otoliti considerati importanti indicatori della “life history” di specie ittiche. Riteniamo comunque importante effettuare ulteriori approfondimenti mirati a verificare la possibile relazione tra le variabili dell’acqua (salinità, temperatura e chimismo dell’ambiente), la composizione mangimistica e la composizione chimica dell’otolite anche al fine di poter utilizzare gli stessi otoliti come discriminante per il monitoraggio delle condizioni ambientali d’allevamento.In this work we studied the chemical composition of otoliths of cultured Dicentrarchus labrax in order to verify the possible use of otoliths as environmental tracers. Specimens were sampled from two Sicilians farms with different characteristics: the farm "Ittica Trappeto" located in the Gulf of Castellammare (North Coast) and “ Sicilttica "Licata (South Coast). The first is an off-shore farm where the tanks are placed far from the coast, in a area characterized by high hydrodynamism. The second one is an in-shore farm where the tanks are located inside the port where the water is certainly much more limited. Particularly, we analyzed concentrations of Sr, Fe, Mg, Ba, Cd, Mn and Zn using ICP-AES (Inductively Coupled Plasma Atomic Emission Spettrometry); ICP-MS (Inductively Coupled plasma Mass Spectrometry) were used for determination of Rare Elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, GY, Ho, Er, Tm, Yb, Lu). Were also analyzed samples of water and food from the two farms. Results show that concentrations of Sr in the otoliths have a similar range of distribution and not significantly differ between the two farms. Fe, Mg, Mn and Cd show, however, higher concentrations in Licata and Zn is the only element witht an higher values in the otoliths from Trappeto. Chemical analysis of food shows an higher concentration of Fe, Mg, Mn and Zn in samples of Licata. Trappeto water is enriched mainly in Fe and Zn than that of Licata. Our results may suggest that the uptake in the otoliths of elements such Fe, Mg, Mn and Cd is influenced either from the high concentration of them in sea water or in the food and from an higher metabolic rate of cultured fishes. All the elements, except Sr, seems to be influenced by physical-chemical parameters that control water properties in the farm. On the contrary, distribution of Sr within otolith, is probably controlled by the preferential incorporation into the Ca sites, and so in the then the Aragonite structure. Elevated concentration of Zn in the otoliths of Trappeto can be explained by the anthropogenic sources. Indeed in the Gulf of Castellammare there is a industrial sites (distillery) that release their waste into the sea. The study of distribution of Rare Elements showed that the "seawater-like pattern of otoliths of Trappeto suggest the possible use of otolith as a proxy for the study of the chemistry of Rare Elements in seawater. Furthermore Ce anomalies gave indications of oxygenation conditions in the two farms. The study of chemistry of otoliths allowed to distinguish the specimens among the two farms (Licata and Trappeto) suggesting that the distribution of trace elements in biogenic carbonates, may be a useful environmental tracer. This study is part of a broader research on the study of the otoliths considered as important indicators of the “life history” of fish species. We believe, however, that further studies are required with the aim to verify the possible relationship between the variables of water (salinity, temperature and chemistry of the environment), food composition and chemical composition of otolith also in order to use the same otoliths for monitoring environmental conditions for breeding.
6
Alia, Andrea. "Struttura di età del genere Mullus in Alto-Medio Adriatico mediante lettura di otoliti e frequenze di taglia." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9600/.
Full textAbstract:
Scopo di questo studio è la determinazione delle strutture di età delle specie Mullus barbatus e Mullus surmuletus, pescate in Alto-Medio Adriatico durante le campagne di ricerca MEDITS e GRUND mediante la lettura degli anelli stagionali degli otoliti e delle frequenze di taglia. I campioni di otoliti sono stati prima estratti e poi lavati con sonicatore e acquisiti al computer. Sono state successivamente prese le misure dei radius ed è stata fatta una prima lettura degli anelli. Un subcampione è stato poi scelto per applicare altri due metodi di lettura degli anelli: la bruciatura e la colorazione, preceduta dal taglio dell’otolite. Sono stati poi levigati e lucidati gli otoliti dei giovanili per un conto degli annuli giornalieri. L’analisi dati, svolta tramite il software Rstudio, ha permesso di calcolare non solo le strutture di età, ma anche di osservare le distribuzioni dei campioni per classi di profondità e latitudine, confrontare le strutture di taglia e calcolare le chiavi di età-lunghezza, l’accrescimento somatico con le relazioni lunghezza-peso e l’equazione di Von Bertalanffy e l’accrescimento dell’otolite tramite i rapporti radius-taglia e radius-età e il tasso di incremento dei radius. Infine sono stati anche confrontati i tre metodi di lettura degli anelli al fine di stabilirne il migliore. Le due specie hanno mostrato una grande maggioranza di individui di 1 e 2 anni, soprattutto nella zona settentrionale e centrale dell’area di studio a profondità entro i 100 m. Differenze specifiche sono poi state trovate nel confronto tra le strutture di taglia e le relazioni lunghezza-peso e per il tasso di accrescimento K dell’equazione di Von Bertalanffy. Alta poi è la correlazione tra la misura dei radius e la taglia e l’età. Diverso è anche il tasso degli incrementi dei radius tra primo-secondo anno e secondo-terzo anno.
7
Marziliano, Lucia. "Gli otoliti dei Triglidae (Teleostei, Scorpaeniformes): un approccio innovativo allo studio comparativo della forma e della struttura cristallina." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/2411/.
Full text
8
Angileri, Paolo Maurizio Maria. "Struttura di età di nasello (Merluccius merluccius, Linnaeus, 1758) in alto-medio Adriatico mediante analisi degli otoliti e frequenza di taglia." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8090/.
Full textAbstract:
The aim of present study is to define the general framework of Merluccius merluccius population structure, to estimate the growth rate and to assess the recruitment dynamics of juveniles from Northern and Central Adriatic, through otoliths analysis.
The otoliths of hake specimens collected during the MedITS trawl survey in the 2012 in GSA 17, were cleaned and 102 otoliths out of 506 were embedded, sectioned, grindined and polished to obtain frontal and sagittal sections. The whole sample were analysed under stereomicroscope and optical microscope, with camera and connected to PC provided of an image analyses program.
The frequency analysis of size classes and age revealed that the species is dominated by hake with >200mm TL and > one year old. The fish average size of M. merluccius at the end of the first year of life is about 199 mm TL. Allometrics analyses between fish TL and Feret (major axis), MiniFeret (minor axis), Area, Perimeter, showed a direct proportionality among lengths.
Among the 88 otoliths sections analysed, the number of daily increments read ranged from 86 to 206, within 55 and 175mm TL range. The age estimate ranged from about 2-3 to 9 months and the growth rate from 20.99 to 27.15mm TL. The hatch-date distribution, obtained by back calculation, showed that the hatching occurs in November-March.
In conclusion, strong preventive measures are needed for hake adults because the success of this species seems to be linked to deep water ecosystem protection where big spawners dwell.
9
Akin, Faith W. "Otolith Assessment." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/2434.
Full text
10
Mapp, J. "Morphometric otolith analysis." Thesis, University of East Anglia, 2015. https://ueaeprints.uea.ac.uk/59388/.
Full textAbstract:
Fish otoliths have long played an important role in sustainable fisheries management. Stock assessment models currently used rely on species specific age profiles obtained from the seasonal patterns of growth marks that otoliths exhibit. We compare methods widely used in fisheries science (elliptical Fourier) with an industry standardised encoding method (MPEG7 - Curvature-Scale-Space) and with a recent addition to shape modelling techniques (time-series shapelets) to determine which performs best. An investigation is carried out into transform methods that retain size-information, and whether the boundary encoding method is impacted be otolith age, performing tests over three 2-class otolith datasets across six discrete and concurrent age groups. Impact of segmentation methods are assessed to determine whether automated or expert segmented methods of boundary extraction are more advantageous, and whether constructed classifiers can be used at different institutions. Tests show that neither time-series shaplets nor Curvature-Scale-Space methods offer any real advantage over Fourier transform methods given mixed age datasets. However, we show that size indices are most indicative of fisheries stock in younger single-age datasets, with shape holding more discriminatory potential in older samples. Whilst commonly used Fourier transform methods generally return best results; we show that classification of otolith boundaries is impacted by the method of boundary segmentation. Hand traced boundaries produce classifiers more robust to test data segmentation methods and are more suited to distributed classifiers. Additionally we present a proof of concept study showing that high energy synchrotron scans are a new, non-invasive method of modelling internal otolith structure, allowing comparison of slices along near infinite numbers of virtual complex planes.
11
Murnane, Owen D. "Otolith Function Tests." Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etsu-works/1941.
Full text
12
Randon, Marine. "Structure spatiale et connectivité au sein du stock de sole commune de Manche Est : Apport d’une approche holistique multitraceur." Thesis, Rennes, Agrocampus Ouest, 2020. http://www.theses.fr/2020NSARH112.
Full textAbstract:
La sole commune (Solea solea) est un poisson plat nourricerie-dépendant ayant été surexploité en Manche Est (division VIId). L’une des causes de ce déclin pourrait être le décalage entre l’unité de gestion (stock) et l’unité fonctionnelle (population). L’objectif de cette thèse était de déterminer la structure spatiale du stock de sole commune de Manche Est en se focalisant sur les stades de vie préadultes et adultes et de statuer sur le potentiel décalage entre l’unité de stock et la population sous-jacente. Pour cela, une approche holistique multitraceur a été développée en combinant des approches populationnelles et individuelles.D’abord, une étude de la croissance populationnelle et de la synchronie des abondances aux âges a mis en évidence l’existence d’un signal à long terme de structure spatiale du stock en trois sous-unités avec l’isolement probable de l’une d’entre elles. Ensuite, des analyses génétiques, de forme des otolithes et de microchimie des otolithes ont mis en évidence une structure spatiale en trois sousunités. Enfin, un Indice semi-quantitatif de Différentiation du Stock a suggéré une forte structure spatiale en trois sous-unités. Ainsi, cette thèse a démontré une structure de type métapopulation de la sole commune en Manche Est qui devrait être prise en compte dans le processus d’évaluation et de gestion du stock afin d’atteindre une gestion durableThe common sole (Solea solea) is a nursery-dependent flatfish that has been overexploited in the Eastern English Channel stock (division VIId). An explanation of such decline could be the misalignment between the management unit (stock) and the biological unit (population). This thesis aimed at assessing the spatial structure of the Eastern English Channel stock of common sole by focusing on sub-adults and adults and determining the potential mismatch between the stock unit and the underlying population. To do so, a multitracer holistic approach was developed by combining population and individual-based approachesFirst, analyses of population growth and synchrony of abundances-at-age series revealed the existence of a long-lasting signal of spatial stock structure made of three subunits with potential isolation ofone of these subunits. Then, genetics, otolith shape and otolith microchemistry analyses highighted three subunits within the stock. Finally, a semiquantitative Stock Differentiation Index suggested a strong spatial structure in three subunits. Therefore, this thesis evidenced a metapopulation structure of the common sole of the Eastern English Channel that should be integrated in the assessment – management process to provide a sustainable exploitation of the stock
13
Akin, Faith W., and Owen D. Murnane. "Tests of Otolith Function." Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/etsu-works/1937.
Full text
14
Hall, Courtney D., Faith W. Akin, and Owen D. Murnane. "Otolith Dysfunction and Postural Stability." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/1929.
Full text
15
Murnane, Owen D. "Clinical Assessment of Otolith Organ Function." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/1930.
Full text
16
Akin, Faith W., and Owen D. Murnane. "ASHA Perspectives: Clinical Assessment of Otolith Function." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etsu-works/1794.
Full textAbstract:
The two otolith organs (the saccule and utricle) are positioned perpendicular to each other and sense linear acceleration, head tilt, and gravity, with the primary role of providing input to the vestibulospinal reflex for postural stability. The vestibulospinal reflex serves to modulate posture via two descending pathways that aid in tonic contractions of the antigravity muscles in the arms and legs (lateral vestibulospinal tract) and activate neck motoneurons for the coordination of neck and eye movements (medial vestibulospinal tract). The lateral vestibulospinal tract receives the majority of its input from the otoliths and the cerebellum, whereas the medial vestibulospinal tract receives the majority of its input from the semicircular canals.
17
Lavergne, Edouard. "Biodiversité des poissons estuariens de l'Ile de Socotra (Nord-Ouest de l'Océan Indien) : du peuplement ichtyologique au fonctionnement des populations de Terapon jarbua." Thesis, Brest, 2012. http://www.theses.fr/2012BRES0093/document.
Full textAbstract:
La compréhension de la connectivité entre les nourriceries estuariennes et les habitats marins est fondamentale pour l'étude de la dynamique des peuplements et des populations de poissons et pour la conception de stratégies efficaces de conservation et de gestion des pêches. Le but de ce travail était donc de fournir une première référence faunistique et écologique des poissons des estuaires et du lagon de l'île de Socotra (Nord-Ouest de l'Océan Indien) pour les gestionnaires de la zone côtière, avec un accent particulier sur le fonctionnement des populations d'une espèce sentinelle: Terapon jarbua. Dans cette étude, une approche multidisciplinaire a été développée afin de comprendre le fonctionnement et l'importance des estuaires (TOCE's : Temporarily Open / Closed Estuaries) et du lagon de l'île de Socotra pour les poissons marins. Différents outils de la biologie et de la chimie (taxonomie, écologie, phylogéographie, génétique des populations, microstructure et microchimie des otolithes) ont été utilisés et les principales conclusions de ce travail sont les suivantes: 1) Les estuaires de Socotra sont composés de 64 espèces dans 30 familles, un chiffre élevé par rapport aux normes régionales. La comparaison avec les inventaires faunistiques d'Afrique du Sud et du Yémen suggère que Socotra joue le rôle de tremplin biogéographique, en permettant la connexion d'une grande variété de groupes taxonomiques provenant de différentes unités biogéographiques. De plus 33 des 64 espèces recensées sont considérées comme importantes pour l'économie locale, soulignant l'importance primordiale des estuaires comme sites de fraie et nourriceries, pour le fonctionnement durable des services écosystémiques. 2) La phylogéographie et la structure génétique des populations de T. jarbua ont été analysées considérant des marqueurs de type Cytochrome c Oxydase sous-unité I et microsatellites. Une différenciation génétique élevée et significative a été observée à l'échelle de l'Indo-Ouest Pacifique. Trois groupes de populations ont pu être identifiés, le groupe du Nord-Ouest de l'Océan Indien (Socotra, Yémen et Iran), le groupe de l'Ouest de l'Inde et le groupe de la Mer de Chine. Cependant, les grandes différences nucléotidiques observées soulèvent certaines questions concernant l'identification de l'espèce et suggèrent que T. jarbua pourrait être en réalité un complexe d'espèces, en dépit du fait que la coloration caractéristique de T. jarbua facilite son identification. A l'échelle plus restreinte du Nord-Ouest de l'Océan Indien, une expansion récente de la population de T. jarbua après des extinctions locales au cours des glaciations du Pléistocène pourrait expliquer la faible mais significative différenciation génétique. Le génotypage des marqueurs microsatellites souligne une différenciation génétique relativement élevée et significative entre les estuaires, sur le secteur Socotra-Yémen. Si la distance géographique n'est pas un facteur structurant majeur des populations de T. jarbua dans la région du Golfe d'Aden, le lien étroit entre les juvéniles T. jarbua et les TOCE, ainsi que les phénomènes d'ouverture associés à de possibles goulots d'étranglement démographiques dans ces systèmes côtiers, peuvent expliquer la mise en place d'une différenciation génétique locale significative entre les estuaires. Bien que l'environnement dynamique de la région puisse limiter la différenciation génétique, la courte durée du stade larvaire de cette espèce (25 jours estimés par la lecture des microstructures de l'otolithe) et la possible rétention des larves dans certains secteurs peuvent réduire l'homogénéisation à plus grande échelle géographique. 3) Les analyses de la composition élémentaire des nucleus d'otolithes suggèrent l'existence de plusieurs zones de fraie marines ; ces données confrontées aux résultats des investigations en génétique des populations suggèrent un modèle régional de métapopulation composée de sous-populations ouvertes…Understanding connectivity between estuarine nurseries and marine habitats is fundamental to explore fish population dynamics and to the design of effective conservation and fisheries management strategies. The aim of this work was to provide the first faunistic and ecological baseline of Socotra Island (North-Western Indian Ocean) estuaries and lagoon fishes for governmental coastal managers and decision makers, with a particular focus on the population functioning of a sentinel species: Terapon jarbua. In this study, a multidisciplinary approach was developed to understand the functioning and importance of Socotra estuaries (TOCE's: Temporarily Open / Close Estuaries) and lagoons for marine fishes. Several biological and chemical tools (taxonomy, ecology, phylogenetics, population genetics, otolith microstructure, otolith microchemistry) were used and the main findings of this work are as follows: 1) Socotra estuaries are composed of 64 species in 30 families, a high figure by regional standards. The comparison with faunistic records from South Africa and Yemen mainland provides further support to Socotra's function as a biogeographic "stepping stone" for certain species. Moreover 33 out of the 64 recorded species were considered as relevant species for the local economy. This underscores the paramount importance of these coastal water bodies as spawning and nursery sites and for the sustainability of vital provisioning ecosystem services. 2) The phylogeography and the genetic structure of T. jarbua populations were analyzed considering Cytochrome c Oxidase subunit I and microsatellites and underlined two patterns of genetic structure. A high and significant genetic differentiation was observed at the scale of the Indo-West Pacific. Three population clusters could be drawn, the North-Western Indian Ocean cluster (Socotra, Yemen and Iran), the West Indian Shelf cluster and the Chinese Sea cluster. However, the large number of nucleotide differences raised some issues concerning the species identification as T. jarbua might be a species complex, despite the fact that it shows a characteristic color pattern easily identifiable. At the restricted scale of the North-Western Indian Ocean, recent population expansion after local extinctions during the Pleistocene glaciations might explain small but significant genetic differentiation. Considering microsatellites, genotyping highlighted a relatively high and significant genetic differentiation between estuaries, over the Socotra-Yemen region. Geographical distance is not a major structuring factor for T. jarbua populations in the wider Gulf of Aden region. The strict link between juvenile T. jarbua and TOCE's, and the opening/closing associated with possible demographic bottlenecks, could increase the local differentiation among estuaries. Although the dynamic environment of the region driven by the monsoon system could reduce the genetic differentiation between populations, the short larval stage duration and potential larval retention in particular sectors might reduce homogenization over larger geographical scale. 3) The analysis of otolith nucleus elemental composition suggested the existence of several marine spawning grounds, thus confirming the population genetics approach suggesting a regional model of metapopulation composed of open subpopulations (i.e. multiple sources and more or less pronounced mixtures of larval flows displaying a spatio-temporal variability). In addition, transect Sr:Ba ratio analysis along the otolith growth axis showed clear pattern of post larval migrations into estuarine nurseries where individuals remain for two years. Finally, otolith edges elemental fingerprint assignation tests to nurseries were highly accurate and could conduct in the future to the assessment of the contribution level of a particular nursery to the adult population of T. jarbua as well as others ecologically or economically important species
18
Loubere, Alexander. "Identifying Recruitment Sources, Dispersal and Movement of Sauger in the Ohio River Using Otolith Microchemistry." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2514.
Full textAbstract:
Sauger Sander canadensis is a native, migratory sportfish found in large rivers and riverine impoundments, primarily in the central United States. The migratory nature of this species requires access to un-impounded sections of river in order to complete reproduction and other aspects of life history. This requirement, along with their popularity as a gamefish, has resulted in widespread declines in sauger populations throughout their range due to habitat alteration and fragmentation combined with harvest pressure. The lower Ohio River supports a sauger population that is impeded by multiple high head dams and is heavily exploited by recreational anglers. However, despite high popularity among anglers, relatively little is known about large-scale movement patterns of sauger in the lower Ohio River. Additionally, the contribution that tributaries make to the population in terms of both recruitment and use by adults has not been assessed. I identified analysis of trace elements and stable isotopes in otoliths as techniques that could help quantify the role that tributary habitats play in the Ohio River sauger fishery. First, I collected water from the Ohio River and its larger tributaries in order to test the null hypothesis that there were no persistent differences in Sr:Ca, δ18O, and Ba:Ca among rivers. Water and otolith Sr:Ca, δ18O, and Ba:Ca from Sander spp. were then compared to test the null hypothesis that there is no significant relationship between Sr:Ca, δ18O, and Ba:Ca in the water and Sr:Ca, δ18O, and Ba:Ca measured in the otolith. I applied this relationship to Sr:Ca, δ18O, and Ba:Ca measured in the core of sauger otoliths collected in four navigational pools to test the null hypothesis that there were no differences in sauger recruitment sources among the four pools sampled on the lower Ohio River. Finally, I analyzed changes in Sr:Ca, δ18O, and Ba:Ca across otolith transects of the same fish to identify movements between the Ohio River and tributary habitats and test the null hypothesis that there were no differences in movement probability by age or assigned origin. Analysis of water chemistry indicated significant differences in Sr:Ca between the Ohio River and its tributaries, but not among tributaries. There were no significant differences in either water Ba:Ca or δ18O between the Ohio River and its tributaries. Comparison of water and otolith chemistry of known origin individuals yielded significant relationships for Sr:Ca and δ18O, but not Ba:Ca. As a result, only Sr:Ca was used for origin and movement assessments. Analysis of otolith core Sr:Ca indicated that tributaries are an important source of recruitment for the lower Ohio River sauger fishery. Otolith Sr:Ca consistent with reaches upriver of the study area were also prevalent in otolith core samples, indicating upriver sources are important for maintaining population density in the study area. Movement analysis indicated high probabilities of movement to upriver habitats in all pools, along with high movement probability to tributary habitats among fish collected in all pools. The data indicated that adult sauger in the lower Ohio river were recruited from multiple sources, and there is a high degree of exchange between the Ohio River and its tributaries. High recruitment and movement probability from upriver areas of the Ohio River indicated that the study area I identified does not encompass all of the river used by the population(s) sampled. Managers should focus on unification of regulations and sampling protocol to reflect this expansive range.
19
Zhang, Ziyang. "Studies on otolith growth increments in Tilapia species." Thesis, Bangor University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291686.
Full text
20
張永魁 and Yongkui Zhang. "Functional development of otolith afferents in postnatal rats." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31242716.
Full text
21
Zhang, Yongkui. "Functional development of otolith afferents in postnatal rats." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23295089.
Full text
22
Jemaa, Sharif. "Étude de la structure des populations et du régime alimentaire de l'anchois européen (Engraulis encrasicolus) et de la sardine européenne (Sardina pilchardus) : relations avec l'environnement." Thesis, Littoral, 2014. http://www.theses.fr/2014DUNK0391/document.
Full textAbstract:
L'anchois européen et la sardine européenne sont sujets à de fortes pressions de pêche et les stocks sont soit pleinement exploités soit surexploités. Cette situation tient au partie au fait qu'un grand nombre de pêcheries d'anchois et de sardines sont gérées sur la base de zones géographiquement délimitées par le CIEM, le CGPM ou d'autres organisations régionales sans qu'il y ait nécessairement de véritable cohérence entre ces limites administratives et les processus biologiques. Dans ce contexte, l'objectif principal de la thèse a été d'explorer à partir de l'analyse de la forme de l'otolithe la structuration des populations de sardines et d'anchois à petite (régionale) et grande (aire de répartition) échelles spatiales. À petite échelle spatiale, nous avons essayé d'analyser comment les structures océanographiques et géographiques comme les fronts hydrologiques et les détroits peuvent affecter la structure des populations. À grande échelle spatiale, les structures des populations mises en évidence par l'analyse de la forme de l'otolithe sont comparées et discutées avec les résultats des études génétiques. Les résultats montrent des structurations plus complexes chez l'anchois que chez la sardine. Contrairement à la sardine, les caractéristiques hydrologiques comme le front hydrologique Almeria-Oran (AOF) et le détroit de Gibraltat constituent des barrières à la dispersion et au mélange des anchois. En matière de gestion des stocks de sardines et d'anchois, nos résultats proposent de nouveaux découpages et suggèrent une révision des limites des stocks actuellement retenus. Les populations de petits poissons pélagiques sont connues pour être particulièrement sensibles aux fluctuations de l'environnement. La deuxième partie du travail de thèse a été consacrée à l'étude de l'écologie alimentaire de la sardine et de l'anchois à grande échelle spatiale en Méditerranée et en Atlantiqu NE. Anchois et sardines sont essentiellement zooplantonophages. Ils consomment majoritairement des copépodes (59.4% des proies identifiées pour la sardine et plus de 78% chez l'anchois). La comparaison des régimes alimentaires suggère un faible chevauchement entre les deux espèces particulièrement dans les zones de fortes productivités biologiques. Toutefois, en Méditerranée, où les eaux sont connues pour être oligotrophiques et donc peu productives, il peut y avoir chevauchement des niches trophiques des 2 espècesThe European anchovies and sardines are subject to heavy fishing pressure and their stocks are either fully exploited or overexploited. This is partly because many anchovy and sardine fisheries are managed on the basis of geographical areas bounded by ICES, GFCM and other regional organizations without necessarily true coherence between these administrative boundaries and the biological processes. In this context, the main objective of the thesis is to explore the population structure of sardines and anchovies at small (regional) and large (distribution range) spatial scales from the analysis of the otolith shape. At a smaller spatial scale, we tried to analyze how oceanographic and geographic structures, such as, hydrological fronts and Strait, can affect population structure. At larger spatial scales, population structures revealed by the analysis of otolith shapes were compared and discussed with the results of genetic studies. The results showed more complex population structure in anchovies than in sardines. Unlike sardines, hydrological characteristics, such as, the hydrological Almeria-Oran Front (AOF) and the Strait of Gibraltar constitute barriers that limit the dispersal and mixing of anchovies. In managing stocks of sardines and anchovies, our results suggest new division and suggest a readjustment of stocks currently held. Population of small pelagic fish are known to be particularly sensitive to changes in the environment. The second part of the thesis is devoted to studying of the feeding ecology of sardines and anchovies at large spatial scale in the Mediterranean and North-eastern Atlantic. Anchovies and sardines are essentially zooplantonophages. they mainly consume copepods (59.4% of identified prey for sardines and over 78% for anchovies). Comparing diets suggests little overlap between the two species, particularly in areas of high biological productivity. However, in the Mediterranean, where the waters are known to be oligotrophic and thus unproductive, the trophic niches of the two species may overlap
23
Marohn, Lasse [Verfasser]. "Microchemical analyses of otoliths in Baltic Sea fish : Possibilities and limitations of otolith elemental analysis to describe individual life history and stock characteristics of fish in the Baltic Sea / Lasse Marohn." Kiel : Universitätsbibliothek Kiel, 2011. http://d-nb.info/1020244720/34.
Full text
24
Jamieson, Robyn E. "Environmental history of northern cod from otolith isotopic analysis /." *McMaster only, 2001.
Find full text
25
Lefkaditis, Dionysios. "Intelligent visual otolith classification for bony fish species recognition." Thesis, University of Brighton, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500781.
Full textAbstract:
The study of otoliths is a well-established source of information for understanding the life offish and fish populations. Conducting fish species identification from otolith samples found in the stomach contents of marine fish-eating animals finds interesting applications such as dietary studies, stock monitoring, assessment and management. Fish species identification can provide useful data for climatology, archaeology and palaeontology research, as otoliths can be sourced from geological sediments or archaeological excavations. Analysing an otolith is a highly complex and time-consuming procedure Therefore, an automated otolith classification system can prove to be a vital tool for a wide variety of scientific research. The aim of the programme of work seeks the development of a novel automated fish species identification system. The main focus of this investigation is on the commercially interesting fish of the Northern Aegean Sea. The methodology described in this thesis exploits the inherent shape variability offish otoliths according to their corresponding species. This is based on the processing and analysis of images acquired using a stereoscopic microscope fitted with a digital camera. A compact feature vector is then constructed out of a list of candidate descriptors derived from the morphology as well as the image statistics of the otoliths. The identification is carried out by an intelligent classifier based on an artificial neural network. Several configurations of multi-layer perceptron, radial basis function and hybrid neural networks are considered in pursuit of a practical and expandable classification system.
26
Pflugeisen, Bethann Mangel. "Analysis of Otolith Microchemistry Using Bayesian Hierarchical Mixture Models." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275059376.
Full text
27
Akin, Faith W. "Advanced Techniques in Vestibular Assessment: Tests of Otolith Function." Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/etsu-works/2444.
Full text
28
Andersson, Magdalena. "Utvärdering av rörelsemönster hos öring (Salmo trutta) utifrån otolitmikrokemi." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-34636.
Full textAbstract:
The classic view of trout (Salmo trutta) life history is that trout begins its life in freshwater, migrates to the ocean after about 1-4 years and then returns to freshwater to spawn. As trout fry have been caught at the mouth of the River Emån, near the Baltic Sea, researchers have speculated that some trout emigrate during their first year of life. The purpose of this study was to describe the variation in the length of time trout reside in freshwater before they migrate to the ocean for the first time. Another purpose was to investigate whether it was possible to discern where and how long the fish spent in freshwater and saltwater during different parts of their lives. Between 2007 and 2009, 23 adult trout were captured in the River Emån in southeastern Sweden. From each fish, a microchemical analysis of the sagitta otolith was conducted. The analysis focused on measuring the ratio of strontium:calcium from the center of the otolith to its outer edge at 6μm intervals. Based on this analysis, I found that 26% of the trout in the population emigrated to sea before they had reached the age of one. The largest proportion (48%) of trout emigrated between 1 to 2 years of age. The results of my study indicated that there was a significant correlation between age and the number of times that the fish remained in freshwater. I also analyzed the ratio of zinc:calcium and manganese:calcium. The analysis of zinc showed annual fluctuations, including a high value during the fish's first year and a seasonal pattern, with higher values of Zn:Ca in spring and summer. My results also showed some variation of the trace element manganese, half of the fish showed a peak in their first year. The results of this study indicate that by analyzing the concentrations of trace elements in otoliths one can describe individual variation in brown trout movement patterns and life history.Den klassiska bilden för örings (Salmo trutta) livshistoria är att den växer upp i sötvatten, vandrar ut till havet efter ca 1-4 år för att sedan återvända till sötvatten för att leka. Då det fångats laxfiskyngel nära mynningen av Emån vid Östersjön har man funderat på om en del öringar utvandrar till havet under sitt första levnadsår. Syftet med denna studie var att beskriva variation i hur lång tid öringar vistas i sötvatten innan de utvandrar till havet för första gången. Ytterligare ett syfte var att undersöka om det gick att urskilja var och hur länge fiskarna vistades i söt- och saltvatten under olika delar av fiskarnas liv. Under åren 2007 till 2009 infångades 23 vuxna öringar i Emån i sydöstra Sverige. Från varje individ gjordes en mikrokemisk analys av sagittaotoliternas spårämnes sammansättning. En analys handlade om att mäta koncentrationen strontium:kalcium från otolitens mitt till dess ytterkant i steg om 6μm. Baserat på denna analys fann jag att 26 % av öringarna i populationen utvandrat till havet innan de hade nått ett års ålder. Den största andelen öringar utvandrade mellan 1 till 2 års ålder. Resultatet av min undersökning indikerade att det fanns ett signifikant samband mellan ålder och antal gånger som fisken vistats i sötvatten. Jag utförde även analys av kvoten zink:kalcium och mangan:kalcium. Analysen av zink visade på årliga svängningar med bl.a. ett högt värde under individens första år samt ett säsongsmönster med högre värden under vår och sommar. Mina resultat påvisade även en viss variation av spårämnet mangan där hälften av individerna markerade en tydlig topp under sitt första år. Resultaten från denna studie visar att genom att analysera spårämnens olika koncentrationer i otoliter kan man beskriva individuell variation i öringens rörelsemönster och livshistoria.
29
Wilhelm, Margit Renate. "Growth and otolith zone formation of Namibian hake, merluccius capensis." Doctoral thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/10785.
Full textAbstract:
Includes bibliographical references.Life history traits and tactics of commercially important Namibian shallow-water hake, Merluccius capensis, were investigated in relation to their environment. A time series of length-frequency distributions (LFDs) from otoliths collected from fur seal scat samples was used to identify cohorts and calculate the approximate hatchdates and growth rates of young M. capensis from 1994 to 2009. Monthly otolith samples of five of these cohorts (1996, 1998, 2002, 2005 and 2006) were used to evaluate the translucent zone periodicity over the first 21 months of their life. Additionally, LFDs from research surveys and commercial samples were used to calculate growth rates for M. capensis up to 65 cm total length (TL), and to further validate the translucent zone formation of three of the five cohorts (1996, 1998 and 2002) on fish up to 3.5 years old.
30
Tournois, Jennifer. "Rôle des nourriceries lagunaires dans le maintien d’une espèce de poisson à forte valeur commerciale, la daurade royale (L. 1758, Sparus aurata)." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20198/document.
Full textAbstract:
De nombreuses espèces de poissons marins côtiers à forte valeur économique ont un cycle de vie complexe impliquant des migrations saisonnières entre l'environnement marin et les habitats côtiers. Une meilleure compréhension de leur cycle de vie, en particulier l'identification de leurs nourriceries clés, est vitale pour la gestion durable des stocks de poissons exploités. Cette étude évalue la fonction de nourricerie des lagunes côtières du Golfe du Lion (Méditerranée NO) pour la daurade royale, Sparus aurata, une espèce d'intérêt commercial, dont les juvéniles colonisent ces habitats chaque année pendant leur premier été de vie. La qualité en tant que nourriceries de quatre lagunes aux conditions environnementales contrastées a été estimée par des mesures de la condition (indices de Fulton et TAG:ST) et du taux de croissance (par otolithométrie) des juvéniles. Les résultats montrent une condition et une croissance des juvéniles plus importantes dans les deux lagunes les plus dessalées et peu profondes (Bages-Sigean et Mauguio) que dans les deux lagunes profondes aux salinités proches de celle de la mer (Salses-Leucate et Thau). Les différences spatiales, stables dans le temps, de signatures élémentaires des otolithes ont permis de valider ces dernières comme tag naturel pour discriminer les habitats des juvéniles de daurade royale. Ainsi, l'identification a posteriori des nourriceries colonisées au stade juvénile chez des adultes pêchés le long de la côte du Golfe du Lion a pu être réalisée. Les estimations de la contribution relative des habitats des juvéniles au stock d'adultes (selon la contribution absolue ou la contribution par unité de surface) révèlent l'importance globale des lagunes pour le maintien des populations. Les lagunes les plus dessalées ont été identifiées comme les meilleures nourriceries de la zone d'étude. Le rôle important de la lagune de Thau pour le maintien des stocks de poissons a également été mis en évidence. Les résultats dans leur ensemble montrent une certaine convergence entre les estimations d'exports potentiel et réel des habitats des juvéniles. Les conclusions de cette étude sont primordiales pour la gestion et la protection des habitats clés des juvéniles ainsi que les ressources exploitées qui en dépendentMany coastal marine species of major socio-economic importance exhibited complex life histories include seasonal migrations between offshore marine environments and inshore coastal habitats. An adequate scientific understanding of their life cycle and, in particular the identification of the most significant juvenile nursery grounds are urgently needed for the sustainable management of fish stocks. This present study investigated the nursery function of coastal lagoons in the Gulf of Lions (NW Mediterranean) for a valuable fish species, the gilthead sea bream Sparus aurata, whose juveniles colonize these habitats each year for feeding and growing over their critical first summer of life. Habitat quality of four contrasted lagoons was measured with body condition (Fulton and muscle TAG/ST indices) and otolith growth rate of juveniles. Results showed better condition and higher growth rates in juveniles inhabiting the two shallow and brackish lagoons (Bages-Sigean, Mauguio) compared to the two deeper and more saline lagoons (Salses-Leucate and Thau). Otolith elemental signatures were temporally validated as natural tags to discriminate among juvenile habitats, allowing the retrospective identification of juvenile origin of S. aurata adults captured along the Gulf of Lions coastline. The estimations of relative contributions of juvenile habitats to adult stocks revealed the overall significance of lagoons for the maintenance of population. While, brackish lagoons were identified as the major contributors and best nursery habitats in the area, the importance of Thau lagoon to sustain fish stocks was also highlighted. Combined results of this research revealed some agreement between potential and effective export estimates from juvenile habitats. Information derived from this study is highly valuable for the sustainable management and protection of juvenile habitats, and the fishery resources that depend on them
31
Barrios, rodriguez Alexander José. "Influence des variations des facteurs environnementaux sur la croissance de poissons de l’atlantique." Thesis, Rennes, Agrocampus Ouest, 2017. http://www.theses.fr/2017NSARH100/document.
Full textAbstract:
Les paramètres de croissance de poissons pélagiques et démersaux ont été étudiés durant la période de 1990 à 2015 dans le but d’examiner l’impact de facteurs biotiques comme la densité-dépendance, le recrutement, la mortalité totale et de facteurs abiotiques tels que l’intensité d’upwelling, la température et la concentration en chlorophylle a. Les paramètres d’histoire de vie des espèces peuvent varier selon les espèces, d’une région à l’autre, et dans le temps au sein d’une même région en raison de leur plasticité et de la pression de la pêche. Une comparaison inter-espèces et inter-régions a été réalisée. Le modèle non linéaire à effets mixtes a été utilisé pour différentes populations de l’Océan Atlantique afin d’établir les paramètres de croissance aux niveaux individuel et de la population. Les variations des paramètres de croissance d’une sélection d’espèces ont été mises en corrélation avec des facteurs biotiques et abiotiquesLes espèces (Sardinella aurita, sardinelle ronde, Atherinella brasiliensis, tinicalo, Merlangius merlangus, merlan, Melanogrammus aeglefinus, églefin et Solea solea, sole) montrent des réponses différentes aux facteurs biotiques et abiotiques. Au niveau spatial pour le merlan et l’églefin, la croissance est affectée par la latitude et la température, tandis qu’au niveau temporel la croissance du merlan est affectée par la température et la densité. Il y avait un intérêt pour savoir si les variables morphométriques et le diamètre de l’otolithe de tinicalo étaient de bons indicateurs de la croissance : c’est la longueur standard qui a présentéThe impact of biotic factors such as density-dependent processes, recruitment, total mortality, and abiotic factors such as upwelling intensity, temperature and chlorophyll a concentration on the variation of growth parameters of pelagic and demersal fish were studied during the periods 1990 - 2008 (pelagic) and 1971 - 2015 (demersal). Life history parameters vary according to the species and from one region to another and over time within a given area because of their plasticity and the high fishing pressure. Interspecies and inter-regional comparison were carried out. Non-linear mixed effects models were used on different fish species of the Atlantic Ocean in order to estimate the growth parameters at the individual and population levels. Variations in growth parameters of selected species were correlated with biotic and abiotic factors.Selected species (Sardinella aurita, round sardinella, Xenomelaniris brasiliensis, tinicalo, Merlangus merlangus, whiting, Melanogrammus aeglefinus, haddock and Solea solea, sole) showed different responses to biotic and abiotic factors. Regardind the spatial component for whiting and haddock, the variation of growth parameters was affected by latitude and temperature. Concerning the temporal component, whiting was affected by temperature and density-dependent processes. There was also an interest to know if the morphometric variables and the diameter of the otolith of Atherinella brasilensis were good growth indicators. Among the morphometric parameters examined, the standard length-Age relationship showed the best fit (r2 = 0.90), foll
32
Tomi, Leena Maija. "Studies of otolith-spinal adaptation to altered gravity performed in man." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65511.
Full text
33
黎振航 and Chun-hong Lai. "Postnatal development of otolith neurons in the vestibular nucleus of rats." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31238725.
Full text
34
Sturrock, Anna M. "Environmental and physiological influences on otolith chemistry in a marine fish." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/359373/.
Full textAbstract:
The aim of this project was to determine whether otolith trace dement chemistry can be used [Q track migrations in fully marine fish. This question was addressed through a semi-controlled experiment where Irish Sea and North Sea plaice (Pleurononectes platessa) were maintained in a monitored environment. The relationships between water, blood and otolith chemistry were assessed and with reference to environmental and physiological variables and through comparisons of otolith trace clement chemistry in wild plaice tagged by data storage tags (DST).
35
Akin, Faith W., Courtney D. Hall, Owen D. Murnane, Jennifer Sears, and Richard Atlee. "Impact of Otolith Dysfunction on Postural Stability and Quality of Life." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/2242.
Full textAbstract:
Although otolith organ testing is becoming more widely used in vestibular clinics throughout the world, the clinical significance of otolith organ dysfunction is unclear. The purpose of this study was to determine the impact of otolith dysfunction on postural stability and quality of life. A prospective case-controlled study of Veterans was completed. The findings of this study have important implications for developing effective clinical protocols for the diagnosis and management of individuals with dizziness related to otolith organ dysfunction.
36
Lai, Chun-hong. "Postnatal development of otolith neurons in the vestibular nucleus of rats /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21106186.
Full text
37
Lang, Judy Brenda. "The growth characteristics of sparid otoliths." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1005129.
Full textAbstract:
The periodicity of formation of growth increments in the otoliths of South African sparids was validated by the oxytetracycline labelling technique. Intramuscular injections of oxytetracycline at a dosage of 250mg/kg marked the otoliths of laboratory held juvenile sparids, while a dosage range of 50 - 100mg/kg oxytetracycline, injected intramuscularly, marked adult sparids in the field. Laboratory held, larval sparid otoliths were marked by immersion for 24hrs a solution of 100-150mg/l alizarin complexone. Both daily (microstructural) and annual (macrostructural) growth increments were identified in the otoliths. The micro incremental pattern of deposition in the sparid otoliths conformed to the general pattern of otolith structure. Sparid otoliths consisted of a central opaque nucleus composed of multiple primordia. surrounding this nucleus were daily increments which decreased in width as the distance from the nucleus increased. Both check rings and subdaily increments were visible throughout the otolith. Minor environmental changes did not affect micro incremental deposition. Narrow opaque and wide hyaline annual growth zones were identified in sectioned sparid otoliths. Scanning electron microscope analysis of the annual growth zones revealed that microincrements within the opaque zone were narrowly spaced with prominent discontinuous phases. This resulted in the greater optical density and higher protein content of the zone. The hyaline zone was composed of widely spaced daily increments with prominent incremental phases accounting for the translucent nature of this zone. Opaque zone formation in the otoliths of many South African sparids was found to occur primarily during periods of reproductive activity and was shown to be indicative of slow otolith growth. The hyaline zone was formed after the spawning season, representative of fast otolith growth. The results of this study have resolved much of the controversy surrounding the rate of growth and time of formation of the opaque and hyaline growth zones in South African sparid otoliths.
38
McGrath, Elizabeth Ferreira. "Modeling and Monitoring of Otolith Organ Performance in US Navy Operating Environments." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/27557.
Full textAbstract:
Previous mathematical modeling work has produced a transfer function that relates otoconial layer displacement to stimulus acceleration. Due to the complexity of this transfer function, time domain solutions may be obtained only through numerical methods. In the current work, several approximations are introduced to the transfer function that result in its simplification. This simplified version can be inverted to yield analytic time domain solutions. Results from a frequency response analysis of the simplified transfer function are compared with the same results from the complete transfer function, and with mammalian first-order neuron frequency response data. There is good agreement in the comparisons. Time domain solutions of the approximation are compared to numerical solutions of the full transfer function, and again there is a good match. System time constants are calculated from the simplified transfer function.
A 2-D finite element model of a mammalian utricular macula is presented. Physical dimensions used in the model are taken from mammalian anatomical studies. Values for the material properties of the problem are not readily available; however, ranges are chosen to produce realistic physiologic behavior. Deflections predicted by this model show that a single value for hair bundle stiffness throughout the organ is inadequate for the organ to respond to the entire range of human acceleration perception. Therefore, it is necessary for a range of hair bundle stiffnesses to exist in each organ. Natural frequencies calculated in this model support previous studies on vestibular damage due to low frequency sound.
Divers exposed to high-intensity underwater sound have experienced symptoms attributed to vestibular stimulation. An in-water video-oculography (VOG) system was developed to monitor diversâ eye movements, particularly torsional, during exposure to varying underwater sound signals. The system included an underwater closed-circuit video camera with infrared lights attached to the diverâ s mask with an adjustable mounting bracket. The video image was sent to a surface control room for real-time and post-experiment processing. Six divers at 60 feet in open water received 15 minutes daily cumulative exposure of 240-320 Hertz underwater sound at 160 dB re 1 mPa for 10 days. No spontaneous primary position nystagmus, horizontal, vertical or torsional, was detected in any diver. This experiment was the first successful attempt to record and analyze eye movements underwater.Ph. D.
39
Akin, Faith, and Courtney D. Hall. "Otolith Dysfunction and Postural Stability: A Chronic Effects of Neurotrauma Consortium Study." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/5397.
Full text
40
Mercier, Lény. "Apports de la microchimie pour l'étude des migrations de la Daurade royale (Sparus aurata L.) dans le Golfe du Lion : avancées méthodologiques pour un suivi précis des mouvements mer-lagunes." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20222.
Full textAbstract:
La daurade royale (Sparus aurata, L.) est une espèce migratrice, connue pour coloniser les lagunes côtières, fortement anthropisées, du printemps à l'automne. Identifier les lagunes clés pour l'accomplissement du cycle de vie doit donc permettre de mieux gérer et protéger les populations de daurades du Golfe du Lion. Dans ce cadre, la microchimie de l'otolithe est un outil précieux. Au cours de sa croissance, cette concrétion de l'oreille interne incorpore des éléments chimiques prélevés dans le milieu. Piégés dans le réseau cristallin, ils sont une image des conditions environnementales rencontrées par le poisson à une date donnée ce qui rend possible, en théorie, de reconstituer ses migrations. Néanmoins, pour cela, il faut (i) connaître précisément la croissance du poisson et de ses otolithes, (ii) mettre en évidence des différences chimiques entre les zones clés pour le cycle de vie en identifiant les outils statistiques appropriés pour la discrimination des habitats. Ainsi, (i) la comparaison objective de modèles de croissance, associée à l'analyse d'un spécimen exceptionnellement âgé a permis de remettre en cause les données classiquement acceptées sur la croissance de la daurade et le schéma de croissance de ses otolithes a été établi ; (ii) la comparaison de 4 méthodes statistiques de discrimination a permis de sélectionner la méthode du random forest pour différencier les signatures chimiques des otolithes de S.aurata de différentes lagunes. Ces avancées ont permis de confirmer le schéma migratoire précédemment décrit, tout en révélant une variabilité des comportements entre les individus et au cours de la vie du poisson. Les juvéniles semblent préférer les lagunes dessalées, suggérant un rôle de nurserie pour ces habitats, alors que les adultes préfèrent des lagunes profondes comme l'étang de Thau. Le maintien de la diversité des caractéristiques des différentes lagunes est donc nécessaire, afin d'assurer la pérennité de la population de S.aurata dans le Golfe du LionThe Gilthead seabream (Sparus aurata L.) is a migratory species, known to colonize coastal lagoons with high anthropogenic load, from spring to autumn. It is necessary to identify key lagoons for the seabream life cycle to allow better management and protection of gilthead seabream populations in the Gulf of Lions. For this, otolith microchemistry is a powerful tool. As it grows, this inner ear concretion absorbs chemical elements taken in its surrounding. Traped in the crystal net, these elements are an image of the environmental conditions met by the fish individual. It is then possible to rebuild fish past migrations. For this it is necessary to (i) precisely know the fish and otoliths growth calendars and (ii) identify chemical differences between the key habitats for the life cycle by choosing statistical methods for habitat discrimination.(i) The objective comparison of many growth models, combined to the analysis of an exceptionally old specimen allowed to propose a new scheme for the gilthead seabream growth and its otolith growth pattern was established ; (ii) the comparison of 4 statistical discrimination methods allowed to select the random forest method to differentiate the otolith chemical signatures of gilthead seabreams from various lagoons. These insights confirmed the already described migration pattern and emphasized a behavioural variability between individuals and between periods of life. The juveniles seem to prefer brackish lagoons, suggesting a nursery rôle for these habitats, whereas the adults prefer deeper lagoons as the Thau lagoon. The maintenance of the lagoons diversity is thus necessary for the preservation of the Gilthead seabream population in the Gulf of Lions
41
Alhossaini, Mohsen S. M. H. "Growth and mortality of 0-group plaice, Pleuronectes platessa L., using otolith microstructure." Thesis, Bangor University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352946.
Full text
42
TomaÌs, Javier. "The relationship between otolith growth, structure and composition in temperate marine fish species." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250461.
Full text
43
Beyer, Sabrina G. Szedlmayer Stephen T. "Age determination through shape analysis and validation of otolith annular increments in red snapper, Lutjanus campechanus." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Fisheries_and_Allied_Aquacultures/Thesis/Beyer_Sabrina_2.pdf.
Full text
44
Lai, Chun-hong. "Functional properties of otolith neurons in the vestibular nucleus of young and adult rats during off-vertical axis rotation /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14036460.
Full text
45
Torrado, Mateo Héctor. "De la genómica a la modelización: estudios poblacionales a nivel individual en peces litorales del Mediterráneo occidental." Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/672958.
Full textAbstract:
La conectividad y la adaptación local son dos fuerzas evolutivas contrastantes que influyen en la estructura poblacional. Debido a su complejo ciclo de vida, las especies de peces marinos tienden a estructurarse en metapoblaciones, conectadas casi exclusivamente por movimientos en la fase larvaria. En esta tesis estudiamos la estructura poblacional genómica de varios peces del litoral mediterráneo y los factores potenciales que afectan su distribución. Con este objetivo, combinamos un conjunto de diferentes metodologías que incluyen genómica de poblaciones, lectura de otolitos, modelos de dispersión oceanográfica y teoría de grafos.
Mostramos un efecto negativo de la temperatura sobre la duración de la fase pelágica larval, pero ningún efecto sobre el tamaño del asentamiento, por lo que el aumento de las temperaturas reduciría la capacidad de dispersión de los peces. Con un modelo de dispersión oceanográfica individual, observamos un efecto tanto de la fecha de eclosión como de la duración de la fase pelágica en las distancias y orientaciones de dispersión, pero variable entre especies. Además, encontramos un claro efecto de los frentes oceanográficos en las capacidades de dispersión de nuestras especies, lo que nos permite identificar la presencia de tres unidades hidrodinámicas delimitadas por estos frentes en el Mediterráneo Occidental.
Encontramos una estructura genómica diferente entre las especies simpátricas de Symphodus, a pesar de sus rasgos larvales similares. No obstante, en ambas especies identificamos regiones candidatas para la adaptación local mediante la combinación de análisis de valores atípicos con análisis de asociación ambientales y fenotípicos. Proporcionamos herramientas y pautas para análisis de laboratorio y bioinformáticos para optimizar los estudios utilizando la secuenciación 2b-RAD en diferentes organismos no modelo con diferentes tamaños de genoma. Además, encontramos en tres localidades diferentes tendencias claras de mortalidad selectiva para la fecha de nacimiento y, en menor medida, para la tasa de crecimiento y la duración de las larvas pelágicas en un pez litoral común. Confirmamos estos resultados con un estudio de asociación fenotipo-genotipo, encontrando loci relacionados con estos rasgos, lo que sugiere una base genética para esta mortalidad diferenciada entre colonos y supervivientes. Finalmente, definimos los principales grupos y los principales nodos de conectividad en tres especies de peces en el Mediterráneo Occidental. Con esta información evaluamos el estado de protección de las áreas de alta importancia para el mantenimiento de la conectividad presentes en la zona, encontrando una pequeña proporción de ellas protegidas. En conjunto, estos resultados proporcionan nueva y valiosa información sobre la conectividad, la estructura poblacional y la adaptación en los peces litorales del mar Mediterráneo.Connectivity and local adaptation are two contrasting evolutionary forces influencing population structure. Due to their complex life cycle, marine fish species tend to be structured in metapopulations, connected almost exclusively by movements in the larval phase. In this thesis, we study the population genomic structure of several Mediterranean littoral fishes and the potential factors affecting their distribution. To asses this goal, we combine a set of different methodologies including population genomics, otolith reading, oceanographical dispersion models and graph theory. We show a negative effect of temperature on pelagic larval duration but no effect on settlement size and thus raising temperatures would reduce dispersal capabilities of fishes. With an individual-based oceanographic dispersal model, we observed an effect of both hatching date and pelagic larval duration in the dispersal distances and orientations, but variable among species. Furthermore, we found a clear effect of the oceanographic fronts in dispersal capabilities of our species, allowing us to identify three hydrodynamic units in the Western Mediterranean delimited by these fronts. We found different genomic structuring between sympatric species of Symphodus despite their similar early life traits. Nonetheless, we identified in both species candidate regions for local adaptation by combining outlier analysis with environmental and phenotypic association analyses. We provided tools and guidelines for laboratory and bioinformatics analyses to optimise studies using 2b-RAD sequencing on different non-model organisms with different genome sizes. Additionally, we found in three different localities clear trends of selective mortality for hatch date and lower for growth rate and pelagic larval duration in a common littoral fish. We confirmed these results with a phenotype-genotype association study, finding loci related with these traits, suggesting a genetic basis of differential mortality between settlers and survivors. Finally, we defined the main clusters and the main nodes of connectivity in three fish species in the Western Mediterranean. With this information, we evaluated the protection state of the areas with high importance for connectivity maintenance, finding a small proportion of them protected. All together, these results provide new valuable information about connectivity, population structure and adaptation in littoral fishes of the Mediterranean Sea.
La connectivitat i l’adaptació local són dues forces evolutives contrastants que influeixen en l’estructura poblacional. A causa del seu cicle de vida complex, les espècies de peixos marins tendeixen a estructurar-se en metapoblacions, connectades quasi exclusivament pels moviments en la fase larvària. En aquesta tesi, estudiem l’estructura poblacional genòmica de diversos peixos litorals mediterranis i els possibles factors que afecten la seva distribució. Per avaluar aquest objectiu, combinem un conjunt de metodologies diferents, inclosa la genòmica de la població, la lectura d’otòlits, els models de dispersió oceanogràfica i la teoria de grafs. Mostrem un efecte negatiu de la temperatura sobre la duració de la fase pelàgica larval, però cap efecte sobre la mida de l'assentament. Per tant, l’augment de les temperatures reduiria la capacitat de dispersió dels peixos. Amb un model de dispersió oceanogràfica individual, vam observar un efecte tant de la data d’eclosió com de la duració de la fase pelàgica larval en les distàncies i orientacions de dispersió, però variable entre les espècies. A més a més, vam trobat un clar efecte dels fronts oceanogràfics en la capacitat de dispersió de les nostres espècies, que ens permet identificar la presència de tres unitats hidrodinàmiques al Mediterrani occidental, delimitades per aquests fronts. Trobem estructuracions genòmiques diferents entre espècies simpàtriques de Symphodus, malgrat dels seus trets larvaris similars. No obstant això, vam identificar en ambdues espècies regions candidates a l’adaptació local, combinant anàlisis de valors atípics amb anàlisis d’associacions fenotípiques i ambientals. Vam proporcionar eines i directrius per a anàlisis de laboratori i bioinformàtica per optimitzar estudis mitjançant la tècnica de seqüenciació 2b-RAD en diferents organismes no models amb diferents mides de genoma. A més, hem trobat en tres localitats diferents tendències clares de mortalitat selectiva relacionada en la data d’eclosió i, de forma més feble, relacionada en la taxa de creixement i la durada larvària pelàgica d’un peix litoral comú. Vam confirmar aquests resultats amb un estudi d’associació fenotip-genotip, trobant loci relacionats amb aquests trets, suggerint per tant una base genètica d’aquesta mortalitat diferenciada entre colons i supervivents. Finalment, hem definit els principals grups i els principals nodes de connectivitat de tres espècies de peixos al Mediterrani occidental. Amb aquesta informació, hem avaluat l’estat de protecció de les àrees amb gran importància per al manteniment de la connectivitat, trobant una xicoteta proporció protegida. En conjunt, aquests resultats proporcionen una nova i valuosa informació sobre la connectivitat, estructura poblacional i adaptació en peixos litorals del mar Mediterrani.
46
Maneja, Rommel [Verfasser]. "Influence of ocean acidification on otolith calcification and behavior in fish larvae / Rommel Maneja." Kiel : Universitätsbibliothek Kiel, 2012. http://d-nb.info/1027300405/34.
Full text
47
Shank, Dale. "Evaluating carbon dioxide as a causative agent of otolith crystallization in recirculating aquaculture systems." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1603716784275007.
Full text
48
Price, Eva. "Subjective Visual Vertical and Otolith Compensation: Evaluating Off-Axis Rotation Stimulus in Healthy Controls." Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/honors/448.
Full textAbstract:
The vestibular system senses changes in head position and is responsible for the brain’s perception of verticality. Vestibular dysfunction is caused by deficits in the semicircular canals and/or otolith end-organs with resulting symptoms including dizziness, vertigo, and unsteadiness. Current vestibular rehabilitation focuses on compensation of the semicircular canal-mediated vestibulo-ocular reflex through gaze and balance exercises. Little is known about rehabilitation of otolith organ function, yet research findings suggest that fall risk may be related to otolith dysfunction. A recent case study demonstrated improvement of vertical perception and balance following off-axis rotation in a rotary chair, showing that such stimulation may be useful for compensation of otolith organ dysfunction. The purpose of our research was to further investigate off-axis rotation as a possible treatment method by evaluating subjective visual vertical (SVV) in healthy controls. Two distance parameters (3.5 cm off-axis and 7.0 cm off-axis) were applied to the rotary chair, with results measured through the SVV test, visual analog scales (VAS), and the balance tilt test (BTT). The magnitude of SVV shift following off-axis rotation was measured in both the 3.5 cm and 7.0 cm off-axis experiments. The greater distance parameter (7.0 cm) did not increase SVV shift magnitude more than the 3.5 cm parameter; yet, resulted in greater symptom intensity as measured through the VAS. These findings led to the conclusion that a distance parameter of 3.5 cm off-axis is optimal for stimulating the otolith organs. This discovery may be helpful in future research utilizing off-axis rotation as a possible treatment method for vestibular patients suffering from otolith dysfunction.
49
Mahé, Kélig. "Sources de variation de la forme des otolithes : Implications pour la discrimination des stocks de poissons Identifying blue whiting (Micromesistius poutassou) stock structure in the Northeast Atlantic by otolith shape analysis. Otolith shape as a valuable tool to evaluate the stock structure of swordfish Xiphias gladius in the Indian Ocean Directional bilateral asymmetry in otolith morphology may affect fish stock discrimination based on otolith shape analysis Do environmental conditions (temperature and food composition) affect otolith shape during fish early-juvenile phase? An experimental approach applied to European Seabass (Dicentrarchus labrax)." Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0539.
Full textAbstract:
L’évaluation et la gestion des populations de poissons se basent sur l'utilisation d’unités de gestion appelées « stocks halieutiques ». Pour discriminer ces stocks, la forme des otolithes, pièces calcifiées de l’oreille interne des poissons, peut être utilisée. Dans ce contexte, cette thèse s'est consacrée premièrement à l’étude de la variabilité spatio-temporelle de la forme des otolithes chez 3 espèces de poissons présentant des caractéristiques écologiques (taille, vitesse de nage, comportement dans la colonne d’eau, etc.) et des environnements biogéographiques différents. Les résultats montrent qu’il existe un gradient structurel décroissant de taille des stocks allant des espèces de grands pélagiques aux espèces démersales. Ceci est lié au fait que certaines espèces démersales comme la bogue (Boops boops) sont contraintes par la présence de barrières géographiques et de fronts hydrologiques ce qui n’est pas le cas chez les espèces pélagiques analysées (merlan bleu, Micromesistius poutassou ; Espadon, Xiphias gladius). Dans un deuxième temps, nous avons testé les effets de facteurs confondants potentiels (e.g. l’asymétrie bilatérale directionnelle, AD) sur le pouvoir discriminant de la forme des otolithes. Ainsi, nous avons montré qu'il existe chez la bogue une AD, induite par un processus de latéralisation et qui varie en amplitude et en direction selon la zone géographique étudiée. Chez la bogue, cette AD impacte les résultats d’identification des stocks par la forme qui changent en fonction de l'otolithe, droit ou gauche, utilisé. Si la forme de l’otolithe est utilisée pour discriminer les stocks halieutiques, c’est parce qu’elle reflète en particulier les conditions environnementales qu’a subi le poisson au cours de sa vie. Ainsi, dans la troisième partie de la thèse, nous avons analysé, en conditions contrôlées, les effets de la température et du taux d'acides gras polyinsaturés omega-3 (n-3 AGPI) contenus dans l’alimentation sur la morphogenèse des otolithes de bars (Dicentrachus labrax). Après la naissance, deux étapes peuvent être distinguées dans l’ontogenèse de la forme de l’otolithe avec en premier lieu un allongement qui traduit une croissance moins rapide de l’axe dorso-ventral par rapport à l’axe antéro-postérieur. Il s'en suit des modifications plus localisées avec en particulier une complexification de la zone comprise entre le rostre et l’anti-rostre a priori essentiellement liée au facteur thermique. A l’inverse, le taux de n-3 AGPI ne semble pas influencer la morphogenèse de l’otolithe. L’utilisation des degrés-jours de croissance (GDD) a permis de montrer que l’effet de la température est bien d’accélérer la morphogenèse, mais aussi de changer sa trajectoire: à valeur de GDD fixe, pour 2 températures données, les formes diffèrent. L’ensemble des résultats acquis lors de cette thèse valident l’utilisation de la forme des otolithes pour discriminer les stocks de poissons, mais souligne également le besoin de connaître précisément les sources de la variabilité morphologique des otolithes intra-stock pour pouvoir déterminer plus précisément les limites des stocks halieutiquesThe assessment and management of fish populations is based on the use of management units called fish stocks. The shape of otoliths, calcified structures of the fish's inner ear, can be used to discriminate these stocks. First, this thesis focuses on the study of the spatio-temporal variability of the otolith’s shape for three fish species with different ecological characteristics (size, swimming speed, behaviour in the water column, etc.) and biogeographical environments. The results showed that there is a decreasing structural gradient across stock sizes from large pelagic species to more localised demersal species. This is linked to the fact that some demersal species such as the bogue (Boops boops) are constrained by the presence of geographical barriers and hydrological fronts, which is not the case for the analysed pelagic species (blue whiting, Micromesistius poutassou; swordfish, Xiphias gladius). Secondly, we tested the effects of potential confounding factors (e. g. bilateral directional asymmetry, DA) on the discriminating power of an otolith’s shape. We have shown that there is a DA for bogue, induced by the lateralisation process, which varies in amplitude and direction according to the geographical area. In the bogue, this DA impacts stock identification by otolith shape, which changes according to which otolith is used (i.e. right or left). Otolith shape is useful to discriminate among fish stocks because it reflects the specific environmental conditions that fish have experienced during their lifetime. Finally, in the third part of the thesis, we analyzed, under controlled conditions, the effects of temperature and the diet content of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on otolith morphogenesis for seabass (Dicentrachus labrax). After emergence, two phases can be distinguished in the ontogenesis of otolith shape with an initial elongation that reflects slower growth of the dorso-ventral axis compared to the antero-posterior axis. This leads to more localized modifications, in particular, in a more complex area between the rostrum and the anti-rostrum, which is clearly linked to the thermal regime. Conversely, the percentage of n-3 PUFAs does not appear to influence otolith morphogenesis. The use of growing degree days (GDD) has shown that the effect of temperature is to accelerate morphogenesis, but also to change its trajectory: at a fixed GDD value, for two given temperatures, the shapes differ. All the results obtained in this thesis validate the use of the otolith shape to discriminate fish stocks, but also emphasize the need to know the precise sources of morphological variability of intra-stock otoliths in order to determine more precisely the limits of fish stocks
50
Lowe, Michael Robert. "Reconstructing the past salinities experienced by a freshwater and marine piscivore in the Mobile-Tensaw River Delta using otolith microchemistry." Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Theses/LOWE_MICHAEL_52.pdf.
Full text