Tesi: "Trachurus trachurus"

1

Naish, Kerry-Ann. "The stock identification of the Cape horse mackerel, Trachurus trachurus capensis (Pisces: Carangidae)". Thesis, Rhodes University, 1990. http://hdl.handle.net/10962/d1005165.

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Three stocks of the Cape horse mackerel, Trachurus trachurus capensis, have been recognised in the ICSEAF convention region off southern Africa (Figure 1) on the basis of catch distribution and biological analyses. They were identified as being off Namibia (ICSEAF Divisions 1 . 3 and 1.4), off the West Coast of South Africa (Div. 1.6) and off the South Coast (Div. 2.1 and 2.2). Recently, speculation as to the accuracy of the classification of the South African populations has arisen. The aim of this study was to determine the number of stocks In Divisions 1.6, 2.1 and 2.2, using methodology which assessed the spatial and temporal nature and the phenotypic and genotypic characteristics of the species. The distribution of horse mackerel was evaluated by studying the trends in catch data and length frequency distributions obtained from the demersal industry during 1986 to 1988 and from the demersal biomass cruises in 1987 and 1988. Adult fish, found in Div. 2.1 and 2.2, probably migrated; during the months in which horse mackerel were expected to spawn, CPUE values were higher over the central Agulhas Bank than in the east of the study region. During the quiescent period, catches and numbers were higher in the latter region. Juvenile horse mackerel were found in the nursery areas utilised by pelagic fish and it is likely that they were transported northward from the Agulhas Bank. A decrease in biomass of individuals in Div. 1.5 indicated a separation between a northern and a southern population. Analyses of the phenotype, or epigenetic characters, of horse mackerel were used as a further test of stock integrity. Monthly samples were drawn from Div. 1.6, 2.1 and 2.2 during May 1988 to June, 1989. Comparisons for the values obtained from growth, length-at-50%-maturity and the season of otolith ring formation from each region showed no significant variation in the phenotype. Morphometric analysis proved inconclusive. Monthly gonadosomatic indices show that fish south of the Orange River share the same spawning season. Reports from the literature show that horse mackerel in the latter region differ from those of northern Namibia in spawning season, age-at-50%-maturity and season of otolith ring formation. The genetic structure of the populations of horse mackerel was evaluated by means of a restriction enzyme analysis of the Mitochondrial DNA of 37 fish collected from Divisions 1.4, 1.5, 1.6, 2.1 and 2.2. Two composite genotypes of horse mackerel were found; one belonging to fish in Div. 1.4 and one to fish in Div. 1.6, 2.1 and 2.2. The genetic distance between the two genotypes, 0.07, was the expected distance between two populations at a subspecies level. Fish in Div. 1.5 consisted of both genotypes and may be a region of mixing between the two populations. The interpretation of results was cautioned; prevlous work has shown that the migration of a small number of individuals between two stocks can be expected to maintain a low variation between the populations. In concluding, it was recommended that the horse mackerel be managed as two stocks, one in Div. 1.3 and 1.4 and one in Div. 1.6, 2.1 and 2.2

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2

Gonzalez, Kother Paola Alejandra. "Atresia in the Chilean Jack Mackerel Trachurus murphyi Nichols, 1920 : implication for reproductive dynamics". Thesis, Brest, 2019. http://www.theses.fr/2019BRES0050.

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Le chinchard, Trachurus murphyi constitue une espèce importante pour la pêcherie dans le sud-est de l'océan Pacifique. Dans cette thèse, la morphologie des ovocytes atrétiques, prévalence et l'intensité de l'atrésie ont été décrits. Les stades d'atrésie identifiés sont les stades alpha, bêta et gamma. Les modèles linéaires généraux ont montré que l’incidence des follicules pot-ovulatoires, la température de surface de la mer et le facteur mois/année, expliquent la prévalence et l'intensité. La dynamique des stades alpha et bêta-atrésie pourrait être considérée comme un indicateur potentiel de toute perturbation de la saison de frai de cette espèce. Cette étude constitue une première évaluation comparative de la fécondité entre les femelles atrétiques et non atrétiques pour cette espèce.La fécondité partielle et la fécondité relative sont inférieures à celles observées chez d’autres espèces de Trachurus. T. murphyi, la base de données transcriptomique (tissus du foie et des ovaires) a été générée. Cette étude a notamment permis d’identifier quelques marqueurs plus spécifiques de l'atrésie comme des protéines de liaison aux acides gras (FABP) et de la follistatine. L'analyse transcriptomique a démontré l'expression de gènes potentiellement associés à une infection par des protozoaires.L’ensemble du foie de T. murphyi est parasité par Goussia cruciata (Apicomplexa).L'abondance du parasite était corrélée négativement à la longueur totale de l'hôte. Une relation potentielle entre l’infection par les protozoaires et l’atrésie ne peut être établie
The Chilean jack mackerel Trachurus murphyi support an important fishery in the South-eastern Pacific Ocean which has declined considerably over time. In this thesis, morphology of atretic oocytes in T. murphyi as well, patterns of prevalence and intensity of atresia were described. The stages of atresia identified were alpha, beta and gamma. General linear models showed that incidence of postovulatory follicles, sea surface temperature and month/year, explain the prevalence and intensity of atresia. Dynamics of alpha and beta-atresia could be considered a potential proxy for any disruption of spawning season and the end of spawning season. This is the first assessment comparing fecundity between atretic and not atretic females.The batch fecundity and relative fecundity were lowest compared with other species of Trachurus. In T. murphyi, the transcriptomic database (liver and ovary tissue) was generated. The results show a set of core potential genes as markers for atresia as fatty acid-binding protein (FABP) genes and follistatin. The transcriptomic analysis demonstrated the expression of genes associated to protozoan infection. All liver of T. murphyi were parasitized by Goussia cruciate (Apicomplexa), the abundance of the parasite was negative correlated with the host total length. A potential relationship between protozoan infection and atresia cannot be established

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3

Borges, Maria de Fatima. "The population biology of horse mackerel (Trachurus trachurus L.) in the North-East Atlantic". Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338366.

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This study investigates the population biology of horse mackerel inhabiting the Northeast Atlantic, their spawning grounds and migrations, and the degree of stock separation, with emphasis on the Southern and Western areas of the European shelf. The investigations involved the use of a wide range of methodologies and techniques, including age determination techniques, tagging experiments, the analysis and evaluation of commercial catch data, egg survey data, bottom trawl survey data, biochemical methods, morphometric methods, survey sampling methodology, and associated statistical analysis. Multivariate analysis of morphometric measurements, indicate that the horse mackerel that spawn on the Portuguese shelf (Southern area) are distinct from those that spawn on the Irish shelf (Western area). A distinction can also be made between the Portuguese horse mackerel and those from the Celtic Sea, English Channel and Northern Bay of Biscay. These findings are further supported by a study of otolith first ring distance, which also indicates that the Western and the North Sea horse mackerel are not significantly different from each other. Growth parameters of horse mackerel from the Western and Southern areas were estimated using length and age data and the resulting growth curves for the two areas are different. This result is primarily due to differences in the growth of the younger fish. In the Southern area the fish grow faster than in the Western area. These results provide evidence for the existence of a separate unit stock of horse mackerel off the Portuguese coast, which is reproductively distinct from other populations in the north-east Atlantic. The results froma study of plasma transferrin polymorphisms did not provide any evidence in support of these findings. The population structure and stock separation of horse mackerel in the north-east Atlantic are described and the implications for future management are discussed

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4

Vaz, Ângela Fernanda Corriça. "Parasitoses provocadas por Kudoa (Myxosporea) e larvas de Anisakidae em Trachurus trachurus em Portugal". Dissertação, Universidade do Porto. Reitoria, 2000. http://hdl.handle.net/10216/9904.

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5

Mapukata, Tembela. "Laboratory studies on the feeding behaviour of juvenile Cape horse mackerel, Trachurus trachurus capensis". Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/6968.

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Bibliography: leaves 78-90.
Laboratory studies were conducted on juvenile horse mackerel to examine feeding selectivity and rates of zooplankton consumption of two size classes of fish. Fish were fed a variety of natural zooplankton assemblages and sequential subsampling of water in the experimental tanks provided estimates of prey concentration. Video observations were used to examine feeding behaviour and to investigate the feeding response of horse mackerel to various food types and prey sizes.

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6

Vaz, Ângela Fernanda Corriça. "Parasitoses provocadas por Kudoa (Myxosporea) e larvas de Anisakidae em Trachurus trachurus em Portugal". Master's thesis, Universidade do Porto. Reitoria, 2000. http://hdl.handle.net/10216/9904.

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7

Gomes, Tiago Alexandre Leandro. "Anisakis spp. : relevância da sua pesquisa e identificação em peixes". Master's thesis, Universidade de Lisboa. Faculdade de Medicina Veterinária, 2014. http://hdl.handle.net/10400.5/7586.

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Dissertação de Mestrado Integrado em Medicina Veterinária
Anisakis spp. é considerado um dos mais importantes perigos parasitários dos produtos da pesca na medida em que é responsável pela anisaquiose. Esta zoonose, cujos efeitos gastrointestinais e alérgicos podem ter graves consequências para o ser humano, ocorre quando peixes ou cefalópodes parasitados são ingeridos crus ou confecionados de forma deficiente. Em consequência da sua omnipresença nas principais famílias de peixes e cefalópodes com interesse comercial, tornou-se imperioso o estabelecimento de criteriosas regulamentações. Para se conhecer melhor a realidade portuguesa neste aspeto foi escolhido o carapau (Trachurus trachurus) para efetuar um estudo de ocorrência, intensidade e abundância parasitárias assim como uma caracterização morfométrica dos parasitas do género Anisakis encontrados. Dos 104 exemplares de peixe provenientes da lota de Peniche foram recolhidas 1 504 larvas tanto das vísceras como do músculo. Foi detetada uma positividade global de 67,31% e a intensidade e abundância médias foram, respetivamente, de 21,48 e 14,46. Das larvas do género Anisakis recolhidas 96,61% correspondiam ao tipo I (sensu Berland, 1961). Atualmente, diversas técnicas moleculares são utilizadas na identificação das distintas espécies deste género parasitário como forma de caracterizar mais rigorosamente a sua ecologia e obter dados epidemiológicos mais precisos que resultem na prevenção mais eficaz desta zoonose.
ABSTRACT - Anisakis spp. is considered one of the most important parasitic hazards in fishery products. Being responsible for the zoonosis named anisakiasis, this nematode can cause severe gastrointestinal and allergic effects on consumers when seafood is ingested raw or undercooked. Additionally, it infects most families of commercially relevant fish and squid, generating the urge to regulate this sector through thorough legislation. In order to further understand the situation in Portugal, it was chosen the Atlantic horse mackerel (Trachurus trachurus) to study some aspects of its relationship with the genus Anisakis in terms of parasitic frequency, intensity and abundance as well as to execute a morphometric analysis of the larvae found. Of the 104 fish specimens collected in Peniche, 67.31% harboured a total of 1 504 anisakids both in the viscera and muscle. Mean intensity and abundance were 21.48 and 14.46 (respectively) whereas Anisakis type I larvae (sensu Berland, 1961) represented 96.61% of the total number of worms analized. Currently several molecular techniques are performed to identify the different species integrated in this genus as a way to more accurately characterize their ecology as well as to obtain more exact epidemiologic data in order to prevent this zoonosis more effectively.

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8

Lopes, Patrícia Pereira. "Anisakidae e Raphidascarididae : pesquisa, identificação morfológica e molecular em carapau (Trachurus trachurus) capturado em águas portuguesas". Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2018. http://hdl.handle.net/10400.5/16696.

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Dissertação de Mestrado Integrado em Medicina Veterinária
As larvas de terceiro estádio (L3) das famílias Anisakidae e Raphidascarididae são parasitas com potencial zoonótico que são encontrados com muita frequência nas vísceras e musculatura de vários peixes. Como tal, é crucial o conhecimento sobre a prevalência e a distribuição destes parasitas nos peixes com importância comercial, assim como efetuar uma identificação precisa das espécies de anisaquídeos presentes, pois cada espécie tem um diferente grau de patogenicidade para a saúde humana e animal. Existem já vários estudos publicados em revistas com revisão por pares onde é realizada a identificação genética de vários anisaquídeos encontrados em peixes capturados em águas portuguesas. Contudo, que seja do conhecimento dos autores do presente trabalho, este é o primeiro estudo nacional que correlaciona morfometria com análise molecular subsequente das mesmas L3 de A. simplex (s.s.) e A. pegreffii. Uma vez que estas duas espécies são as mais frequentemente associadas a casos humanos de doença e, embora a identificação com recurso a técnicas moleculares seja o ideal, nem sempre é possível executar esse tipo de técnicas, motivo pelo qual neste trabalho se conjuga as duas técnicas de forma a contribuir para que a distinção com base em características morfológicas seja mais fácil. No presente estudo, 116 carapaus (Trachurus trachurus) capturados em águas portuguesas foram analisados quanto à presença de L3 de anisaquídeos, tendo sido colhidas no total 3148 larvas. Dentro desse total de L3 obtidas, apenas 30% foram colhidas durante a inspeção visual dos peixes, o que demonstra que esse método é pouco eficaz na deteção destes parasitas. Foi encontrada uma prevalência de 84,5% de peixes infetados e a intensidade e abundância média foram, respetivamente, de 32,1 e 27,1 parasitas por hospedeiro. A caraterização morfológica e identificação molecular de 196 L3 escolhidas aleatoricamente a partir da amostra total de parasitas revelou a presença de apenas uma L3 de Hysterothylacium aduncum, sendo as restantes L3 de Anisakis spp. Obteve-se uma frequência relativa de 62,9% de A. pegreffii e 37,1% de A. simplex (s.s.). Entre estas duas espécies crípticas, os resultados da análise da morfometria revelaram que existem diferenças significativas entre o comprimento do ventrículo e o comprimento do esófago, podendo estas medidas ser utilizadas para distinguir ambas as espécies na análise morfológica.
ABSTRACT - Anisakidae and Raphidascarididae: A morphological and molecular survey in horse mackerel (Trachurus trachurus) caught in Portuguese waters - Third stage larvae (L3) of the Anisakidae and Raphidascarididae families are parasites with zoonotic potential which are very frequently found in the viscera and musculature of several fishes. Consequently, it is crucial to know the prevalence and distribution of these parasites in fish of commercial importance, as well as perform an accurate identification of the species of anisakids that are present since each species has a different degree of pathogenicity for human and animal health. Several studies have already been published in peer review journals where genetic identification of many species of anisakids found in fish caught in Portuguese waters was carried out. However, to the extent of the authors' knowledge of the current work, this is the first national study which correlates morphometry with a subsequent molecular analysis of the same L3 of A. simplex (s.s.) and A. pegreffii larvae. Since these two species are the most frequently linked species to the human disease and, although genetic identification is better, it is not always possible to perform this kind of technique, this research conjugated both techniques, in order to contribute for easier distinction by morphological characteristics. In the present study, 116 horse mackerel (Trachurus trachurus) caught in Portuguese waters were analyzed for the presence of L3 of anisakids, and 3148 larvae were collected. Within that total of retrieved L3, only 30% have been collected during the visual inspection of fish, which shows that is not a very effective method for detecting these parasites. A prevalence of 84,5% of infected fish was observed and the mean intensity and mean abundance were, respectively, 32,1 and 27,1 parasites per fish. The morphological characterization and molecular identification of 196 L3 randomly chosen from the total sample of parasites revealed the presence of just one L3 of Hysterothylacium aduncum, with the remaining being L3 of Anisakis spp. A relative frequency of 62,9% of A. pegreffii and 37,1% of A. simplex (s.s.) was obtained. Between these two sibling species, morphometry analysis results revealed that there are significant differences between the length of the ventricle and the length of the oesophagus, and as such these measurements can be used to distinguish both species in the morphological analysis.
N/A

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9

Campbell, Neil. "Population studies of horse mackerel (Trachurus trachurus (L.)) and herring (Clupea harengus L.) using parasites as biological tags". Thesis, University of Aberdeen, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446199.

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Recently, questions have been raised as to the appropriateness of stock boundaries in the Atlantic horse mackerel (Trachurus trachurus) and the herring (Clupea harengus) in European waters. To this end, 1919 horse mackerel were examined for parasitic infections from samples taken at nineteen sites around Europe. Forty-five species of parasites were recorded, eleven of which are new host records, and one may be a new species. A number of these are suitable for use as biological tags. Results showed a significant degree of separation between fish from the North Sea and Western stocks, based on the relative abundance of the nematodes Aniaskis spp. and Hysterothylacium sp. The endoparasitic fauna of 4033 herring at various life stages from sites to the west of the British Isles, the North Sea, Baltic Sea and northern Norway were examined to obtain information on stock identity, mixing and recruitment patterns in these areas. Results revealed that substantial stock mixing takes place to the west of the British Isles, with fish from a wide area being found together in non-spawning aggregations off the Hebrides. This area is also home at different times of year to two different spawning populations of fish which recruit from nursery grounds in the eastern North Sea and from the west of Scotland. Investigations were made of the usefulness of the ribosomal small sub-unit cytochrome oxidase (I) gene of the parasitic nematode worm, Anisakis simplex s.s., as a tag of host population biology. Results revealed the COI gene to be highly variable, with around 50% of worms sequenced having unique haplotypes. There were no population structures evident from analysis of genetic distances.

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10

Testi, Silvia <1967&gt. "Caratteristiche merceologiche, nutrizionali, sensoriali e di freschezza di Nasello (Merluccius merluccius), Lanzardo (Scomber japonicus) e Suro (Trachurus trachurus)". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/1060/.

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Three finfish species frequently caught in the waters of the Gulf of Manfredonia (Apulia, Italy) were studied in order to know how the flesh composition (proximate, fatty acid, macro- and micro- element contents) could be affected by the season effect. The species we examined were European hake (Merluccius merluccius), chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus), which were analysed at the raw state in three catch season and after cooking in two catch season. More precisely, European hake and chub mackerel caught during winter, summer and fall were analysed at the raw state. The composition of the flesh of grilled European hake and chub mackerel was study on fish caught in winter and fall. Horse mackerel of summer and winter catches were analysed both at the raw and grilled state. Furthermore, an overall sensory profile was outlined for each species in two catch season and the relevant spider web diagrams compared. On the whole, two hundred and eighty fish were analysed during this research project in order to obtain a nutritional profile of the three species. One hundred and fifty was the overall number of specimens used to create complete sensory profiles and compare them among the species. The three finfish species proved to be quite interesting for their proximate, fatty acids, macro- and micro-element contents. Nutritional and sensory changes occurred as seasons elapsed for chub and horse mackerel only. A high variability of flesh composition seemed to characterise these two species. European hake confirmed its mild sensory profile and good nutritional characteristics, which were not affected by any season effect.

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11

Verrez, Véronique. "Surimi de chinchard, Trachurus trachurus L. influence de conditions technologiques sur des caractéristiques de texture du produit après traitement thermique /". Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37610794p.

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12

Eymard, Sylvie. "Mise en évidence et suivi de l'oxydation des lipides au cours de la conservation et de la transformation du chinchard (Trachurus trachurus) : choix des procédés". Nantes, 2003. http://www.theses.fr/2003NANT2050.

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Les étapes critiques du procédé de fabrication du surimi de chinchards (Trachurus trachurus) ont été identifiées. Ainsi, des solutions techniques et chimiques ont été proposées afin de limiter le développement des réactions d'oxydation des lipides au cours du procédé. Pour ce faire, les méthodes d'analyse des lipides et de leur produits d'oxydation ont été adaptées aux produits étudiés, une méthode de dosage des hydroperoxydes a été mise au point et la technique de fluorescence en mode frontal testée pour évaluer l'altération du surimi. Les cinétiques d'oxydation des lipides ont été déterminées au cours de la conservation des chinchards sous glace ou à 17ʿC. La formation des composés d'oxydation des lipides a été suivie au cours de la fabrication du surimi et de sa conservation à l'état congelé. L'impact de l'état de fraîcheur de la matière première sur l'évolution des réactions d'oxydation des lipides au cours de la fabrication et de la conservation du surimi a également été déterminé
Critical steps of the process of horse mackerel surimi manufacturing were identified. This led to propose technical and chemical solutions in order to limit development of lipid oxidation reactions. In this way, analytical methods of lipids and lipid oxidation compounds were adapted to the studied products. A method to determine hydroperoxyde concentrations was developed. The front face fluorescence technique was tested to evaluate the degree of surimi alteration. Lipid oxidation kinetics were determined during horse mackerel storage on ice or at 17ʿC. The formation of lipid oxidation products was followed during manufacturing and horse mackerel surimi frozen storage. The impact of raw material freshness on the development of lipid oxidation during surimi manufacturing and storage was also determined

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13

Henriques, Catarina Vieira Lisboa Vendrell. "Aplicação do método de produção diária de ovos ao carapau: (Trachurus trachurus L., 1758). Recuperação de séries de dados obtidos por diferentes estratégias de amostragem". Master's thesis, FCT - UNL, 2009. http://hdl.handle.net/10362/2029.

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Dissertação de Tese apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Ecologia,Gestão e Modelação dos Recursos Marinhos
O carapau, Trachurus trachurus, é um recurso pesqueiro de grande interesse comercial. A monitorização da biomassa da população é imprescindível para a gestão racional do recurso. Um dos métodos de avaliação empregue é o Método de Produção de Ovos, que permite estimar a biomassa desovante de um manancial de peixes com ovos pelágicos a partir da abundância dos produtos da desova. Desde 1986 que o Método de Produção Anual de Ovos(MPAO) tem sido utilizado no Atlântico Norte na estimação deste recurso, sendo apenas a partir de 1992 realizado por Portugal e Espanha. Tendo-se recentemente verificado que esta é uma espécie com fecundidade indeterminada, o Método de Produção Diária de Ovos (MPDO)é aquele que deve ser aplicado. Dada a existência de uma série temporal de amostras de ictioplâncton de 5 anos, a partir de amostragens realizadas segundo ambos os métodos, é imperioso a recuperação dos dados numa perspectiva da aplicação desta última metodologia. Este trabalho pretende reconstituir, tanto quanto possível, uma série de estimativas de produção diária de ovos de carapau, dados obtidos a partir de cinco campanhas de ictioplâncton, realizadas ao longo da costa portuguesa, durante o mês de Janeiro nos anos 1998, 1999, 2001, 2002 e 2004. A Produção Diária de Ovos é estimada com base no modelo exponencial de mortalidade que se representa pela curva de abundância de ovos por idade, presente na área de desova. Uma nova escala de classificação do desenvolvimento embrionário foi estabelecida e experiências de incubação dos ovos a diferentes temperaturas foram realizadas. Desta forma possibilita a atribuição de idades aos ovos, aplicando o Método de Kimura e Chikuni (1987),já que não foi possível corresponder uma hora inequívoca relativa ao pico de desova para esta espécie. Foram obtidas as seguintes produções diárias, em número ovos/m2: 5,211 (1998); 27,312 (1999); 5,759 (2001); 26,828 (2002) e 5,872 (2004). Daqui resulta nas seguintes produções totais, respectivamente, 265,08109; 1104,0109; 57,71109; 867,572109; 308,154109 ovos/m2.

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Le, Roux Jessica Louise. "Parasite assemblages of Cape horse mackerel (Trachurus capensis Castelnau, 1861) from the northern and southern Benguela". Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/6673.

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A survey of parasites infecting Cape horse mackerel, Trachurus capensis Castelnau, 1861, from both the southern and northern Benguela ecosystems was conducted to test the hypothesis of discrete stocks in each subsystem. One hundred and twenty five T. capensis of two size classes were collected off the coasts of South Africa and Namibia and their bodies and organs were examined for parasitic infections. Differences in parasite assemblages between smaller and larger T. capensis within each subsystem, between T. capensis of each size class from the two subsystems, and between larger fish collected in different seasons within the southern Benguela, were assessed. A total of twenty-nine parasite species were found infecting T. capensis. Ten of these were identified to species level (Ceratomyxa australis, Davisia donecae, Ectenurus lepidus, Gastrocotyle trachuri, Goussia cruciata, Lernanthropus trachuri, Nybelinia lingualis, Rhadinorhynchus cadenati, Scolex pleronectis and Tergestia laticollis), three to genus level (Anisakis sp., Caligus sp. and Kudoa sp.). Significant spatial differences in T. capensis parasites were observed, with larger fish differing in infection intensity and abundance of Anisakis sp. and infection intensity of L. trachuri. Significant spatial variation in parasites was also observed in smaller fish, which differed in Anisakis sp. abundance, L. trachuri infection intensity and abundance, G. trachuri abundance and G. cruciata infection intensity and abundance. Significant fish size effects on T. capensis parasites were also observed in both subsystems. Anisakis sp. infection intensity and abundance and G. cruciata abundance differed significantly between larger and smaller fish from the southern Benguela. Larger and smaller fish from the northern Benguela differed in G. cruciata infection intensity and abundance, G. trachuri abundance and L. trachuri abundance. No seasonal differences in parasites of larger T. capensis from the southern Benguela were observed. By using a discriminant function analysis parasite abundance data correctly assigned 92% of larger fish and 96% of smaller fish to their respective southern and northern Benguela sub-populations or stocks. These results show that analyses of parasites can be used to infer population structure and support the hypothesis of distinct T. capensis stocks in the northern and southern Benguela subsystems.

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15

Reed, Jodie Romay. "Bycatch in the South African midwater trawl fishery for horse mackerel (Trachurus capensis) as established from observer records". Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/19999.

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The South African midwater trawl fishery targets adult horse mackerel (Trachurus capensis) on the Agulhas Bank. The bulk of the catch is taken by a single midwater trawler. The bycatch of this fishery is investigated by analysing observer records from 2004 to 2014 to report on bycatch composition, volumes and temporal and spatial patterns. Small fauna were analysed by extrapolation of sample weights and large fauna were counted. The midwater trawl fishery was estimated to have caught 25 415 t annually, with a bycatch rate of 6.9% of the total catch, by weight. Bycatch species with the highest average annual catches were chub mackerel (Scomber japonicus), redeye roundherring (Etrumeus whiteheadi), ribbonfish (Lepidopus caudatus) and hake (Merluccius spp.). Large fauna bycatch species included Cape fur seals (Arctocephalus pusillus), sharks (15 species), sunfish (Mola mola) and cetaceans (two species). Temporal analysis revealed significant differences between day-time and night-time CPUE for nine species, and significant differences in seasonal CPUE for 17 species. Spatial analysis of small fauna species composition and of large fauna species composition identified three groups in each. The 100% observer coverage is high compared to other South African fisheries, and, although the average sampling rate of 1.56% is low, an increase in the sampling rate might not be feasible owing to the size of catches. The bycatch rate in this fishery is low compared to other South African trawl fisheries but similar to global midwater trawl bycatch rates. There are species overlaps with various fisheries, namely the demersal trawl, small pelagic, linefishery, shark longline and squid fisheries, yet the total catch estimates from this fishery are generally small relative to catches taken in the target fisheries.

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16

Mc, Laverty Kathryn J. "A re-evaluation of the life history strategy of Cape horse mackerel, Trachurus capensis in the southern Benguela". Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/12101.

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Includes abstract.
Includes bibliographical references.
The life history strategy of the Cape horse mackerel, Trachurus capensis in the southern Benguela, relating to distribution and reproductive ecology, was re-evaluated. It is possible that certain aspects of the species' life history may have changed since the previous assessment by Barange et al. (1998), as a result in this study, the conceptual hypotheses about the life history of horse mackerel proposed by Barange et al. (1998) were re-evaluated and possible revisions proposed. Distribution patterns were analysed using acoustic and midwater trawl data (1997-2010), and demersal trawl data (1984-2011) collected during biannual surveys of pelagic and demersal fish.

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17

Espinoza, López Ericka Marylin. "Cambios en la distribución espacial de las capturas del jurel (Trachurus murphyi) en el mar peruano entre 1996 y 2007". Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2018. https://hdl.handle.net/20.500.12672/10047.

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Identifica y describe los cambios espacio - temporal de las capturas del jurel en el mar peruano y explorar la relación de las mismas con las masas de agua. Se utilizó datos de capturas georreferenciadas de la flota de cerco industrial entre 1996 y 2007, obtenidas por el Programa de Bitácoras de Pesca - IMARPE. A partir de ellos se analizó a una escala anual, estacional y diaria el comportamiento de las capturas y esfuerzo pesquero mediante análisis de tendencia central y mapeos. Se estimaron los índices espaciales centros de gravedad e inercia espacial de las capturas. Los resultados de los centros de gravedad de las capturas mostraron un cambio latitudinal significativo de norte a sur de las zonas de pesca. Esto marcó dos escenarios espaciales de las capturas, teniendo como punto de quiebre el año 2002. El primero de ellos (1996 – 2001) concentró la pesca en la región Norte, con capturas promedios por lance de 54.5t; y el segundo (2002 – 2007) en la región Centro Sur, con capturas promedios por lance de 60.2 t. Asociado al cambio latitudinal, el tiempo de búsqueda del recurso y número de lances incrementaron hacia el escenario 2. Esto significó un mayor esfuerzo para encontrar y capturar jurel frente a la región Centro - Sur, reflejado en el incremento promedio de 10.8 a 23.8 horas en la búsqueda de cardúmenes y de 3.8 a 6.8 lances por viaje. No se identificó un patrón definido entre años de eventos cálidos (El Niño) o fríos (La Niña) y la distribución de las capturas, aunque hubo diferencias importantes respecto al antes, durante y después del desarrollo de un evento cálido de magnitud moderada a más. Por distancia a la costa, en años cálidos las capturas se concentraron y ubicaron más próximas a costa y en años fríos se dispersaron y alejaron de costa. La interacción masas de agua – capturas del jurel, indicarían que la disponibilidad del jurel hacia la flota fue independiente del tipo de masas de agua, ya que zonas de mayor o menor pesca en términos de presencia (% lances de pesca con jurel) y CPUE (t/lance-vje) no fueron exclusivas a un tipo de masas de agua. El cambio latitudinal de las zonas de pesca del jurel, asociado a la búsqueda de mejores concentraciones del recurso, se explicaría a los cambios en la distribución, abundancia y disponibilidad que ha venido experimentando el jurel durante las últimas décadas, probablemente determinado por las fluctuaciones de las condiciones oceanográficas, lo cual ha repercutido en su disponibilidad hacia la pesca y magnitud de sus desembarques en el mar peruano.
Tesis

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18

Bowker, Jenna. "Parasites of Kunene horse mackerel Trachurus trecae (Smith-Vaniz, 1986) with a comparison of parasites of Cape horse mackerel T. capensis (Castelnau, 1861) in the northern Benguela". Bachelor's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/7629.

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Two species of horse mackerel (Trachurus trecae and Trachurus capensis) reside in the northern Benguela ecosystem. Both are important economic commodities for the Angolan and Namibian fisheries and therefore need to be managed appropriately. Although the two species of horse mackerel share similar morphological characteristics and co-occur in Namibian waters in the northern Benguela, few studies have compared their parasite assemblages. To date there are no studies regarding the parasite profile of T. trecae. This study is the first to identify and document the parasite assemblage of T. trecae from the northern Benguela and forms the only parasite profile for this horse mackerel species. This study also assesses the effects of fish size and fish sex on the parasite assemblage of T. trecae, and compares the parasite assemblage of this species with that of T. capensis from the northern Benguela. Results indicate that the largest significant difference in parasite assemblage is between the two horse mackerel species (by convention p<0.01), but that significant differences are also found between small and large T. trecae and between immature, male and female T. trecae. The coccidian Goussia cruciata was found to have the strongest discriminatory power in all comparisons, and therefore serves as a potential indicator parasite or biotag for discriminating between different stocks of T. trecae and between T. trecae and T. capensis in the northern Benguela. Due to the lack of literature regarding the life history of T. trecae it is difficult to assess why there are sex effects on parasites infecting this species, as well as whether the interspecific difference in parasite assemblage is due to environmental conditions or species-specific relationships. Further investigations regarding the life history of T. trecae would assist interpretation of the results obtained here. This study provides a comprehensive knowledge of the parasite assemblages infecting T. trecae and thus lends to possible future studies regarding T. trecae stock structure. It also provides a starting point for conducting studies of the parasite assemblages of other fish in the northern Benguela.

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19

Navarro, Alor Joceline Liliana. "Evaluación de la calidad microbiológica de Trachurus picturatus murphyi “jurel” y Aulacomya ater “choro” comercializados en diferentes mercados de los distritos de San Juan de Lurigancho y San Martín de Porres, Lima - Perú". Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2017. https://hdl.handle.net/20.500.12672/7310.

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Determina la calidad microbiológica de “jurel” y “choro” procedentes de treinta mercados de los distritos de San Juan de Lurigancho y de San Martín de Porres. Para ello, de cada puesto de mercado se toman muestras de “jurel” y “choro”, a las cuales se les realiza el recuento de aerobios mesófilos y recuento de Staphylococcus aureus según la metodología de ICMSF (2000); asimismo, se determina la numeración de Escherichia coli, la detección de Salmonella sp., Vibrio cholerae y Vibrio parahaemolyticus aplicando la metodología descrita en el FDA/BAM. Los resultados indican que el 56% del total de las muestras analizadas son consideradas “No aptas” para consumo humano; además, se observa que el 17% de las muestras de “jurel” y 63% de las muestras de “choro” superan los límites máximos permitidos establecidos para E. coli. Se aisla Salmonella sp. en el 7% de las muestras de “jurel” y el 20% de las muestras de “choro”. V. cholerae y V. parahaemolyticus no son detectadas en ninguna de las muestras analizadas. Se concluye que la mayor parte de las muestras de “choros” se consideran “No aptas” para consumo humano, constituyendo un riesgo para la salud de los consumidores.
Tesis

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Venter, Jacobus Daniel. "Voeding van die Suid-Afrikaanse maasbanker : Trachurus trachurus Linnaeus". Thesis, 2014. http://hdl.handle.net/10210/8930.

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21

Dhimmer, Viren Rasiclal. "Microplastics in gastrointestinal tracts of Trachurus trachurus and Scomber colias from the Portuguese Coastal waters". Master's thesis, 2017. http://hdl.handle.net/10362/30790.

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Plastic and microplastics are ubiquitous in the marine environment, their presence and possible ingestion can lead to harmful consequences in the marine environment and biota. To provide a quantification of microplastics ingested by commercial fish from the Portuguese Coastal waters and public awareness of the potential harm to human health, a total of 164 samples of Trachurus trachurus and Scomber colias were collected from Figueira da Foz and Sesimbra fishing ports. After dissection and evaluation, 67% of the individuals were found to have ingested microplastics. A total of 399 microplastics were registered, with an average (mean  SD) of 3.63 ± 3.16 microplastics per contaminated fish. Fibres and fragments were the type of MP found in fish, fibres were recurrently found among individuals, 79% comparing to 21% of fragments. Fish collected from Figueira da Foz fishing port, comprise 62% of the total MPs detected, and, S. colias, the Atlantic mackerel ingested 54% of the total microplastics. Kruskal Wallis H test were performed to identify significant statistical differences between sampled groups and Spearman correlation to link any possible relationship between biometric parameters and number of microplastics ingested per fish. Intra-species comparisons identified significant differences in the number of fibres ingested and in the gastrointestinal tract weights, while inter-species comparisons revealed differences in the amounts of fibres and fragments ingested among individuals. Slight Spearman correlations were registered between the biometric parameters and the number of fibres and fragments ingested.

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Chang, Ssu-ling, e 張偲鈴. "Processing Optimization on Puffing Anchovy and Trachurus". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/93380107632200656546.

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碩士
國立臺灣海洋大學
食品科學系
102
Anchovy and trachurus can be gun puff-dried to produce seafood flavored ready-to-eat snack foods. Optimization of product quality when puffing anchovy and trachurus was attempted by Response Surface Methodology. Heating time was checked and found to be well correlated to puffing pressure and used instead for the reason of differentiating. Batch heating time and sample weight were two independent variables with various product quality indexes as dependent variable in the study. A simple model of ideal moisture flash was presented to predict moisture content of puffed products. Changes of moisture content versus independent variables were consistent between experimental results and prediction from model. However, discrepancy was present due to non-ideal behavior of water in foods. Expansion ratio and whiteness index (WI) have opposite requirement from puffing condition, i.e. batch heating time (puffing pressure) and sample weight. An optimization by weighing the two variables is proposed under the criteria of sensory evaluation marks. Product degradation by lipid oxidation was found to be negligible and inconsequential. Puffed anchovy is more crispy but some tasted bitterness while all puffed trachurus have crispness scored less than 4, which is textured like shredded dried squid. A perfect instant of aquatic leisure products should have a large degree of expansion ratio, low moisture content, bright colors and positive sensory reference value. Accordingly, puffing anchovy in the heating time 127 s, material weights about 61-89 g; puffing trachurus in the heating time 215 s, material weights about 70-130 g are the higher quality puffing products.

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Ângelo, Ângela Clarisse Figueiredo Pinto. "Contributo para o estudo parasitário do pescado selvagem da costa Atlântica : o caso da Sarda e do Carapau". Master's thesis, 2011. http://hdl.handle.net/10400.3/996.

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Dissertação de Mestrado em Engenharia Zootécnica.
Este trabalho teve como objectivo a avaliação parasitária de duas espécies de peixes de grande importância comercial em Portugal, o carapau (Trachurus trachurus, famíla Carangidae) e a sarda (Scomber scombrus, família Escombridae). Para tal, com origem na lota da Figueira – da – Foz, no período compreendido entre 25 de Fevereiro a 24 de Junho de 2009, examinou-se um total de 38 exemplares, sendo 20 carapaus e 18 sardas. Procedeu-se à necrópsia parasitária destes, que incidiu sobre a pele, opérculos, brânquias e cavidade abdominal. Foram colhidos 1255 parasitas pertencentes a 6 grupos taxonómicos : conoidasídeos, tremátodos monogenéticos e digenéticos, acantocéfalos, nemátodos e crustáceos. Em ambas as espécies, T. trachurus (n=20) e em S. Scombrus (n=18) a prevalência parasitária foi de 100%. Quanto aos taxa mais presentes, constatou-se que no carapau, os nemátodos representaram 100% de prevalência, com uma intensidade parasitária média de 39.7 parasitas, sendo que na sarda, 72.2% estavam parasitadas, com uma intensidade parasitária de 15.8 parasitas. Os conoidasídeos estavam presentes em ambas as espécies de pescado, 85% dos exemplares de carapau e, 94.4% no caso da sarda. Este estudo deu um contributo para o conhecimento dos parasitas e da carga parasitária em T. trachurus e S. scombrus, sendo de realçar a presença de anisakídeos sob a forma larvar com importância em saúde pública.
ABSTRACT: The aim this work was the evaluation of parasitic burden of two fish species of great commercial impotance in Portugal, the horse mackerel (Trachurus trachurus, family Carangidae) and mackerel (Scomber scombris, family Escombridae). The fish was collected from the fish market of Figueira da Foz, during the period from February 25th to June 24th, 2009. Thirty eight samples were examined, 20 horse mackerel and 18 mackerel. We performed the autopsy of these parasites, which focused on the skin, cap, gills and abdominal cavity. 1255 parasites belonging to six taxonomic groups: conoidasidea, monogenetic and digenetic tremotodes, acanthocephala, nematodes and crustaceans were harvested in both spcies. T. trachurus (n=20) and S. scombrus (n=18) had a 100% parasite prevalence. It was found that the horse mackerel, the nematodes accounted for 100% prevalence, with mean parasitic intensity of 39.7 parasites, and for the mackerel, 72.2 were parasitised, with na intensity of infection of 15.8 parasites. Protozoa were present in both species of fish in 85% horse mackerel, and 94.4% for mackerel. This study hás contributed to the knowledge of parasites species and parasite burden, in T. trachurus and S. scombrus, and to highligth the presence of anisakid larval with public health importance.

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Vasconcelos, Joana Patrícia Reis. "Estrutura populacional do Chicharro, Trachurus picturatus do Atlântico Nordeste". Doctoral thesis, 2017. http://hdl.handle.net/10400.13/1502.

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Esta dissertação abordou duas temáticas principais: a identificação da estrutura do stock de chicharro, Trachurus picturatus (Bowdich, 1825), no sul do Atlântico nordeste e o estudo dos parâmetros de história de vida para a população da Madeira. A estrutura do stock de chicharro ainda é desconhecida e para identificar as unidades populacionais, foram selecionadas três áreas, Madeira, Portugal continental e Canárias, e utilizadas várias metodologias: morfologia do contorno do otólito, morfologia do corpo e análise parasitológica. Na primeira, foram analisados 100 otólitos por área, tendo os resultados da análise aos descritores elípticos de Fourier normalizados (NEFDs) revelado diferenças significativas entre as três áreas (classificação geral de 86.3%). Relativamente à morfologia do peixe, a atribuição de espécimes às localizações geográficas em estudo foi classificada corretamente em 80.7% das amostras (K = 0.67). Estes resultados juntamente com o padrão de infeção dos parasitas Anisakis spp., Rhadinorhynchus sp. e Nybelinia sp. confirmaram a distinção de 3 unidades populacionais no sul do Atlântico nordeste. Nos parâmetros de história de vida, a idade foi determinada a partir de 1405 espécimes, colhidos entre 2009 e 2010. A verificação das leituras foi efetuada segundo a análise do incremento marginal e a evolução mensal do tipo de bordo. Os resultados mostraram a existência de dois anéis por ano, tendo sido atribuídos sete grupos de idade (0-6). Não se verificaram diferenças significativas entre sexos nos comprimentos médios à idade e nas curvas de crescimento de von Bertalanffy. Os parâmetros de crescimento estimados foram: L∞ = 27.98 cm, k = 0.266 ano-1 e t0 = -2.713 ano. A relação peso-comprimento estimada para todos os indivíduos foi de Wt = 0.00411Lt3.230. A época de desova estendeu-se de janeiro a abril. A espécie atinge a maturidade sexual no primeiro ano com comprimentos de 17.06 e 17.04 cm para fêmeas e machos respetivamente.
This thesis addressed two main themes: the identification of the stock structure of blue jack mackerel, Trachurus picturatus (Bowdich, 1825), in the South Atlantic Northeast and the study of life history parameters for the Madeira population. The stock structure of blue jack mackerel is still unknown, and to identify the populational units, three areas were selected, Madeira, mainland Portugal and the Canary Islands, and used different methodologies: otolith morphometry, body shape morphometry and parasitological analysis. For the first methodology, 100 otoliths were analysed by area, and the results of the analysis made to elliptical Fourier descriptors (NEFDs) shown significant differences among the three areas (overall rating of 86.3%). Regarding the body shape morphometry, assigning specimens to the geographic locations under study were correctly classified in 80.7% of the samples (K = 0.67). These results along with the pattern of infection of the parasites Anisakis spp., Rhadinorhynchus sp. and Nybelinia sp. pointed to the existence of 3 stocks in the South Atlantic Northeast. In life history parameters, age was determined on 1405 specimens collected between 2009 and 2010. Otolith reading verification was performed according to marginal increment analysis and monthly analysis of otoliths edge type. The results confirmed the presence of two rings per year, being allocated seven age groups (0-6). There was no significant differences between sexes in mean lengths-at-age and in the von Bertalanffy growth curves. The growth parameters estimated were: L∞ = 27.98 cm, k = 0.266 year-1 and t0 = -2.713 year. The length-weight relationships for sexes combined was Wt = 0.00411Lt3.230. The spawning season extended from January to April. The species reaches sexual maturity in the first year (0.69 year, females and males) with total length of 17.06 cm for females and 17.04 cm for males.
ARDITI - Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação, através do Programa RUMOS

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Nunes, Catarina Matos. "Assessment of the seascape suitability along the Iberian Atlantic margin for species exploited by fisheries". Master's thesis, 2021. http://hdl.handle.net/10773/33517.

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One of the most remarkable effects of climate change in marine realm is the shift in the distribution of species. On the other hand, marine ecosystems are also being modified by commercial fisheries (e.g., decline of species with low reproductive rates, alterations in population size structure, habitat loss and decreased habitat quality). Fisheries combined with climate change may cause the redistribution of marine species commercially exploited by fisheries and these changes can cause considerable socio-economic impacts. Therefore, it is crucial to anticipate these changes aiming a sustainable management of marine living resources and food security. The European hake (Merluccius merluccius) is a demersal species while the horse mackerel (Trachurus trachurus) is a pelagic-neritic species, and both are among the most important species commercially exploited in the Northeast Atlantic. In this work, I estimated the habitat suitability along the Iberian Atlantic waters for the European hake and horse mackerel using an ensemble ecological niche model (ENM) approach. Three machine-learning algorithms (Generalized Boosting Model, Random Forest, Maximum Entropy) were selected to estimate the habitat suitability and related uncertainty maps. The predictions of habitat suitability were made for present ocean conditions (2002-2014) and then projected to future scenarios of climate change (RCP 2.6 and 8.5) for the years of 2050 and 2100. The models were fitted using both oceanographic variables (temperature, salinity, and current velocity) and physiographic variables (bathymetry, bathymetric slope, and sea bottom curvature). The variables that most contribute to the model’s predictions were bathymetry, bottom temperature, and salinity for the European hake and bathymetry and salinity for the horse mackerel. Both the ensemble and single models showed high predictive performance, with the ensemble model estimates consistently performing better than the single models. According to the model for the European hake, the most suitable areas were predicted along the continental shelf, especially along the outer edge while the most unsuitable conditions were found in areas off the continental shelf. Moreover, the ENM predicted a decrease on the habitat suitability comparatively to the present conditions for future scenarios of climate change, mainly in the northern and western Iberian Peninsula whilst in the southern areas the habitat suitability is likely to remain constant. These predictions showed high reliability between single models for the most suitable and most unsuitable areas as well as a low uncertainty. For the horse mackerel the most suitable habitat areas were also predicted for the continental shelf and the most unsuitable areas were predicted in offshore area. The projections for the habitat suitability according to future ocean conditions estimated a slightly to moderate increase in the habitat suitability for areas currently offering low habitat suitability for the species. Notwithstanding, these projections were subjected to moderate to high uncertainty. On the other hand, the ensemble prediction for the areas of higher habitat suitability for horse mackerel show low uncertainty. This study brings new insights to the potential impact of climate change in distribution of two economically important species. It is important to be aware that climate change and anthropogenic activities, such as fisheries, will continue to co-exist, putting pressure on the stocks of diverse fish species. Changes in the potential distribution of species may require new management measures for the fishing sector, such as the redefinition of fish stocks and fishing effort. This study provides relevant and spatial explicitly information that may contribute for the development of effective conservative and management measures.
Um dos efeitos mais notáveis das alterações climáticas no ambiente marinho é a mudança na distribuição das espécies. Por outro lado, os ecossistemas marinhos estão também a ser modificados pela pesca comercial (por exemplo, o declínio de espécies com baixas taxas de reprodução, alterações na estrutura da população, perda de e diminuição da qualidade do habitat). A pesca combinada com as alterações climáticas pode causar a redistribuição de espécies marinhas comercialmente exploradas, sendo que estas alterações podem causar impactos socioeconómicos consideráveis. Por conseguinte, é crucial antecipar estas mudanças visando uma gestão sustentável dos recursos marinhos vivos e a segurança alimentar. A pescada europeia (Merluccius merluccius) é uma espécie demersal enquanto o carapau (Trachurus trachurus) é uma espécie pelágico-nerítica, sendo que ambas são consideradas das mais exploradas comercialmente pelo setor pesqueiro no Atlântico Nordeste. Neste trabalho, foi estimada a adequabilidade do habitat ao longo das águas do Atlântico Ibérico para a pescada europeia e para o carapau, utilizando uma abordagem ensemble de modelo de nicho ecológico (ENM). Foram selecionados três algoritmos de machine-learning (Generalized Boosting Model, Random Forest, Maximum Entropy) para estimar a adequabilidade do habitat e mapas de incerteza relacionados. As previsões de adequabilidade do habitat foram feitas para as atuais condições oceânicas (2002-2014) e depois projetadas para cenários futuros de alterações climáticas (RCP 2.6 e 8.5) para os anos de 2050 e 2100. Os modelos foram ajustados usando tanto variáveis oceanográficas (temperatura, salinidade, e velocidade da corrente) como variáveis fisiográficas (batimetria, inclinação batimétrica, e curvatura do fundo do mar). As variáveis que mais contribuíram para as previsões do modelo foram a batimetria, temperatura do fundo e salinidade para a pescada europeia e a batimetria e salinidade para o carapau. Tanto o ensemble como os modelos individuais mostraram um desempenho preditivo elevado, com as estimativas do modelo de ensemble a apresentarem um desempenho consistentemente melhor do que os modelos individuais. De acordo com o modelo para a pescada europeia, as áreas mais adequadas foram previstas ao longo da plataforma continental, especialmente ao longo do limite da plataforma continental, enquanto as condições menos adequadas foram encontradas em áreas fora da plataforma continental. Além disso, o ENM previu uma diminuição da adequabilidade do habitat comparativamente às condições atuais para cenários futuros de alterações climáticas, principalmente no norte e oeste da Península Ibérica, enquanto nas áreas do sul a adequação do habitat estima-se que se mantenha constante. Estas previsões mostraram uma elevada confiança entre modelos únicos para as áreas mais adequadas e mais inapropriadas, correspondendo a uma baixa incerteza. Para o carapau, as áreas de habitat mais adequadas foram também previstas para a plataforma continental e as áreas menos adequadas foram previstas na zona offshore. As projeções para a adequação do habitat de acordo com as futuras condições oceânicas estimaram um ligeiro a moderado aumento na adequabilidade do habitat para áreas que atualmente oferecem uma baixa adequabilidade do habitat para a espécie. Não obstante, estas projeções foram sujeitas a uma incerteza moderada a elevada. Por outro lado, a previsão do ensemble para as áreas de maior adequabilidade de habitat para o carapau, mostra uma baixa incerteza. Este estudo traz novos conhecimentos sobre o impacto potencial das alterações climáticas na distribuição de duas espécies economicamente importantes. É importante estar ciente de que as alterações climáticas e as atividades antropogénicas, tais como a pesca, continuarão a coexistir, exercendo pressão sobre os stocks de diversas espécies de peixes. As alterações na distribuição potencial das espécies podem exigir novas medidas de gestão para o sector das pescas, tais como a redefinição dos stocks de peixe e do esforço de pesca. Este estudo fornece informação relevante e espacialmente explícita que pode contribuir para o desenvolvimento de medidas eficazes de conservação e gestão.
Mestrado em Biologia Marinha Aplicada

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26

Chen, Chih-Chun, e 陳治君. "Age and growth study of the jack mackerel (Trachurus japonicus) in the northeastern waters off Taiwan". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/18627693984099459316.

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碩士
國立臺灣海洋大學
環境生物與漁業科學學系
100
Jack mackerel (Trachurus japonicus) widely distributed from East China Sea and the coastal waters of Japan, Korea, and Taiwan, is an important fishery resource in the northeastern Taiwan. In recent years, rapid developing of Taiwanese seiner fishery, a new fishing gear, the catch and proportion of jack mackerel increased significantly. However, the age and growth parameters for jack mackerel were very old and catch-at-age composition is poorly known. In this study we collected otolith samples from jack mackerel catch (May, 2010 to April, 2011) for age determination. We also included the length and weight data from March, 2009 to January, 2012 to understand catch-at-age of jack mackerel in the northeastern waters off Taiwan. This study has following findings: 1. The relationship between fork length (FL) and body weight (BW) of jack mackerel were significantly different for females and males. The length-weight relationships were BW=3.6×10-2×FL2.6771 for females, and BW=3.2×10-2×FL2.7108 for males. 2. The formations of opaque zones were estimated during January to February and the ring formed once per year. The maximum age observed from the samples was 5 years (FL=32.4 cm) and minimum was 0 year (FL=14.3 cm). The parameters of von Bertalanffy growth function obtained for combined sex was L∞=40.4 cm, k=0.223 yr-1. 3. The major cohorts utilized of jack mackerel in the northeastern waters off Taiwan were 0-age (39%) and 1-age (38%). Most of them were in immature stage. The proportion of catch for 0-age was higher in winter comprising of 42~77%. The proportion of 0-age was low in summer only comprising of 3~10%. The growth of jack mackerel in the northeastern waters off Taiwan was much slower than those in Japan waters. Further study is needed to clarify its relationship with the two stocks in Japan waters. The age composition indicated that the percentage of immature jack mackerel utilized in northeastern Taiwan were considerably high. Meanwhile, the stock abundance of spotted mackerel has being declined for many years. It is recommended to implement adequate closure measures during spawning period and catch restriction to reduce fishing mortality of young fish, which will be helpful for sustainable utilization of mackerel and carangid fish resources in the northeastern waters off Taiwan.

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27

Lin, Chun-Chia, e 林俊嘉. "Study of the Influencing Factors on the Parasitism between Anisakid Nematodes and Horse Mackerel, Trachurus japonicus". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/55040186758514652009.

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Abstract (sommario):

碩士
國立臺灣大學
動物學研究研究所
94
The horse mackerel, Trachurus japonicus, is one of the important fish species of fishery industries in Taiwan. The aim of this study is to investigate its parasitic fauna firstly. Secondly, physiological factors of horse mackerel including Fork Length, Hepasomatic Index, Gonosomatic Index, and Index of Stomach Fullness are calculated. The possible influencing effects of these factors were finally tested against the infection status in these fish. Furthermore, the infracommunity of two genera Anisakis and Hysterothylacium populations inside horse mackerel was highlighted using polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). A total number of 480 individuals of horse mackerel were collected from January, 2005 to April, 2006 in Dasi Fishery Harbor of Yilan County. The main parasite fauna includes Anisakis simplex, Hysterothylacium aduncum, Raphidascaris trichiuri, and Pseudoterranova decipiens belonging to the family Anisakidae. Three digeneans and one cestode were also recorded. The main infection months for family Anisakidae nematodes are from February to July, 2005. The highest abundance appears in the infection of H. aduncum, and A. simplex is in the next place. Significant difference between horse mackerel fork length between total numbers of 4 anisakid species were observed, and also did the abundance of A. simplex (p＜0.01). Significant differences between GSI and the abundances of total 4 anisakids, A. simplex, and H. aduncum were noticed (p＜0.05). In addition, difference between HSI with the abundance of A. simplex was significant (p＜0.01). There was no significant difference between ISF and abundance of the 4-species anisakids, A. simplex or H. aduncum (p＞0.05). The infracommuity of the Anisakis populations inside horse mackerel analysed by PCR-RFLP was composed of 60% of A. typical, 30% of recombinant genotype of A. pegreffii and A. simplex s.s., and 10% of A. pegreffii. The result of RFLP analysis showed only one species, H. adundum, in Hysterothylacium populations.

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28

Baião, Nelson Francisco. "Crescimento, ecologia alimentar e reprodução de Trachurus trecae (Cadenat, 1949), na costa sul de Angola-Namibe". Master's thesis, 2015. http://hdl.handle.net/10400.1/7887.

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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
Neste estudo, o crescimento, ecologia alimentar e reprodução de Trachurus trecae (Cadenat, 1949), capturado na costa sul de Angola (Namibe), foram estudados a partir de dados de capturas comerciais durante o verão austral de 2015 (Janeiro-Abril). As idades foram atribuídas a partir da leitura e interpretação das marcas de crescimentos registadas nos otólitos e os parâmetros de crescimento foram obtidos pela equação de von Bertalanffy para o crescimento em comprimento e em peso. A relação existente entre os bordos dos otólitos e o índice de condição indicou durante o período de amostragem que os maiores valores dos índices de condição (K), coincidiram com a deposição dos bordos opacos e a formação do bordo translúcido coincidiu com os baixos valores do índice de condição. As idades atribuídas variaram entre os 3 e 11 anos, correspondendo à comprimentos e pesos médio à idade de 12 e 36.5 cm e 17g e 411g respetivamente. Método indireto baseado na análise de frequência de comprimento foi usado para comparar os parâmetros de crescimento e validar os dados de idade e tendo em conta os seus parâmetros os resultados mostraram que a espécie Trachurus trecae tem um crescimento rápido. A relação peso-comprimento mostrou que Trachurus trecae tem um crescimento alométrico negativo (b=2.69). A relação linear entre o comprimento dos indivíduos e o comprimento dos otólitos foi calculada. A análise do conteúdo estomacal indicou que os Eufasiáceos, Decápodes, Copépodas “Calanóides”, Sifonostomatóides, Larvas de peixe e peixes foram as principais presas encontradas nos estômagos. Os Eufasiáceos foram as presas principais (Q=224) e os peixes contribuíram com 35% do peso total do conteúdo estomacal. Este estudo indicou que o consumo de alimentos aumentou com o comprimento e o estado de maturação. Os valores calculados dos índices gonadossomático e hepatossomático, mostraram que o desenvolvimento das gónadas para a maturação começou em Janeiro e teve o pico em Março. A análise do estado de maturação das gónadas mostrou que a maioria dos indivíduos foram encontrados nos estágios 2, 3 e 4. Observou-se também que as fêmeas atingem o comprimento da primeira maturação primeiro que o machos (50% = 28 cm e 29.6).

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29

Wu, Ming Zhong, e 吳明忠. "Target strength analyses on alive common mackerel (scomber japonicus) and atlantic horse mackerel (trachurus japonicus) of individuals". Thesis, 1996. http://ndltd.ncl.edu.tw/handle/46009806192131196100.

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30

Liu, Jen-Ming. "Fishery Acoustic Studies on Two Species Gathering of Scomber australasicus and Trachurus japonicus in the Waters off Northeastern Taiwan". 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2907200619534300.

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31

Wu, Shin-Bey, e 吳欣蓓. "A fundamental study on the reproductive biology of the jack mackerel (Trachurus japonius) in the northeastern waters off Taiwan". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/90146689088613970684.

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Abstract (sommario):

碩士
國立臺灣海洋大學
環境生物與漁業科學學系
98
The jack mackerel (Trachurus japonius) is one of the target species for mackerel purse seine fishery in the northern Taiwan, comprising about 5.11% of the total catch. In recent years purse seine fishery is gradually replaced by lampara seiners (also called tiger seine) and the catch of jack mackerel has increased to 26.55%. However, few study was on spawning of jack mackerel which is important factor for its recruitment and stock management. This study is based on 3499 jack mackerel sampled from the seiners of Pa-Tao-Tze and Auti fishing ports from March 2009 to April 2010. Fork length, body weight, gonad weight and liver weight of collected jack mackerel specimens were measured and compiled to study their reproductive conditions. Our findings shown as the following: 1. The relationship between fork length (FL; in centermeter) and body weight (BW; in gram) of jack mackerel were significantly different for females (BW=0.0234×FL2.8127) and males (BW=0.0190×FL2.8764). However, the differences were not significant for those fork length less than 19 cm. 2. The overall length frequencies of jack mackerel from rages for 13.9 to 31.5cm. During the fall, winter and spring months September to April, smaller mackerel with fork length of 13 to 17cm can be found in the fishing ground which may imply recruitments occurred. 3. The chi-square test showed that sex ratio increased gradually while body length invreased and such phenomenon were mor significant more for females. Therefore, sex ratios were significant higher during spawning season and turned low in non-spawning or pre-spawning seasons. 4. According to Gonosomatic Index of female samples and the microscopy of overies, the occurrences of spawning for jack mackerel were estimated during March-April. The 50% matured fork length was 18.9 cm. 5. The Hepatosomatic Index and the Condition Factor showed that the fatness and nutrition were poor in the pre-reproductive stage and gradually increased in the reproductive period, without obvious phenomenon of the energy accumulation. The spawning grounds of Jack mackerel of the local stock were located from waters of Peng-chia Island, southern East China Sea to Guei-shan Island. The nursery grounds were coastal waters of northeastern Taiwan Peng-chia Island and may extended to East China Sea. However, its relationship with the stock spawning and feeding in Kyu-shyu, Japan and East China Sea are still unclear and need to insert further study.

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32

Liu, Jen-Ming, e 劉仁銘. "Fishery Acoustic Studies on Two Species Gathering of Scomber australasicus and Trachurus japonicus in the Waters off Northeastern Taiwan". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/65948793108511756904.

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博士
國立臺灣大學
海洋研究所
94
Scomber australasicus and Trachurus japonicus are the two most abundant species in the waters off northeastern Taiwan and have been utilized by the large-scale purse seine fishery based in NanFanAo fishing port for a long time. For the purpose of sustainable usage of these resources, promptly and precisely providing information on the available biomass of the resources is urgently needed. Fisheries acoustic assessment method is often used to acquire abundance information of underwater organisms, yet mostly on single species gathering. The purpose of this paper is thus to provide acoustic means for assessing a two-species gathering. An algorithm for properly Grouping Anonymous TS (GATS) was proposed for assessing in situ acoustic information echoed from a two-species gathering. Results thus obtained were summarized as follows: After a confirmation on a hammer-shaped appearance of two concentrations of in situ TS versus depth in an elementary distance sampling unit (EDSU), the available EDSUs of only containing S. australasicus and T. japonicus two-species gathering were 82.6% of the total 924 EDSUs. The GATS searching algorithm can successfully provide best fit on its percentage composition of the two-species gathering providing that the TS-FL relationship for each species is given as well as a constant given standard deviation σTS, which is borrowed from the results of repetition ping on an anchored live fish. Four results of percentage composition (w1: w2) of S. australasicus (w1) versus T. japonicus (w2) obtained by using GATS searching algorithm were (0.414 : 0.586), (0.627 : 0.373), (0.931 : 0.069), and (0.586 : 0.414) as compared to the actual percentage composition obtained from species-size survey were (0.41 : 0.59), (0.64 : 0.36), (0.93 : 0.07), and (0.59 : 0.41), respectively. Differences between theoretical best fits versus observed results are very small. A verification process using generated data of known parameters was also carried out for searching the stability of GATS algorithm. The results thus obtained indicate that (1) the minimal size of acquired TS must not smaller than 3000 and (2) recognizable difference in two species’ mean TS must not smaller than 0.03 dB, which is equivalent to 7 cm in size difference. It is thus suggested a proper survey setting comparable with aforementioned conditions is essential for a successful fisheries acoustic assessment. Mean size in fork length (FL) of S. australasicus obtained by fish-size survey carried out at Nanfanao fishing port as compared to the mean size back calculated by using GATS researching algorithm are 29.7 vs 29.2; 30.9 vs 30.8; 31.7 vs 31.6; 27.0 vs 26.3, for surveys on 1995/March, 1996/April, 1997/July, 1998/November, accordingly. Those of T. japonicus are 20.4 vs 20.0; 20.9 vs 21.7; 24.9 vs 24.2; 18.5 vs 18.1, accordingly. Again, the discrepancies between the two are insignificant. For spatial distributions of estimated mean FL and biomass, larger mean FL of S. australasicus concentrated near the edge of slope of the continental shelf with slight biomass but the abundant biomass with smaller size were concentrated at the northwest part of continental shelf and below the slope in May. Mean FLs distribution was divided into two groups two month later. One group of larger size S. australasicus stayed at the northwest area of high latitude, the other of larger size stayed along the slop to bottom of continental shelf. Though one group of mean FLs distribution of larger size was concentrated below the slope, there was an abundant S. australasicus of small size stayed at the northwest area of high latitude. Mean FLs spatial distribution of T. japonicus was much smaller than S. australasicus. The mean FL of T. japonicus was smaller than 24 cm in May. The large size fish appeared to concentrate along the edge of shelf after two month. Spatial biomass distribution of T. japonicus was much homogenous than S. australasicus in May but as the same condition in July, i.e., concentrated below the slope. An obvious result suggested that whatever S. australasicus or T. japonicus of small size stayed at the continental shelf in May but larger size fishes were divided into two groups staying at northwest area of high latitude and slope, respectively. Standing crops, in an area of 14.4 thousand square of nautical mile, of S. australasicus and T. japonicus, were estimated as 1.40x105 tons and 1.30x105 tons, respectively, for the period of 1995-1996. The catch level or removal of these two species from the area in 1995-1996 was about 3.2x104 tons annually by the large-scale purse seine fisheries of Taiwan, which is about 11.8% of their total standing crops.

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33

Costa, Gisela Sofia Correia. "Caracterização e sustentabilidade do sistema socioecológico para a exploração de chicharro (Trachurus picturatus (Bowdich, 1825)) em São Miguel, Açores". Master's thesis, 2021. https://hdl.handle.net/10216/139243.

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34

Li, Ping, e 李屏. "A study on early growth of jack mackerel (Trachurus japonicus) in the northeastern waters off Taiwan by otolith daily growth increments". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/07304613663229612803.

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Abstract (sommario):

碩士
國立臺灣海洋大學
環境生物與漁業科學學系
103
Jack mackerel Trachurus japonicus, widely distributed in the East China Sea and coastal waters of Japan, Korea, and Taiwan, is one of the most important fish resources in the northeastern waters off Taiwan. In recent years, many studies regarding the age, growth and reproduction of jack mackerel has been reported. However, the information of their early life history in the northeastern waters off Taiwan is still unknown. In order to solve the problem, the larval samples collected from different sources in the study area during 2005-2014 were used to determine age information of larval fish. The relationship between body length and daily age of the samples preserved by ethanol solution was established, with which the daily age of the samples preserved by formalin solution. A total of 402 larvae samples were analyzed, with body length from 1.5 to 7.3 mm and the ages were estimated from 0 to 30 days. Gompertz growth equation was used to describe the biological characteristics of age and growth of early life. The results are summarized as follow: (1) The distribution of jack mackerel in the northeastern waters off Taiwan was dominated by small larvae of body length ranged from 3-4 mm, which indicates that northeastern waters off Taiwan were spawning grounds and the nursery grounds for jack mackerel. (2) Initial length of the jack mackerel is 1.47 mm, growth rate of early life stage is 2.30 mm/d, and the decreasing growth rate is 0.04 mm/d. (3) Growing rates of larvae increases significantly from preflexion stage to flexion stage and slows down thereafter. (4) The hatching date distribution estimated by daily rings indicated that jack mackerel tends to spawn at the periods of new moon and half-moon.

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35

Panguila, Eduardo António. "Avaliação da frescura e do tempo de conservação útil da cavala (Scomber spp) e do carapau (Trachurus spp) frescos e refrigerados, comercializados em Faro (Portugal) e em Luanda (Angola)". Master's thesis, 2016. http://hdl.handle.net/10400.1/9819.

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Dissertação de mestrado, Tecnologia de Alimentos, Instituto Superior de Engenharia, Universidade do Algarve, 2016
A cavala (Scomber spp.) e carapau (Trachurus spp.) são espécies ricas em proteínas, ácidos gordos insaturados do tipo ómega-3, vitaminas e sais minerais. Entretanto, a maior procura e consumo destas espécies devido à sua abundância e baixo valor comercial, tem levantado algumas preocupações sobre a sua qualidade e segurança alimentar por parte dos consumidores, nomeadamente em Angola onde informações sobre o controlo de qualidade, bem como o tempo de prateleira das referidas espécies durante o transporte e armazenamento são praticamente inexistentes. Neste trabalho, utilizou-se uma metodologia baseada na análise sensorial (o método do índice de qualidade, ou QIM) e um conjunto de determinações físico-químicas (cor, textura, pH, teor em azoto básico volátil total ou ABVT, índice de peróxidos ou IP, e teor em substâncias reativas ao ácido tiobarbitúrico ou TBARS) para avaliar o grau de frescura/qualidade e estimar o tempo de conservação útil das referidas espécies frescas e refrigeradas, comercializadas em Faro (Portugal) e em Luanda (Angola). Amostras da cavala (n=25) e de carapau (n=27) foram armazenadas e refrigeradas em gelo a 5 °C durante 11-13 dias. Ao sétimo dia de armazenamento, tanto as amostras da cavala como de carapau, foram rejeitadas sensorialmente pelo painel de provadores em Faro e Luanda. Nesse dia, os resultados do teor em ABVT registados nas amostras de cavala (37,57±1,17 mg N/100 g para Faro e 37,34±2,61 mg N/100 g para Luanda) e de carapau (49,12±0,84 mg N/100 g para de Faro e 30,11±3,45 mg N/100g para Luanda), estavam acima do limite máximo (30-35 mg N/100g) referido na regulamentação aplicável. Portanto, com base nestes resultados e nos restantes parâmetros de qualidade avaliados neste trabalho, estima-se um tempo máximo de conservação útil de 7 dias para cavala e carapau comercializados em Faro e Luanda, quando armazenados e refrigerados com gelo a 5 °C.
Mackerel (Scomber spp.) and horse mackerel (Trachurus spp.), are rich in protein, unsaturated fatty acids of the omega-3 type, vitamins and minerals. However, the increased demand for and consumption of these species due to their abundance and low price, has raised some concerns about its quality and food safety for consumers, particularly in Angola where there is little information about the quality control, as well as the shelf time of these species during transport and storage. In this study, a sensory-based methodology (the quality index method QIM) and a set of physic-chemical analyses (viz. determination of colour, texture, pH, content in total volatile basic nitrogen or TVB-N, peroxides index or IP, and content in thiobarbituric acid reactive substances or TBARS), was used to evaluate the degree of freshness and estimate the shelf life fresh, chilled mackerel and horse mackerel marketed in Faro (Portugal) and Luanda (Angola). Samples of mackerel (n=25) and horse mackerel (n=27) stored and chilled with ice at 5 °C, were evaluated for sensory attributes and physicochemical parameters during the 11-13 days storage period. On day 7, samples of both mackerel and horse mackerel were rejected by panellists in Faro and in Luanda. On that day, the TVB-N content in mackerel (37.57 ± 1.17 mg N/100 g to Faro and 37.34 ± 2.61 mg N/100 g for Luanda) and horse mackerel (49.12 ± 0.84 mg N/100 g for Faro and 30.11 ± 3.45 mg N/100 g for Luanda) were above the maximum limit (30-35 mg N/100 g) referred to in the applicable regulation. Thus, based on these results and the other quality parameters assessed in this study, a shelf-life of 7 days is estimated for mackerel and horse mackerel marketed in Faro and Luanda, stored with ice at 5 °C.

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36

Moreira, Cláudia Filipa Devesa André. "Population structure, movement patterns and habitat connectivity of the blue jack mackerel, Trachurus picturatus, in the NE Atlantic: otolith morpho-chemistry, body shape and genetic markers as combined tools for a rational management of fisheries resources". Tese, 2020. https://hdl.handle.net/10216/128629.

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37

Moreira, Cláudia Filipa Devesa André. "Population structure, movement patterns and habitat connectivity of the blue jack mackerel, Trachurus picturatus, in the NE Atlantic: otolith morpho-chemistry, body shape and genetic markers as combined tools for a rational management of fisheries resources". Doctoral thesis, 2020. https://hdl.handle.net/10216/128629.

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