Articles de revues : « M. gigas »

1

Gibbs, M., E. Scanes, L. Parker, M. Byrne, W. O’Connor, P. Virtue et P. Ross. « Larval energetics of the Sydney rock oyster Saccostrea glomerata and Pacific oyster Magallana gigas ». Marine Ecology Progress Series 656 (10 décembre 2020) : 51–64. http://dx.doi.org/10.3354/meps13538.

Texte intégral

Résumé :

Larvae are a critical dispersal stage of marine invertebrates, and their survival depends on nutrition and energetics. This study compared the size, survival, metabolic rate and egg and larval lipid class profiles of larvae of the endemic Sydney rock oyster Saccostrea glomerata and the invasive Pacific oyster Magallana gigas through a period of starvation for 5 and 9 d after fertilisation. Starved larvae grew without food until 5 d of age, at which point they stopped developing, but resumed growth when fed. Egg lipids profiles comprised 78.1 and 74.5% triacylglycerol for M. gigas and S. glomerata respectively. When fed, larvae of M. gigas were significantly larger in size and had faster growth and similar survival compared to S. glomerata. When starved, larvae of M. gigas and S. glomerata grew at similar rates, and there was a trend for lower survival of M. gigas. Larval endogenous lipid reserves were deleted in the first 24 h. Larvae of M. gigas had more total lipids and comparatively more diacylglycerols, monoacylglycerols, phospholipids and cholesterol, whereas S. glomerata had more diacylglycerols and produced sterol esters. Starvation altered the patterns of lipid assimilation, and metabolic rates of larvae of M. gigas and S. glomerata differed over time. When starved, S. glomerata larvae had greater capacity to cope with starvation compared to M. gigas, perhaps due to an evolutionary history in oligotrophic estuaries. As the climate rapidly changes in this global climate-change hotspot, S. glomerata is likely to be negatively affected.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Ezgeta-Balić, Daria, Tanja Šegvić-Bubić, Elizabeta Briski, Leon Grubišić, Dubravka Bojanić Varezić, Yaping Lin et Nika Stagličić. « Rasprostranjenost nezavičajne vrste kamenice Magallana gigas(Thunberg, 1793) duž istočne obale Jadrana ». Acta Adriatica 60, n^o 2 (27 décembre 2019) : 137–46. http://dx.doi.org/10.32582/aa.60.2.3.

Texte intégral

Résumé :

Non-native Pacific oyster Magallana gigas (Thunberg, 1793) was introduced to the Mediter-ranean Sea for aquaculture purposes in the 1960s. Although this species was not introduced for aquaculture to the Croatian part of the Adriatic Sea, in the 1970s, it was reported in the Lim Bay, in the North-eastern Adriatic. Until recently, there has been no research on the species in the Croatian part of the Adriatic. The aim of this research was to summarize existing and novel data on the distribution of M. gigas in coastal areas of the Eastern Adriatic and to provide a baseline for the future monitoring and assessment programmes of the species. Distribution of M. gigas was determined by three different methods: (i) a visual census of the presence of M. gigas specimens in the medio-littoral zone; (ii) DNA identification of M. gigas larvae in the water column; and (iii) the presence of M. gigas in the subtidal zone at depth between 25 and 40 m. Magallana gigas has a well-established population in the medio-littoral zone of natural and anthropogenic habitats along the coast of the North-eastern Adriatic Sea (west coast of Istria peninsula), but it is not present in the deeper layers . In the Central-eastern and South-eastern Adriatic Sea, the species was either absent or sporadically recorded with no evidence of fully established populations. Considering the great invasion success of M. gigas worldwide and effects that this species could have on the invaded ecosystem (e.g. competition for food and space with native species), detailed future monitoring is needed for the Eastern Adriatic Sea.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Wolfe, Marah L., Chelsea M. Bowers-Doerning, Anabell Espinosa, Ty Frantz, William J. Hoese, Joann G. Lam, Kailee R. Lamp et al. « Intra-decadal increase in globally-spread Magallana gigas in southern California estuaries ». PLOS ONE 19, n^o 5 (8 mai 2024) : e0302935. http://dx.doi.org/10.1371/journal.pone.0302935.

Texte intégral

Résumé :

Introduction and establishment of non-indigenous species (NIS) has been accelerated on a global scale by climate change. NIS Magallana gigas’ (formerly Crassostrea gigas’) global spread over the past several decades has been linked to warming waters, specifically during summer months, raising the specter of more spread due to predicted warming. We tracked changes in density and size distribution of M. gigas in two southern California, USA bays over the decade spanning 2010–2020 using randomly placed quadrats across multiple intertidal habitats (e.g., cobble, seawalls, riprap) and documented density increases by 2.2 to 32.8 times at 7 of the 8 sites surveyed across the two bays. These increases in density were coincident with 2–4° C increases in median monthly seawater temperature during summer months, consistent with global spread of M. gigas elsewhere. Size frequency distribution data, with all size classes represented across sites, suggest now-regular recruitment of M. gigas. Our data provide a baseline against which to compare future changes in density and abundance of a globally-spread NIS of significant concern.

Styles APA, Harvard, Vancouver, ISO, etc.

4

BATISTA, F. M., P. BOUDRY, A. DOS SANTOS, T. RENAULT et F. RUANO. « Infestation of the cupped oysters Crassostrea angulata, C. gigas and their first-generation hybrids by the copepod Myicola ostreae : differences in susceptibility and host response ». Parasitology 136, n^o 5 (5 mars 2009) : 537–43. http://dx.doi.org/10.1017/s0031182009005691.

Texte intégral

Résumé :

SUMMARYWe studied the prevalence and intensity of the parasitic copepod Myicola ostreae in 2 closely related oysters Crassostrea angulata and C. gigas and their F1 hybrids. The effects on host and host reaction were also analysed to better understand host-parasite relationships between copepods and bivalve molluscs. Full reciprocal crosses were carried out between C. angulata and C. gigas and the progenies were reared in the wild in Ria Formosa Lagoon (Portugal), allowing natural infestation by M. ostreae. Prevalence and intensity were significantly higher in C. angulata than in C. gigas. The parasite level of F1 hybrids was similar to C. angulata and significantly higher than in C. gigas. The results of our study support a hypothesis of dominantly inherited susceptibility to M. ostreae infestation. Moreover, copepods were observed on the gill surface of C. gigas engulfed by a capsule-like structure. Histological analyses revealed that the copepods were surrounded by a massive agglomerate of haemocyte-like cells encircled by a thin layer of fibroblast-like cells. This encapsulation response was not observed in C. angulata or in F1 hybrids. These results suggest that the differential susceptibility to M. ostreae between C. angulata and C. gigas may be ascribed to host defence factors.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Andrade, S. C., G. D. Rossi et N. M. Martinelli. « Dispersion Pattern of Giant Cicada (Hemiptera : Cicadidae) in a Brazilian Coffee Plantation ». Environmental Entomology 49, n^o 5 (1 septembre 2020) : 1019–25. http://dx.doi.org/10.1093/ee/nvaa096.

Texte intégral

Résumé :

Abstract The giant cicada Quesada gigas (Olivier, 1790) (Hemiptera: Cicadidae) is a major pest of coffee plants in Brazil. To ensure the rational management and ecological equilibrium, information about the behavior, dispersion, and reproduction of giant cicada is fundamental. The present work was conducted in an area of 97 ha planted with Coffea arabica L. to investigate adult dispersion as well as mating and oviposition behaviors of Q. gigas. A sound trap was placed at a ‘release point’ used for the attraction, marking, and release of adults in the area. The recapture of insects was performed with the same sound trap positioned at 20 points distributed at 100, 250, 400, and 1,000 m from the release point. The highest recapture rates of Q. gigas were observed at 100 m from the release point, and the lowest recapture rates were observed at 1,000 m. The presence of Eucalyptus plants in the area apparently influenced dispersion, as high recapture rates were observed at the sites close to Eucalyptus plants. One copulation of Q. gigas lasted 41.6 ± 0.43 min, and the period of a single oviposition bout was 30.0 ± 0.20 min. Quesada gigas adult longevity in the field was estimated to be 49 d. Both males and females were observed performing multiple matings.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Wilkie, Emma M., et Melanie J. Bishop. « Differences in shell strength of native and non-native oysters do not extend to size classes that are susceptible to a generalist predator ». Marine and Freshwater Research 63, n^o 12 (2012) : 1201. http://dx.doi.org/10.1071/mf12078.

Texte intégral

Résumé :

Whether non-native species proliferate to pest status can depend on top-down control from native predators. Among epifaunal molluscs, the shell serves as a main line of anti-predator defence and shell strength may determine the ease with which generalist predators can penetrate prey. We assessed whether, in eastern Australia, the faster growth of the non-native Pacific oyster, Crassostrea gigas, than that of the native Saccostrea glomerata comes at the cost of reduced investment in shell thickening, rendering the non-native oyster more susceptible to a generalist predator, the muricid gastropod Morula marginalba. Laboratory tests confirmed that among larger (>50-mm shell height) oysters, the shells of C. gigas were weaker than those of similar-sized S. glomerata. There were, however, no differences in shell strength or thickness between smaller S. glomerata and C. gigas of the size consumed by M. marginalba. In the absence of shell-strength differences among smaller oysters, M. marginalba preferentially consumed native over non-native oysters. When, however, M. marginalba had no choice of prey item, C. gigas was consumed at the same rate as the native oyster. Our results add to growing evidence that the invasion of C. gigas in eastern Australian estuaries is, at present, causing minimal disruption to trophic relationships.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Giarratana, F., D. Muscolino, Ch Beninati, G. Ziino, A. Giuffrida, M. Trapani et A. Panebianco. « Gymnorhynchus gigas in Lepidopus caudatus (Actinopterygii : Perciformes : Trichiuridae) : prevalence and related effects on fish quality ». Czech Journal of Food Sciences 32, No. 4 (29 juillet 2014) : 320–25. http://dx.doi.org/10.17221/330/2013-cjfs.

Texte intégral

Résumé :

We evaluated the effects of Gymnorhynchus gigas on the freshness and hygienic quality of Lepidopus caudatus. Total Volatile Basic Nitrogen (TVB-N), Trimethylamine Nitrogen (TMA-N), as well as Specific Spoilage Organisms (SSOs) are the most important freshness indicators in fish. Our study was carried-out on 65 specimens of L. caudatus kept in ice and stored at 2°C for different period of time. The microbiological charge of SSOs recovered on a portion of parasitised muscles (MP) was compared with those recovered on portions of parasite-free muscles (M). The contents of TVB-N and TMA-N on MP, M, and G. gigas larva/ae were measured using the Conway microdiffusion method. High prevalence (72.31%) of G. gigas in the specimens of L. caudatus from the Mediterranean sea was observed. No statistically significant differences (P < 0.05) between M and MP were found during storage. However, massive infestation of G. gigas on the muscle of the silver scabbardfish could negatively influence TVB-N values, without compromising the sensorial characteristic of fish.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Katrasov, S. V., A. N. Bugayets et V. V. Zharikov. « Evaluation of the Spatial Heterogeneity of the Pacific Oyster Magallana gigas ; (Thunberg, 1793) Cultivation Conditions Using the FARM Marifarm Management Model in Voevoda Bay ». Биология моря 49, n^o 1 (1 janvier 2023) : 37–44. http://dx.doi.org/10.31857/s0134347523010059.

Texte intégral

Résumé :

In the present study, using the Farm Aquaculture Resource Management (FARM), farm aquaculture resource management model, we calculated the potential productivity of plantations of the oyster Magallana gigas (Thunberg, 1793) (Bivalvia: Ostreidae) in Voevoda Bay (Sea of Japan, Peter the Great Bay, Russkiy Island). When calculating the productivity of cage and bottom plantations of M. gigas, we used the previously obtained results of numerical modeling of bay’s dynamics of hydrological parameters using the open software Delft3D-Flow, taking into account the inflow of fresh water into the bay in 1990–2019. To demonstrate the heterogeneity of growing conditions for M. gigas, three sites 100 × 100 m in size were selected, located in Kruglaya and Melkovodnaya Bays, as well as in the central part of Voevoda Bay. For each plot, modeling of 28 growing periods, lasting 22 months each was performed. The maximum values of oyster yield for the se-cond year of cultivation, expressed in tons of total wet weight, were selected, and distribution histograms for each area were presented. It was shown that, according to hydrological and biological indicators, the growing conditions even in small Voevoda bay are heterogeneous. It has been established that the variability in the productivity of M. gigas is associated mainly with the extreme uneven redistribution of primary production in Voevoda bay under the influence of hydrodynamic factors.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Jung, AS, HW van der Veer, CJM Philippart, AM Waser, BJ Ens, VN de Jonge et U. Schückel. « Impacts of macrozoobenthic invasions on a temperate coastal food web ». Marine Ecology Progress Series 653 (29 octobre 2020) : 19–39. http://dx.doi.org/10.3354/meps13499.

Texte intégral

Résumé :

Invasions of marine species are changing coastal food webs worldwide, impacting on trophic interactions between native species (e.g. predator-prey relationships). Here, the impact of 3 macrozoobenthic invasive species on food web structure and functioning at Balgzand (western Wadden Sea) is quantified by using ecological network analysis (ENA). The bivalves Ensis leei and Magallana gigas were observed for the first time in 1984 and 2001, respectively, and the polychaete Marenzelleria viridis appeared in 1989. Although E. leei and M. viridis reached similar peak biomasses in the 2000s (ca. 1700 and 2000 mg C m-2, respectively), the bivalve consumption was higher (>45% of total consumption) than that of the polychaete (<10%). Biomass and impact of M. gigas remained relatively low. E. leei occupied an ecological niche that was relatively unoccupied, which led to competitive advantage with respect to other suspension feeders. Increasing biomass of E. leei coincided with a 70% increase of trophic carbon transfer from primary to secondary producers and an 80% increase from secondary producers to detritus. Carbon flows from secondary producers to higher trophic levels were reduced by more than 60%. These shifts in trophic transfer were stronger than those observed during the invasion of M. gigas in the NE Wadden Sea. At Balgzand, biomass of M. gigas and M. viridis rapidly declined to low values in the 2010s, implying a temporally limited impact. In the 2010s, E. leei was still responsible for 30% of the total consumption in the 2010s, indicating a longer-term impact.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Слынько, Е. Е., et Ю. В. Слынько. « Genetic Diversity of Autochthonous and Introduced Mollusk Species Cultivated in the Black Sea ». Vestnik APK Verhnevolzh`ia, n^o 4(52) (25 décembre 2020) : 26–30. http://dx.doi.org/10.35694/yarcx.2020.52.4.005.

Texte intégral

Résumé :

В настоящее время в мирихозяйствах Чёрного моря интенсивно выращиваются три вида двустворчатых моллюсков: тихоокеанская, или гигантская, устрица (Crassostrea gigas, (Thunberg, 1793)), интродуцированная из Дальневосточных морей, и два вида аборигенов – мидия (Mytillus galloprovincialis Lamarck, 1819) и средиземноморский гребешок (Flexopecten glaber (Linnaeus, 1758)). В отношении всех трёх видов выявляются две основные проблемы – точное установление таксономического разнообразия и тенденции в изменениях генетического разнообразия. Все проанализированные устрицы из черноморского питомника могут быть отнесены к виду Crassostrea gigas. В исследованных гаплотипах C. gigas по генам COI и 16S mtDNA обнаруживаются особи, специфические как для Атлантики, так и для Тихого океана. Среди гаплотипов COI mtDNA из питомника Института биологии южных морей (ИнБЮМ) выявлен ранее не известный гаплотип (MF663324), который является специфическим для Крымской популяции культивируемых C. gigas. Нуклеотидные последовательности фрагмента гена COI у исследуемых особей мидий Чёрного моря при соотношении с последовательностями M. edulis и M. trossulus формировали общую филогенетическую группу, отличающуюся от M. californuanus. Это позволяет уверенно отнести исследованных нами особей к комплексу «голубой мидии». Все изученные экземпляры гребешка из заливов озера Донузлав были идентифицированы по гену 16S как вид Flexopecten glaber и одновременно как вид F. proteus. Если экземпляры из Донузлава имели р-расстояние от F. glaber 0.2%, то от F. proteus – 0.1%. Это свидетельствует о том, что виды F. glaber и F. proteus входят в один таксономический комплекс и являются таксономическими синонимами. Таким образом, в Чёрном море обитают следующие виды двустворчатых моллюсков: Crassostrea gigas, Mytillus galloprovincialis и Flexopecten glaber. Все они характеризуются существенным падением гаплотипического разнообразия, а чужеродный вид – тихоокеанская устрица – ещё и снижением нуклеотидного разнообразия. Currently, three species of bivalved mollusks are intensively grown in the Black Sea world farms: Pacific or giant, oyster (Crassostrea gigas, (Thunberg, 1793)) introduced from the Far Eastern Seas and two autochthonous species – mussel (Mytillus galloprovincialis Lamarck, 1819) and Mediterranean fan shell (Flexopecten glaber (Linnaeus, 1758)). In relation to all three species two main problems are identified – the exact establishment of taxonomic diversity and the trends in changes in genetic diversity. All analyzed oysters from the Black Sea fish hatchery can be assigned to the species Crassostrea gigas. In the studied C. gigas haplotypes individuals specific to both the Atlantic and the Pacific Ocean are found by COI and 16S mtDNA genes. Among the haplotypes of COI mtDNA from the fish hatchery of the Institute of Biology of the Southern Seas (IBSS) a previously unknown haplotype (MF663324) was identified which is specific to the Crimean population of cultured C. gigas. Nucleotide sequences of a fragment of the COI gene in the individuals of Black Sea mussels under investigation at a ratio with the sequences M. edulis and M. trossulus formed a common phylogenetic group different from M. californuanus. This allows us to confidently attribute the studied individuals to the blue mussel complex. All studied scallop specimens from Lake Donuzlav bays were identified by the gene 16S as a species of Flexopecten glaber and simultaneously as a species of F. proteus. If the Donuzlav specimens had a p-distance from F. glaber of 0.2%, then from F. proteus – 0.1%. This indicates that the species F. glaber and F. proteus are part of the same taxonomic complex and are taxonomic synonyms. Thus, the following species of bivalve mollusks live in the Black Sea: Crassostrea gigas, Mytillus galloprovincialis and Flexopecten glaber. All of them are characterized by a significant drop in haplotypic diversity and an alien species – the Pacific oyster – also a decrease in nucleotide diversity.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Fujibayashi, Megumu, Osamu Nishimura et Takashi Sakamaki. « The Negative Relationship between Fouling Organisms and the Content of Eicosapentaenoic Acid and Docosahexaenoic Acid in Cultivated Pacific Oysters, Crassostrea gigas ». Marine Drugs 19, n^o 7 (25 juin 2021) : 369. http://dx.doi.org/10.3390/md19070369.

Texte intégral

Résumé :

Bivalves serve as an important aquaculture product, as they are the source of essential fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in our diet. However, their cultivation in the wild can be affected by fouling organisms that, in turn, affect their EPA and DHA content. The effects of fouling organisms on the EPA and DHA contents of cultivated bivalves have not been well documented. We examined the effects of fouling organisms on the EPA and DHA contents and condition index of cultured oysters, Crassostrea gigas, in an aquaculture system. We sampled two-year-old oysters from five sites in Shizugawa Bay, Japan, in August 2014. Most of the fouling organisms were sponges, macroalgae, and Mytilus galloprovincialis. A significant negative relationship existed between the DHA content in C. gigas and the presence of sponges and macroalgae. A lower C. gigas EPA content corresponded to a higher M. galloprovincialis fouling mass and a lower C. gigas condition index. This can be explained by dietary competition between C. gigas and M. galloprovincialis for diatoms, which were the main producer of EPA in our study sites. Our findings indicate that fouling organisms likely reduce the EPA and DHA content in cultivated oysters. Therefore, our results suggest that the current efforts to remove fouling organisms from oyster clusters is an effective strategy to enhance the content of EPA and DHA in oysters.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Wood, Louisa E., Tiago A. M. Silva, Richard Heal, Adam Kennerley, Paul Stebbing, Liam Fernand et Hannah J. Tidbury. « Unaided dispersal risk of Magallana gigas into and around the UK : combining particle tracking modelling and environmental suitability scoring ». Biological Invasions 23, n^o 6 (3 février 2021) : 1719–38. http://dx.doi.org/10.1007/s10530-021-02467-x.

Texte intégral

Résumé :

AbstractMarine non-indigenous species are a significant threat to marine ecosystems with prevention of introduction and early detection considered to be the only effective management strategy. Knowledge of the unaided pathway has received relatively little attention, despite being integral to the implementation of robust monitoring and surveillance. Here, particle tracking modelling is combined with spatial analysis of environmental suitability, to highlight UK coastal areas at risk of introduction and spread of Magallana gigas by the unaided pathway. ‘Introduction into UK’ scenarios were based on spawning from the continental coast, Republic of Ireland, Channel Islands and Isle of Man and ‘spread within UK’ scenarios were based on spawning from known UK wild populations and aquaculture sites. Artificial structures were included as spawning sites in an introduction scenario. The UK coast was scored, based on parameters influencing larval settlement, to reflect environmental suitability. Risk maps were produced to highlight areas of the UK coast at elevated risk of introduction and spread of M. gigas by the unaided pathway. This study highlights that introduction of M. gigas into UK waters via the unaided pathway is possible, with offshore structures increasing the potential geographical extent of introduction. Further, there is potential for substantial secondary spread from aquaculture sites and wild populations in the UK. The results of the study are considered in the context of national M. gigas management, whilst the approach is contextualised more broadly as a tool to further understanding of a little-known, yet significant pathway.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Armstrong, KN, et SD Anstee. « The ghost bat in the Pilbara : 100 years on. » Australian Mammalogy 22, n^o 2 (2000) : 93. http://dx.doi.org/10.1071/am00093.

Texte intégral

Résumé :

This paper summarises the roost habitat and distribution of the ghost bat, Macroderma gigas (Dobson, 1880), in the Pilbara region of Western Australia, with particular emphasis on natural habitats. The preferred habitat of M. gigas in the Hamersley Ranges appears to be caves beneath bluffs of low rounded hills composed of Marra Mamba geology. Habitats were also found in the larger hills of Brockman Iron Formation in the Hamersley Range, and other formations beneath bluffs composed of Gorge Creek Group geology to the north east. Granite rockpiles are also used in the eastern Pilbara. A summary of Pilbara records from numerous sources is presented, including anecdotal accounts and other new records. This includes a newly discovered maternity site from the Hamersley Ranges, only the third reported from natural cave formations in the region. Threats to M. gigas in the region are highlighted and include disturbances associated with mining and entanglement in barbed wire fences.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Wu, Xiaoci, Pengchao Jin, Yang Zhang et Wei Yu. « Spatial Distribution and Abundance of a Pelagic Squid during the Evolution of Eddies in the Southeast Pacific Ocean ». Journal of Marine Science and Engineering 12, n^o 6 (18 juin 2024) : 1015. http://dx.doi.org/10.3390/jmse12061015.

Texte intégral

Résumé :

The Humboldt squid (Dosidicus gigas), is a significant economic species off Peru. The abundance and distribution of the species are highly susceptible to fluctuations in marine environmental conditions. The evolution of mesoscale eddies represents one of the dynamic processes in the ocean, exerting varying degrees of influence on regional biogeochemical processes from generation to dissipation. However, the mechanisms governing the regulation of abundance and spatial distribution of D. gigas off Peru during this evolution remain unclear. Therefore, this study employed normalization techniques and the habitat suitability index (HSI) model, utilizing data from the D. gigas fishery, mesoscale eddies, and marine environmental factors (including sea surface temperature, temperature at 50 m depth, and chlorophyll-a concentration) to analyze the changes in environmental conditions, abundance, spatial distribution, and habitat of D. gigas off Peru during the evolution of mesoscale eddies. The results indicate that eddies undergo four stages: formation, intensification, maturity, and decay. During eddy evolution, the abundance of D. gigas exhibited an initial increase and a subsequent decrease within cyclonic eddies (CEs), whereas, within anticyclonic eddies (AEs), abundance showed a gradual decline. The outcome of the HSI model revealed that, the habitat suitability and the proportion of suitable habitat areas within eddies were highly consistent with the abundance of D. gigas during all stages of the eddies other than the intensification stage of AEs. The study speculated that both CEs and AEs can create favorable environmental conditions during the maturity stage, thereby leading to an increase in suitable habitat and abundance of D. gigas. These findings emphasize the significant impact of mesoscale eddy evolution on the abundance and habitat distribution of D. gigas.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Lunz, Alexandre Mehl, Roni de Azevedo, Moisés Mourão Júnior, Odineila Martins Monteiro, Alessandro Lechinoski et Luciano Zumerle Zaneti. « Método para monitoramento de ninfas de cigarras e controle com inseticidas em reflorestamentos com paricá ». Pesquisa Agropecuária Brasileira 45, n^o 7 (juillet 2010) : 631–37. http://dx.doi.org/10.1590/s0100-204x2010000700001.

Texte intégral

Résumé :

O objetivo deste trabalho foi estabelecer um método para o monitoramento da população de cigarras (Quesada gigas) e para a avaliação da eficácia de doses de thiamethoxam, carbofuran e imidaclopride no controle de ninfas, em reflorestamento com paricá (Schizolobium parahyba var. amazonicum). Foram utilizadas as seguintes dosagens de inseticidas: 2,0, 4,0 e 6,0 kg ha-1 do produto comercial Actara (250 WG), para o princípio ativo thiamethoxan; 7,15, 14,30, 21,45 L ha-1 de Furadan (350 FS), para o carbofuran; e 4,5, 9,0, 13,5 L ha-1 de Provado (200 SC), para o imidaclopride. As três dosagens de cada produto foram aplicadas em área total. Foram realizadas três avaliações quinzenais, posteriores à aplicação, em que foram contabilizados os números de buracos e de ninfas vivas, por meio da abertura, com implemento tratorizado, de trincheiras com 7 m de comprimento, 0,8 m de largura e 0,07 m de profundidade. Todos os princípios ativos testados foram eficientes na redução da população de ninfas de Q. gigas, mas não houve efeito significativo das doses avaliadas. Os princípios ativos carbofuran e thiamethoxan são os mais promissores, com controle de 75-80% da infestação de ninfas. A abertura de trincheiras com o implemento tratorizado é eficaz no monitoramento da população de ninfas de Q. gigas, em reflorestamentos com paricá.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Paredes-López, Daniel, Rizal Robles-Huaynate, Carmela Rebaza-Alfaro, José Delgado-Ramírez et U. Aldava-Pardave. « Effect of stocking density of juvenile Arapaima gigas on rearing water quality hematological and biochemical profile, and productive performance ». Latin American Journal of Aquatic Research 49, n^o 2 (3 mai 2021) : 193–201. http://dx.doi.org/10.3856/vol49-issue2-fulltext-2588.

Texte intégral

Résumé :

At inadequate stocking density, fish generally show different physiological responses. The effects of stocking density on Arapaima gigas larvae productive parameters have been determined in a previous study. This study aimed to evaluate the effect of the stocking density on the water quality, hematological and biochemical profile, and productive performance of juvenile A. gigas. One hundred and eighty twelve months old, A. gigas were distributed into tanks using initial densities of 103.90, 157.95 and 220.11 kg m-3 with three replicates. Ammoniacal nitrogen, carbon dioxide, dissolved oxygen pH, alkalinity, and hardness were determined using a LaMotte Fish Farm 9, AQ-2 model, Maryland, USA, freshwater test kit. Blood samples were taken at 13, 14, and 15 months old by pricking the caudal vein and profiles of glucose (Glu), total protein (TP), albumin, aspartate transaminase (AST), alanine transaminase (ALT), and urea, were determined in blood serum. Rearing water was saturated in ammoniac nitrogen, carbon dioxide, and dissolved oxygen but have not changed with the increase of stocking density (P < 0.05), Erythrocyte's count (EC) diminished (P < 0.05), nonetheless, hemoglobin, mean concentration hemoglobin (MCH) and mean cell volume (MCV) increased (P < 0.05). Albumin, AST, ALT and urea diminished at 220.11 kg m-3 stocking density (P < 0.05). The feed intake increased, final biomass gain was 100.26 ± 19.00, 119.10 ± 13.95, and 130.24 ± 08.07 kg m-3, but did not change as density increased (P < 0.05). Juveniles of A. gigas showed no variation in productive performance with an increase in the stocking density. Furthermore, hematological and biochemical adapting profile to high stocking densities characterized this species.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Val, Adalberto Luís, Elizabeth Gusmão Affonso, Roberto Huet de Salvo Souza, Vera Maria Fonseca de Almeida-Val et Marcia Alves Ferreira de Moura. « Inositol pentaphosphate in the erythrocytes of an Amazonian fish, the pirarucu (Arapaima gigas) ». Canadian Journal of Zoology 70, n^o 5 (1 mai 1992) : 852–55. http://dx.doi.org/10.1139/z92-121.

Texte intégral

Résumé :

During the Alpha Helix expeditions to the rivers of the Amazon basin, inositol pentaphosphate (IPP) was detected in the erythrocytes of Arapaima gigas. We analyzed the intraerythrocytic phosphate levels of A. gigas specimens during the first year of life in captivity. IPP increased slowly during the first year, stabilizing at around 7 mM when the animals reached 1–1.5 m in length. ATP and GTP concentrations decreased in parallel. Wild animals within the same size range showed similar intraerythrocytic IPP levels. These changes represent qualitative and quantitative adjustments of the principal modulators of haemoglobin–oxygen affinity in the erythrocytes of A. gigas. These temporal changes seem to play an important physiological role, since this species changes its respiratory habit from aquatic respiration to obligatory air breathing, when it uses a modified swim bladder.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Nelson, J. E., K. A. Christian et R. V. Baudinette. « Anatomy of the nasal passages of three species of Australian bats in relation to water loss ». Australian Journal of Zoology 55, n^o 1 (2007) : 57. http://dx.doi.org/10.1071/zo06101.

Texte intégral

Résumé :

A previous study found substantial variation in rates of water loss in three species of Australian bats, with the orange leafnosed bat (Rhinonycteris aurantius) having a rate more than twice that of the large bentwing bat (Miniopterus schreibersii) and the ghost bat (Macroderma gigas). Using histological sections, we examined the nasal passages of these species to determine whether any of the species have complex turbinals that may function to reduce respiratory water loss. M. schreibersii has the most complex nasal passages, and R. aurantius has the simplest. Calculations indicate that the respiratory water loss of R. aurantius and M. schreibersii are similar, but this indicates that the nasal turbinals of M. schreibersii function to conserve pulmonary water given that the metabolic rate, and therefore respiratory frequency, is higher in M. schreibersii. R. aurantius and M. gigas echolocate by emitting pulses from the nostrils whereas M. schreibersii emits pulses from the mouth. The structure of the nasal passages of nasal emitters is constrained by the demands of echolocation, and this may preclude the development of complex turbinal arrangements required for the conservation of respiratory water.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Mikac, Barbara, Alessandro Tarullo, Marina Antonia Colangelo, Marco Abbiati et Federica Costantini. « Shell Infestation of the Farmed Pacific Oyster Magallana gigas by the Endolith Bivalve Rocellaria dubia ». Diversity 13, n^o 11 (23 octobre 2021) : 526. http://dx.doi.org/10.3390/d13110526.

Texte intégral

Résumé :

Oyster shells are substratum for different epibiontic and endobiontic organisms, including pests and parasites. Rocellaria dubia is endolithic and facultative tube-dwelling bivalve, boring in different calcareous substrates, including the shells of bivalves. In 2020, R. dubia was found as endolithic in the shells of the Pacific oyster Magalana gigas, from an oyster farm off the Sacca di Goro lagoon (Emilia-Romagna region, Northern Adriatic Sea, Italy). The purpose of this study was to describe this newly recorded association. Altogether, 136 specimens of R. dubia were found in 15 oysters, photographed under a stereoscope, and their length was measured. Heavily infested oysters hosted tens of R. dubia borers, which were perforating the whole thickness of the oyster valves. The flesh of these oysters was heavily damaged, suggesting parasitic association. R. dubia specimens were categorized into three age classes (0–1, 1–2, and 2–3 years old). M. gigas/R. dubia might be a widespread association, overlooked due to the very scarce research on macrofauna associated with M. gigas. Considering the negative effects of R. dubia endobiosis on oyster fitness, and possible impacts on oyster aquaculture, further research should be conducted in order to elucidate the distribution and ecological characteristics of this parasitic association.

Styles APA, Harvard, Vancouver, ISO, etc.

20

O’ Reilly, A. J., C. Laide, A. Maloy, S. Hutton, B. Bookelaar, K. O’ Sullivan, S. A. Lynch et S. C. Culloty. « The role of the mussel Mytilus spp. in the transmission of ostreid herpesvirus-1 microVar ». Parasitology 145, n^o 8 (21 décembre 2017) : 1095–104. http://dx.doi.org/10.1017/s0031182017002244.

Texte intégral

Résumé :

AbstractThe Pacific oyster Crassostrea gigas contributes significantly to global aquaculture; however, C. gigas culture has been affected by ostreid herpesvirus-1 (OsHV-1) and variants. The dynamics of how the virus maintains itself at culture sites is unclear and the role of carriers, reservoirs or hosts is unknown. Both wild and cultured mussels Mytilus spp. (Mytilus edulis, Mytilus galloprovincialis and hybrids) are commonly found at C. gigas culture sites. The objective of this study was to investigate if Mytilus spp. can harbour the virus and if viral transmission can occur between mussels and oysters. Mytilus spp. living at oyster trestles, 400–500 m higher up the shore from the trestles and up to 26 km at non-culture sites were screened for OsHV-1 and variants by all the World Organization for Animal Health (OIE) recommended diagnostic methods including polymerase chain reaction (PCR), quantitative PCR (qPCR), histology, in situ hybridization and confirmation using direct sequencing. The particular primers that target OsHV-1 and variants, including OsHV-1 microVar (μVar), were used in the PCR and qPCR. OsHV-1 μVar was detected in wild Mytilus spp. at C. gigas culture sites and more significantly the virus was detected in mussels at non-culture sites. Cohabitation of exposed wild mussels and naïve C. gigas resulted in viral transmission after 14 days, under an elevated temperature regime. These results indicate that mussels can harbour OsHV-1 μVar; however, the impact of OsHV-1 μVar on Mytilus spp. requires further investigation.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Sun, Youmei, Jingjing Fu, Enshuo Zhang, Luyao Dong, Xuebo Cui, Yanan Sun, Zhizhong Wang et al. « Fingerprint Analysis of Volatile Flavor Compounds in Crassostrea gigas of Different Ploidy and Gender under High-Temperature Incubation ». Molecules 28, n^o 19 (28 septembre 2023) : 6857. http://dx.doi.org/10.3390/molecules28196857.

Texte intégral

Résumé :

In this study, diploid, triploid, and tetraploid Crassostrea gigas samples were subjected to gas chromatography and ion mobility (GC-IMS) to identify and analyze volatile compounds and flavor fingerprints under conditions of high-temperature incubation. The GC-IMS technology identified a total of 54 volatile components in C. gigas. The contents of 1-octen-3-ol, butyl pentanoate, p-methyl anisole, and 2-methyl-2-hepten-6-one in male oysters were significantly higher than in females, while the contents of phenylacetaldehyde, benzaldehyde, 2-ethyl-3-methylpyrazine, 2-ethylfuran, and 2,4-hexadienal in female oysters were significantly higher than in males. The contents of non-3-en-2-one-M and 1-pentanol in diploids were significantly higher than in triploids and tetraploids, while the content of 2,4-hexadienal in tetraploids was significantly higher than in diploids and tetraploids. The contents of ethyl acetate, ethyl-2-butenoate, and butanal in tetraploids were significantly higher than those in diploids and triploids. The results of a principal components analysis showed that different samples were relatively independently clustered, allowing the ability to distinguish different oyster samples. The chemical fingerprints of volatile compounds of C. gigas with different ploidy and gender under high-temperature incubation were established, and the volatile substance contours of C. gigas were visualized. The results provide a reference for distinguishing the ploidy and gender of C. gigas under conditions of high-temperature incubation.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Fang, Xingnan, Xin Zhang, Xinjun Chen et Wei Yu. « The Impact of Ekman Pumping and Transport on Dosidicus gigas (Jumbo Flying Squid) Fishing Ground by Chinese Jiggers off the Coast of Peru ». Journal of Marine Science and Engineering 13, n^o 2 (31 janvier 2025) : 280. https://doi.org/10.3390/jmse13020280.

Texte intégral

Résumé :

Upwelling is often associated with high productivity, biodiversity, and fishery resource abundance. This study employed a generalized additive model (GAM) to analyze the effects of Ekman pumping and transport on the abundance and distribution of jumbo flying squid (Dosidicus gigas) using wind field data and Chinese commercial fishing catch data off Peru from 2012 to 2020. The results indicate that the spatial distribution of Ekman pumping and transport exhibited significant monthly variation and exerted a considerable impact on the abundance and distribution of D. gigas. Ekman pumping fluctuated between 4.98 × 10−9 to 6.84 × 10−7 m/s, with the strongest upwelling effects observed from February to March and October to December. Ekman transport varied from 0.89 to 2.56 m3/s and peaked in August. The GAM results indicate that the catch per unit effort (CPUE) of D. gigas was significantly affected by Ekman pumping, while the latitudinal gravity centers (LATG) of D. gigas were significantly influenced by Ekman transport and chlorophyll-a concentration (Chl-a). Both hydrodynamic processes had a significant influence on Chl-a. Ekman pumping contributed greatly to upwelling formation, significantly increasing Chl-a concentration in the northern region, while strong Ekman transport pushed high-Chl-a coastal waters offshore in the central and southern regions when Ekman pumping was weaker, resulting in increasing offshore Chl-a concentrations. Furthermore, Chl-a concentration was significantly positively correlated with Ekman pumping after a two-month lag. An El Niño weakened the intensity of Ekman pumping, leading to notable declines in Chl-a concentration and D. gigas CPUE. These findings demonstrate that Ekman pumping and transport significantly influence the distribution of Chl-a, to which D. gigas is sensitive, influencing the abundance and distribution of this species off the coast of Peru.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Selfiannisa, Fania, Suherni Susilowati, Poedji Hastutiek, Lucia Tri Suwanti, Kusnoto Kusnoto et Agus Sunarso. « Investation of Ectoparasites In Chickens In Village of Kramat District of Bangkalan Regency of Bangkalan ». Journal of Parasite Science 2, n^o 2 (3 décembre 2019) : 57. http://dx.doi.org/10.20473/jops.v2i2.16400.

Texte intégral

Résumé :

A study on the infestation of ectoparasites in chicken’s raised in Village of Kramat, District of Bangkalan, Regency of Bangkalan was conducted between July to October 2017. A total of 60 chickens were examined based on their sex and region of the chicken’s body. Identification was carried out on ectoparasites found identified using permanent mounting methods and scraping. The types of ectoparasites were M. gallinae 77%, L. caponis 52%, M. stramineus 15%, R. sanguineus 3%, G. gallinae 2%, G. gigas 2%, and D. gallinae 2%. Data were analyzed using Chi Square and Correspondence. The results of infestation was higher in males than females, although the difference was not statistically significant (P>0.05). Results of analysis of the pattern of investation of ectoparasites in the region that includes in males and females body are M. gallinae in the region of the back. L. caponis in the region of the wings. M. stramineus. R. sanguineus in the region of the head-neck, G. gigas in the region of belly, G. gallinae in the region of the leg just found in the males body. D. gallinae in the region of the leg just found in the females body.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Rzedowski, J. « Tres dicotiledóneas mexicanas nuevas de posible interés ornamental ». Botanical Sciences, n^o 35 (8 décembre 2016) : 37. http://dx.doi.org/10.17129/botsci.1151.

Texte intégral

Résumé :

Populus simaroa, Castilleja venusta y Montarnoa gigas se describen como nuevas a base de material colectado en los estados de Guerrero y México. Populus simaroa sp.n. pertenece a la sección Populus y posiblemente está relacionada con P. grandidentata Michx. Es particularmente notable en su comportamiento fenológico, pues el árbol pierde las hojas al iniciarse la época lluviosa y se cubre de follaje al principio del período de sequía. Se conoce de un área relativamente amplia, pero en general parece ser planta escasa. Castilleja venusta sp.n. es una planta anual, que se diferencia de los demás miembros ele la sección Epichroma por el conspicuo labio inferior de la corola. Sólo se ha colectado en el Cerro Teotepec, Guerrero. Montanoa gigas sp.n., árbol hasta de 20 m de alto, pertenece al grupo de M. quadrangularis Sch. Bip. y se distingue de M. hexagona Rob. & Greenrn. principalmente en la morfología de sus páleas. Se conoce de varias localidades de la Sierra Madre del Sur de Guerrero.

Styles APA, Harvard, Vancouver, ISO, etc.

25

ACARLI, Sefa, Harun YILDIZ et Pervin VURAL. « Morphometric Characteristics of Invasive Species Magallana gigas (Thunberg, 1793) in Bandırma Bay, Marmara Sea ». Marine Science and Technology Bulletin 12, n^o 3 (28 septembre 2023) : 322–31. http://dx.doi.org/10.33714/masteb.1337592.

Texte intégral

Résumé :

Türkiye’s seas are the scene of the spread of invasive species in the entire Mediterranean basin due to the marine transportation of alien species and intensive aquaculture activities. In order to protect the natural ecosystem and track invasive species’ effects, these species must first be accurately identified and their distribution areas specified. The alien species, Magallana gigas (Pacific oyster), has introduced along the Turkish coasts. This study was carried out to determine the morphometric characteristics of Magallana gigas in the Bandırma Bay-Balıkesir between November 2013 and October 2014. Shell length varied between 68.08 mm (February) and 93.14 mm (April) during the year. Shell height was measured at the lowest 41.90 mm in February, and the highest 59.46 mm in June. Shell width was 35.80 mm in November when the study started, and it decreased gradually and reached its lowest value in February. W/L relationship of M. gigas was calculated as W=0.411×L2.653(R2=0.064) This study includes knowledges on morphometric relationships for the Pacific oyster which is crucial for the management of fisheries, aquaculture activities and native species (Ostrea edulis).

Styles APA, Harvard, Vancouver, ISO, etc.

26

Lima, Luciana Sampaio, Aldo Aparecido Proietti-Junior, Yan Corrêa Rodrigues, Marcelo Cleyton da Silva Vieira, Luana Nepomuceno Gondim Costa Lima, Cintya de Oliveira Souza, Verônica Dias Gonçalves, Marcelo de Oliveira Lima, Dália dos Prazeres Rodrigues et Karla Valéria Batista Lima. « High Genetic Diversity and Antimicrobial Resistance in Escherichia coli Highlight Arapaima gigas (Pisces : Arapaimidae) as a Reservoir of Quinolone-Resistant Strains in Brazilian Amazon Rivers ». Microorganisms 10, n^o 4 (13 avril 2022) : 808. http://dx.doi.org/10.3390/microorganisms10040808.

Texte intégral

Résumé :

The increasing prevalence of multi-drug resistant (MDR) Escherichia coli in distinct ecological niches, comprising water sources and food-producing animals, such as fish species, has been widely reported. In the present study, quinolone-resistant E. coli isolates from Arapirama gigas, a major fish species in the Brazilian Amazon rivers and fish farms, were characterized regarding their antimicrobial susceptibility, virulence, and genetic diversity. A total of forty (40) specimens of A. gigas, including 20 farmed and 20 wild fish, were included. Thirty-four quinolone-resistant E. coli isolates were phenotypically tested by broth microdilution, while resistance and virulence genes were detected by PCR. Molecular epidemiology and genetic relatedness were analyzed by MLST and PFGE typing. The majority of isolates were classified as MDR and detected harboring blaCTX-M, qnrA and qnrB genes. Enterotoxigenic E. coli pathotype (ETEC) isolates were presented in low prevalence among farmed animals. MLST and PFGE genotyping revealed a wide genetic background, including the detection of internationally spread clones. The obtained data point out A. gigas as a reservoir in Brazilian Amazon aquatic ecosystems and warns of the interference of AMR strains in wildlife and environmental matrices.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Matrai, Eszter, Hau Yin Alfred Chan, Fung Ming Leung, Shaw Ting Kwok, Xiao Lin et Paolo Martelli. « Point for Enrichment, Point for Welfare—Testing Use of a Laser Pointer with Arapaima gigas ». Animals 13, n^o 8 (17 avril 2023) : 1370. http://dx.doi.org/10.3390/ani13081370.

Texte intégral

Résumé :

The arapaima (Arapaima gigas) is one of the largest freshwater fish species, known to exceed 3 m in total length. It is listed as Data Deficient by the IUCN. A. gigas is native to the Amazon River basin where they are an important food source. Arapaimas are also farmed for meat and for live specimens in various South American and Asian countries. Despite decades of keeping the species in public aquariums, little is known of its behaviour and cognitive abilities. This pilot study provides baseline data on using a green laser pointer as environmental enrichment for this species under human care. The data collection included 18 observations before the use of the laser pointer (baseline) and 18 observations during the use of the laser pointer (test). Ten behaviours were monitored, investigating physical contact, activity pattern and habitat use by the fish. During the test, the fish significantly increased their presence in the tank, their level of activity and their use of the habitat. This pilot study provides valuable baseline data for further investigations demonstrating the value of a laser pointer as environmental enrichment for A. gigas under human care.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Vereecken, Nicolas J., Pietro Niolu, Éric Dufrêne et Gérard Le Goff. « Observations sur les nids de deux chalicodomes et leurs occupants en Sardaigne (Italie) ». Osmia 4 (2010) : 15–19. http://dx.doi.org/10.47446/osmia4.4.

Texte intégral

Résumé :

Observations on the nests of two chalicodomes and their occupants in Sardinia (Italy). - We here provide field observations made in spring 2008 in Sardinia on the nesting biology of two mason bees, Megachile (Chalicodoma) parietina (Geoffroy in Fourcroy 1785) and M. (C.) sicula (Rossi 1792) whose females occasionally construct egg-shaped nests perched on tree twigs. Active nests of M. (C.) parietina were also exploited by females of Osmia signata Erichson 1835 and those of M. (C.) sicula were found to be parasitised by Leucospis gigas Fabricius 1793.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Kopytina, N. I., et E. A. Bocharova. « Fouling communities of microscopic fungi on various substrates of the Black Sea ». Biosystems Diversity 29, n^o 4 (27 octobre 2021) : 345–53. http://dx.doi.org/10.15421/012144.

Texte intégral

Résumé :

Fungi are the most active biodeteriorators of natural and man-made materials. The article presents generalizations of the studies (2001–2019) of communities of microscopic fungi within biofilms on various substrates: shells of live Mytilus (Mytilus galloprovincialis, 670 specimens) and Ostreidae (Crassostrea gigas, 90 specimens), fragments of driftwood (over 7,000), stones (40), concrete of hydrotechnical constructions along the shoreline (80) and wood between concrete blocks in constructions on the shores (80). The studies were carried out in Odessa Oblast, the coastal zone of Sevastopol and open area of the Black Sea. There were identified 123 species of micromycetes, belonging to 65 genera, 33 families, 21 orders, 10 classes, 4 divisions, 2 kingdoms: Fungi and Chromista (fungi-like organisms). The Chromista kingdom was represented by 1 species – Ostracoblabe implexa, on shells of C. gigas. The number of species of micromycetes on various substrates varied 23 (wood between concrete blocks of hydrotechnical constructions) to 74 (shells of M. galloprovincialis at the depths of 3 and 6 m). On all the substrates, the following species were found; Alternaria alternata, Botryotrichum murorum. The communities were found to contain pathogenic fungi Aspergillus fumigatus (shells of mollusks, stones, concrete), A. terreus (concrete), Fusarium oxysporum, Pseudallescheria boydii (shells of mollusks). The best representation was seen for the Pleosporales order – from 12.9% (shells of M. galloprovincialis, 0.3 m depth) to 33.3% (shells of C. gigas) of the species composition. Toxin-producing species of Microascales in mycological communities accounted for 1.6% (driftwood) to 40.0% (concrete), and were also observed on shells of Bivalvia – 11.1–32.3%. Similarity of species composition of mycological communities according to Bray-Curtis coefficient varied 21.1% (driftwood and concrete, 10 shared species) to 72.7% (shells of M. galloprovincialis, the depths of 3 and 7 m and shells of C. gigas, 45 shared species). Using graphs of indices of mean taxonomic distinctness (AvTD, Δ+) and variation (Variation in Taxonomic Distinctness index, VarTD, Λ+), we determined deviations of taxonomic structure of the studied mycological communities from the level of mean expected values, calculated based on the list of species, taking into account their systematic positions. The lowest values of index Δ+ were determined for communities on shells of M. galloprovincialis, 0.3 m depth, driftwood, stones and concrete. These communities had uneven distribution of species according to higher taxonomic ranks and minimum number of the highest taxa: 4–6 classes, 1–2 divisions, Fungi kingdom. Disproportion in species composition with decrease in the number of the highest taxa occurred in extreme environmental conditions. Using index Λ+, we found that the most complex taxonomic structure of fungi communities has developed on concrete and shells of C. gigas. In mycological communities on those substrates, the number of species was low (25 and 46), but they belonged to 4–7 classes, 2–3 divisions, 1–2 kingdoms. To compare the structures of mycological communities that have developed in such substrates in biotopes sea, sea-land-air, land-air, we compiled a list of fungi based on the literature data, which, taking into account our data, comprised 445 species of 240 genera, 103 families, 51 orders, 15 classes, 5 divisions, 2 kingdoms. The analysis revealed that on substrates with similar chemical composition, in all the biotopes, the species of the same divisions dominated (genus and family may vary). Therefore, in the biotope land-air – Hypocreales, Pleosporales, Eurotiales (genera Acremonium, Fusarium, Alternaria, Aspergillus, Penicillium); sea – Pleosporales, Eurotiales, Microascales (Alternaria, Aspergillus, Penicillium, Corollospora); sea-land-air – Pleosporales, Microascales (Alternaria, Leptosphaeria, Aspergillus, Penicillium, Corollospora, Halosarpheia). Monitoring of species composition of myxomycetes is needed in farms that cultivate industrial objects, recreation sites, various buildings for prevention of mycotoxin intoxication and infestation by mycodermatoses and other diseases caused by opportunistic and pathogenic fungi.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Kopytina, N. I., et E. A. Bocharova. « Fouling communities of microscopic fungi on various substrates of the Black Sea ». Biosystems Diversity 29, n^o 4 (27 octobre 2021) : 345–53. http://dx.doi.org/10.15421/10.15421/012144.

Texte intégral

Résumé :

Fungi are the most active biodeteriorators of natural and man-made materials. The article presents generalizations of the studies (2001–2019) of communities of microscopic fungi within biofilms on various substrates: shells of live Mytilus (Mytilus galloprovincialis, 670 specimens) and Ostreidae (Crassostrea gigas, 90 specimens), fragments of driftwood (over 7,000), stones (40), concrete of hydrotechnical constructions along the shoreline (80) and wood between concrete blocks in constructions on the shores (80). The studies were carried out in Odessa Oblast, the coastal zone of Sevastopol and open area of the Black Sea. There were identified 123 species of micromycetes, belonging to 65 genera, 33 families, 21 orders, 10 classes, 4 divisions, 2 kingdoms: Fungi and Chromista (fungi-like organisms). The Chromista kingdom was represented by 1 species – Ostracoblabe implexa, on shells of C. gigas. The number of species of micromycetes on various substrates varied 23 (wood between concrete blocks of hydrotechnical constructions) to 74 (shells of M. galloprovincialis at the depths of 3 and 6 m). On all the substrates, the following species were found; Alternaria alternata, Botryotrichum murorum. The communities were found to contain pathogenic fungi Aspergillus fumigatus (shells of mollusks, stones, concrete), A. terreus (concrete), Fusarium oxysporum, Pseudallescheria boydii (shells of mollusks). The best representation was seen for the Pleosporales order – from 12.9% (shells of M. galloprovincialis, 0.3 m depth) to 33.3% (shells of C. gigas) of the species composition. Toxin-producing species of Microascales in mycological communities accounted for 1.6% (driftwood) to 40.0% (concrete), and were also observed on shells of Bivalvia – 11.1–32.3%. Similarity of species composition of mycological communities according to Bray-Curtis coefficient varied 21.1% (driftwood and concrete, 10 shared species) to 72.7% (shells of M. galloprovincialis, the depths of 3 and 7 m and shells of C. gigas, 45 shared species). Using graphs of indices of mean taxonomic distinctness (AvTD, Δ+) and variation (Variation in Taxonomic Distinctness index, VarTD, Λ+), we determined deviations of taxonomic structure of the studied mycological communities from the level of mean expected values, calculated based on the list of species, taking into account their systematic positions. The lowest values of index Δ+ were determined for communities on shells of M. galloprovincialis, 0.3 m depth, driftwood, stones and concrete. These communities had uneven distribution of species according to higher taxonomic ranks and minimum number of the highest taxa: 4–6 classes, 1–2 divisions, Fungi kingdom. Disproportion in species composition with decrease in the number of the highest taxa occurred in extreme environmental conditions. Using index Λ+, we found that the most complex taxonomic structure of fungi communities has developed on concrete and shells of C. gigas. In mycological communities on those substrates, the number of species was low (25 and 46), but they belonged to 4–7 classes, 2–3 divisions, 1–2 kingdoms. To compare the structures of mycological communities that have developed in such substrates in biotopes sea, sea-land-air, land-air, we compiled a list of fungi based on the literature data, which, taking into account our data, comprised 445 species of 240 genera, 103 families, 51 orders, 15 classes, 5 divisions, 2 kingdoms. The analysis revealed that on substrates with similar chemical composition, in all the biotopes, the species of the same divisions dominated (genus and family may vary). Therefore, in the biotope land-air – Hypocreales, Pleosporales, Eurotiales (genera Acremonium, Fusarium, Alternaria, Aspergillus, Penicillium); sea – Pleosporales, Eurotiales, Microascales (Alternaria, Aspergillus, Penicillium, Corollospora); sea-land-air – Pleosporales, Microascales (Alternaria, Leptosphaeria, Aspergillus, Penicillium, Corollospora, Halosarpheia). Monitoring of species composition of myxomycetes is needed in farms that cultivate industrial objects, recreation sites, various buildings for prevention of mycotoxin intoxication and infestation by mycodermatoses and other diseases caused by opportunistic and pathogenic fungi.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Hidayatullah, Adietya Ramadhan, Fauziyah . et Fitri Agustriani. « PEMETAAN LOKASI HORSESHOE CRABS SEBAGAI PRIMITIVE ANIMAL DI PERAIRAN PESISIR BANYUASIN, PROVINSI SUMATERA SELATAN ». Maspari Journal : Marine Science Research 13, n^o 2 (4 novembre 2021) : 145–54. http://dx.doi.org/10.56064/maspari.v13i2.15771.

Texte intégral

Résumé :

Horseshoe crab atau disebut juga Belangkas atau mimi merupakan hewan primitif. Hewan ini keberadaannya di Indonesia termasuk hewan yang dilindungi. Pemetaan habitat Belangkas adalah salah satu cara untuk melindungi hewan tersebut dari ancaman kepunahan. Informasi ini dapat dijadikan baseline data untuk upaya konservasinya. Tujuan penelitian ini adalah memetakan lokasi Belangkas di perairan pesisir Banyuasin Sumatera Selatan menggunakan software Arcgis. Penelitian ini dilaksanakan pada bulan November-Desember 2019. Hasil identifikasi menunjukkan bahwa terdapat 2 jenis Belangkas yakni Tachypleus gigas dan Corcinoscorpius rotundicauda. Jenis C. rotundicauda paling banyak ditemukan dibandingkan T. Gigas. Kondisi perairan dikategorikan baik kecuali parameter DO. Belangkas sebagai primitive animal di perairan Banyuasin terdistribusi pada lokasi Daerah Tanjung Carat dan Upang. Biota ini ditemukan paling banyak berkumpul pada kedalaman 1-2 m dengan substrat lempung berpasir. Kata Kunci : Belangkas, Distribusi, Perairan Pesisir Banyuasin, Pemetaan

Styles APA, Harvard, Vancouver, ISO, etc.

32

Melo-Sampaio, Paulo R., et Pablo J. Venegas. « A new species of groundsnake genus Atractus Wagler, 1828 (Serpentes, Dipsadidae) from the Peruvian Andes revealed by unequivocal morphological characters ». Evolutionary Systematics 7, n^o 2 (9 août 2023) : 257–66. http://dx.doi.org/10.3897/evolsyst.7.102578.

Texte intégral

Résumé :

Based on an exhaustive revision of external morphological characters we describe a new species of Atractus from the humid montane forest of the Andes of northern Peru, Cajamarca department, occurring at elevations of 1641 to 2161 m. This new species was misidentified as A. gigas in the literature and for more than a decade represented the southernmost record of the that species. In the absence of molecular data and limited by a small sample, we use some underreported characters in the genus Atractus such as the presence of apical pits. Thus, the combination of apical pits as well as other characters mentioned in the literature (i.e., head scutellation and number of subcaudals) distinguishes the Peruvian population from A. gigas, and strongly supports the morphological separation of this taxon from the rest of its congeners.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Lisitskaya, Е. V., et S. V. Shchurov. « The first record of larval Crassostrea gigas ; (Thunberg 1793) (Bivalvia, Ostreidae) from the Black Sea ». Zoologičeskij žurnal 103, n^o 5 (8 novembre 2024) : 11–15. http://dx.doi.org/10.31857/s0044513424050028.

Texte intégral

Résumé :

Larvae of the oyster, Crassostrea gigas (Thunberg 1793) are being found in the plankton of the Black Sea for the first time. The studies were carried out in 2014–2023 along the Sevastopol coast. Samples were taken monthly with a Jeddy plankton net (inlet diameter 36 cm, mill gas mesh 135 µm). A water layer of 10–0 m was investigated. Live material was processed by total counting the larvae in the Bogorov chamber, using MBS-9 and Mikmed-5 light microscopes. Oyster larvae were recorded in August 2020 and observed in the plankton from the end of August to the beginning of October. They were also found in the waters at Miskhor, southern coast of Crimea in August 2023. The density of larvae amounted to 1–3 ind./m3. Larvae were found at the following water temperatures: minimum, 19.7 °C (September 2021), maximum, 26.6 °C (August 2022). In August, the larvae of C. gigas were at the stage of veliconch, their sizes ranging 275–340 mkm. The sizes of oyster larvae in September and October were 380 mkm, being already in the late stages of development. In the coastal waters of the northern part of the Black Sea, C. gigas larvae can settle on substrates from late August to mid-October.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Einsle, Ulrich K. « Megacyclops magnus (Marsh, 1920) (Crustacea, Copepoda) in northern Canada, a comparison with European Megacyclops species ». Canadian Journal of Zoology 71, n^o 7 (1 juillet 1993) : 1434–38. http://dx.doi.org/10.1139/z93-198.

Texte intégral

Résumé :

Megacyclops magnus (Marsh, 1920) is redescribed using morphological criteria. A morphometric comparison with European Megacyclops species confirms the validity of this well-characterized species, which has often been synonymized with M. gigas. The relative proportions of the apical spines on the last segment of the P4 endopodite (the inner one being shorter than the outer one) are unique within the genus.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Stelck, C. R. « Foraminifera of the middle to upper Albian transition (Lower Cretaceous), northeastern British Columbia ». Canadian Journal of Earth Sciences 28, n^o 4 (1 avril 1991) : 561–80. http://dx.doi.org/10.1139/e91-050.

Texte intégral

Résumé :

Throughout Alberta and Saskatchewan, the upper Albian Substage lies unconformably on subjacent beds. However, on the Peace River in northeastern British Columbia, 32 km below Hudson Hope, a silty shale outcrop shows uninterrupted marine deposition across the Middle–Upper Albian substage boundary. An arenaceous foraminiferal fauna of 21 genera and 57 sub-generic taxa is illustrated from this outcrop of the Hasler Shale. The collections come from above the previously illustrated microfauna of the Stelckiceras liardense Zone and below the occurrence of Haplophragmoides gigas gigas and provide a spectrum of transitional faunules spanning the middle–upper Albian boundary. The corresponding boundary of the Ammobaculites wenonahae Subzone of the Gaudryina nanushukensis Zone with the overlying Haplophragmoides uniorbis Subzone (new) at the base of the Haplophragmoides gigas Zone is defined at 73 m above the top of the Cadotte Sandstone by the disappearance of A. wenonahae. Genera within the upper part of the A. wenonahae Subzone and the H. uniorbis Subzone include Bathysiphon, Saccammina, Pelosina, Hippocrepina, Psammosphaera, Thuramminoides, Ammodiscus, Miliammina, Psamminopelta, Reophax, Scherochorella, Haplophragmoides, Ammobaculites, Bulbophragmium, Ammobaculoides, Textulariopsis, Pseudobolivina, Trochammina, Gravellina, Eggerella, and Verneuilinoides. Two new species and two new subspecies are established, viz. Ammobaculites kokei, Trochammina bredini, Haplophragmoides gigas Cushman pregigas, and Reophax deckeri Tappan sliteri. Species originally described from the upper Albian of Wyoming, such as Haplophragmoides uniorbis Eicher, originated out of boreal stock, as they are recognized within the middle Albian upper A. wenonahae Subzone north of the Peace River Arch. On the Peace River, the passage from middle Albian to upper Albian is marked by water depth at or below wave base, but regression is reflected at the substage boundary by the sharp reduction in variety of taxa.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Freire, Renan Passos, Jorge Enrique Hernandez-Gonzalez, Eliana Rosa Lima, Miriam Fussae Suzuki, João Ezequiel de Oliveira, Lucas Simon Torai, Paolo Bartolini et Carlos Roberto Jorge Soares. « Molecular Cloning and AlphaFold Modeling of Thyrotropin (ag-TSH) From the Amazonian Fish Pirarucu (Arapaima gigas) ». Bioinformatics and Biology Insights 17 (janvier 2023) : 117793222311541. http://dx.doi.org/10.1177/11779322231154148.

Texte intégral

Résumé :

Arapaima gigas, known as Pirarucu in Brazil, is one of the largest freshwater fish in the world. Some individuals could reach 3 m in length and weight up to 200 kg. Due to extinction risks and its economic value, the species has been a focus for preservation and reproduction studies. Thyrotropin (TSH) is a glycoprotein hormone formed by 2 subunits α and β whose main activity is related to the synthesis of thyroid hormones (THs)—T3 and T4. In this work, we present a combination of bioinformatics tools to identify Arapaima gigas βTSH (ag-βTSH), modeling its molecular structure and express the recombinant heterodimer form in mammalian cells. Using the combination of computational biology, based on genome-related information, in silico molecular cloning and modeling led to confirm results of the ag-βTSH sequence by reverse transcriptase-polymerase chain reaction (RT-PCR) and transient expression in human embryonic kidney (HEK293F) cells. Molecular cloning of ag-βTSH retrieved 146 amino acids with a signal peptide of 21 amino acid residues and 6 disulfide bonds. The sequence has a similarity to 39 fish species, ranging between 43.1% and 81.6%, whose domains are extremely conserved, such as cystine knot motif and N-glycosylation site. The Arapaima gigas thyrotropin (ag-TSH) model, solved by AlphaFold, was used in molecular dynamics simulations with Scleropages formosus receptor, providing similar values of free energy ΔGbind and ΔGPMF in comparison with Homo sapiens model. The recombinant expression in HEK293F cells reached a yield of 25 mg/L, characterized via chromatographic and physical-chemical techniques. This work shows that other Arapaima gigas proteins could be studied in a similar way, using the combination of these techniques, recovering more information from its genome and improving the reproduction and preservation of this prehistoric fish.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Pereira-Filho, Manoel, Bruno Adan Sagratzki Cavero, Rodrigo Roubach, Daniel Rabello Ituassú, André Lima Gandra et Roger Crescêncio. « Cultivo do Pirarucu (Arapaima gigas) em viveiro escavado ». Acta Amazonica 33, n^o 4 (décembre 2003) : 715–18. http://dx.doi.org/10.1590/s0044-59672003000400017.

Texte intégral

Résumé :

Foi avaliado o desempenho de juvenis de pirarucu em criação intensiva em viveiros escavados. Oitenta e cinco peixes com peso médio inicial de 133,3 ± 1,3g foram estocados em dois viveiros de 120m² cada (densidade de 1 peixe/3m²), com profundidade média de 1m e alimentados duas vezes ao dia (9:00 e 14:00h) com ração extrusada para peixes carnívoros contendo 40% de proteína bruta. Foi verificado diariamente o consumo de ração, enquanto mensalmente os peixes foram amostrados para a realização de biometrias com a finalidade de verificar seu desempenho em peso e comprimento. Após 12 meses de cultivo os peixes atingiram peso médio de 7,0 ± 1,1kg, comprimento total de 88,2 ±6,4cm, com conversão alimentar de 1,5 e produtividade de 2,5kg/m². Estes resultados mostram o grande potencial do pirarucu para a piscicultura intensiva na Amazônia.

Styles APA, Harvard, Vancouver, ISO, etc.

38

OLIVEIRA, Hyago Jovane Borges de, Adriana Ferreira LIMA, Lorhane Caroline Ferreira da LAPA, Hygo Jovane Borges de OLIVEIRA, Flávia Tavares de MATOS et Alex Pires de Oliveira NUÑER. « Effect of natural food consumption on the first phase of pirarucu grow-out in ponds and cages ». Acta Amazonica 53, n^o 1 (mars 2023) : 32–41. http://dx.doi.org/10.1590/1809-4392202201041.

Texte intégral

Résumé :

ABSTRACT Pirarucu, Arapaima gigas is a fish species of great social and economic importance in the Amazon region, where they are often farmed in earthen ponds. Intensive cage aquaculture has been growing in Brazil, which could be an alternative means to farm pirarucu, reducing costs and increasing productivity. We evaluated the contribution of natural food organisms in semi-intensive (ponds) and intensive (cages) production systems, and their effect on pirarucu growth and economic performance during the first phase of grow-out. Four ponds (300 m2) and four cages (4.0 m³) were stocked, respectively, with 120 (0.4 fish m-²) and 160 (40 fish m-³) juvenile pirarucu (28.03 ± 6.34 g, 11.75 ± 0.80 cm). The study was conducted for 105 days and fish were fed with commercial feed. Fish growth and plankton intake were evaluated every two weeks. Survival rate, standard length, weight gain and final weight were higher in fish reared in earthen ponds than in cages. Feed conversion of fish kept in ponds was lower (0.96 ± 0.06) than in cages (1.20 ± 0.11). The consumption of natural food organisms was observed, despite artificial feed being fed in both systems. The relative abundance of zooplankton and insects in stomachs was directly proportional to fish weight gain in ponds, and inversely proportional in cages. Higher economic efficiency rate and lower average production cost were calculated for earthen ponds. Our results indicate that the cost-benefit of the first phase grow-out of A. gigas is better in earthen ponds.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Aguirre-Macedo, M. L., et C. R. Kennedy. « Diversity of metazoan parasites of the introduced oyster species Crassostrea gigas in the Exe Estuary ». Journal of the Marine Biological Association of the United Kingdom 79, n^o 1 (février 1999) : 57–63. http://dx.doi.org/10.1017/s002531549800006x.

Texte intégral

Résumé :

Temporal patterns in metazoan parasite community diversity of Crassostrea gigas, (Lamellibranchia: Ostreidae) were studied in the Exe Estuary at monthly intervals over one year and in relation to host age-classes. A total of four metazoan species was found to parasitize C. gigas in the Exe Estuary: the turbellarian Paravortex sp., cercaria Lepocreadiidae, metacercariae of Renicola roscovita and the copepod Mytilicola intestinalis. Only R. roscovita and M. intestinalis were present in all months throughout the year and in all host age-classes. Analysis of the metazoan parasite community at individual host level revealed little variation in community structure with respect to season or host age, as only a slight increase in diversity values was observed during the summer months. However, community diversity does vary from year to year, as shown by comparison between host age group samples in three consecutive years. None of the parasites are specialist to oysters but all appear to be widespread and abundant parasite of other lamellibranch species.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Cavero, Bruno Adan Sagratzki, Manoel Pereira-Filho, André Moreira Bordinhon, Flávio Augusto Leão da Fonseca, Daniel Rabello Ituassú, Rodrigo Roubach et Eduardo Akifumi Ono. « Tolerância de juvenis de pirarucu ao aumento da concentração de amônia em ambiente confinado ». Pesquisa Agropecuária Brasileira 39, n^o 5 (mai 2004) : 513–16. http://dx.doi.org/10.1590/s0100-204x2004000500015.

Texte intégral

Résumé :

O objetivo deste trabalho foi avaliar a tolerância de juvenis de pirarucu, Arapaima gigas, a concentrações crescentes de amônia na água. Oito peixes (2,6±0,4 kg e 70,5±4,1 cm de comprimento) foram distribuídos aleatoriamente em quatro tanques (0,8x0,9x2,6 m) com 410 L de água tamponada com Na2PO4 e HCl, ambos a 0,1 M, onde ficaram por 33 dias. As concentrações de amônia no plasma sanguíneo dos peixes e na água foram determinadas pelo método do salicilato. A glicose plasmática e os níveis de amônia aumentaram proporcionalmente à concentração de amônia na água. Juvenis de pirarucu toleram altas concentrações de amônia na água.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Podolskaya, M., E. Chelebieva, O. Gostyukhina, D. Lavrichenko et E. Kladchenko. « FUNCTIONAL STATUS OF MAGALLANA GIGAS INFECTED BY PIONE VASTIFICA ». Russian Journal of Biological Physics and Chemisrty 8, n^o 3 (27 mai 2024) : 353–57. http://dx.doi.org/10.29039/rusjbpc.2023.0633.

Texte intégral

Résumé :

Pacific oyster Magallana gigas (Thunberg, 1793) is an important commercial species of the Black Sea coast of Russia. Black Sea is favorable for the development of regional mariculture, but the existing biotic factors may lead to damage to an oyster farm. In particular, boring sponge Pione vastifica (Hancock, 1849). Boring sponges are a serious problem for mariculture farms, because the affected mussels are withdrawn from trade, which entails economic losses. In this work, the effect of boring sponges on the functional state of hemocytes (the ability to produce reactive oxygen species - ROS and the membrane potential of mitochondria) and the antioxidant status of the mantle of the Pacific oyster were studied. The membrane potential of mitochondria was significantly inhibited in the hemocytes of mollusks affected by P. vastifica. In addition, the hemocytes of “infected” oysters were characterized by a higher level of ROS production compared to the group of “healthy" oysters. The increase in ROS was not accompanied by an increase in catalase activity. The absence of an increase in catalase activity against the background of excessive ROS production can lead to various physiological and metabolic disorders and a decrease in the growth rate of mollusks. The present study contributes to the expansion of understanding about the influence of the drilling sponge (P. vastifica) on the functional state of a common object of regional mariculture – the Pacific oyster (M. gigas).

Styles APA, Harvard, Vancouver, ISO, etc.

42

Hughes, D. J., S. J. Marrs, C. J. Smith et R. J. A. Atkinson. « Observations of the echiuran worm Bonellia viridis in the deep basin of the northern Evoikos Gulf, Greece ». Journal of the Marine Biological Association of the United Kingdom 79, n^o 2 (avril 1999) : 361–63. http://dx.doi.org/10.1017/s0025315498000411.

Texte intégral

Résumé :

Towed underwater TV observations at 440 m in the northern Evoikos Gulf, Greece, revealed a soft mud plain heavily bioturbated by the thalassinidean Calocaris macandreae, with Callianassa subterranea and Nephrops norvegicus also present. Ejecta mounds and feeding traces indicated the presence of a large echiuran, provisionally identified as Maxmuelleria gigas. The locality also supported a dense population of a second echiuran, Bonellia viridis, a species not previously recorded as an inhabitant of sedimentary environments.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Koke, Kory R., et C. R. Stelck. « Foraminifera of a Joli Fou Shale equivalent in the Lower Cretaceous (Albian) Hasler Formation, northeastern British Columbia ». Canadian Journal of Earth Sciences 22, n^o 9 (1 septembre 1985) : 1299–313. http://dx.doi.org/10.1139/e85-134.

Texte intégral

Résumé :

The discovery of the arenaceous foraminifer Haplophragmoides gigas Cushman in the Hudson Hope area of northeastern British Columbia indicates that the Early Cretaceous (Albian) Joli Fou Sea flooded around the north side of the Peace River Arch, making an embayment that penetrated as far west as the Rocky Mountain Foothills. The microfauna of 25 genera and 46 species of arenaceous foraminifers is illustrated carrying Bathysiphon spp., Hippocrepina sp., Hyperammina spp., Lituotuba? sp., Psammosphaera spp., Reophax spp., Ammodiscus spp., Glomospira sp., Miliammina spp., Psamminopelta spp., Trochamminoides sp., Haplophragmoides spp., Ammomarginulina sp., Ammobaculites spp., Haplophragmium spp., Trochammina spp., Textulariopsis sp., Pseudobolivina spp., Plectorecurvoides sp., Verneuilina sp., Gaudryina sp., Uvigerinammina sp., Gravellina sp., and Eggerella sp.The suite occurs in the lower part of the Hasler Shale of the Fort St. John Group about 10–20 m above beds carrying a microfauna of the Ammobaculites wenonahae Subzone (= Stelckiceras liardense ammonite Zone) present in the basal portion of the Hasler Shale. The Haplophragmoides gigas Zone sensu stricto is overlain by a sequence of silty beds (Viking equivalent?), which in turn is succeeded by the Miliammina manitobensis Zone microfauna. The H. gigas assemblage has both boreal and southern aspects, suggesting a mixing of the waters from north and south as the first expression of the Colorado Sea in earliest late Albian time. The assemblage is a deep neritic one and lacks any calcareous component. Diagnostic megafauna are lacking.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Sillanpää, J. Kirsikka, Henrik Sundh et Kristina S. Sundell. « Calcium transfer across the outer mantle epithelium in the Pacific oyster, Crassostrea gigas ». Proceedings of the Royal Society B : Biological Sciences 285, n^o 1891 (14 novembre 2018) : 20181676. http://dx.doi.org/10.1098/rspb.2018.1676.

Texte intégral

Résumé :

Calcium transport is essential for bivalves to be able to build and maintain their shells. Ionized calcium (Ca 2+ ) is taken up from the environment and eventually transported through the outer mantle epithelium (OME) to the shell growth area. However, the mechanisms behind this process are poorly understood. The objective of the present study was to characterize the Ca 2+ transfer performed by the OME of the Pacific oyster, Crassostrea gigas, as well as to develop an Ussing chamber technique for the functional assessment of transport activities in epithelia of marine bivalves. Kinetic studies revealed that the Ca 2+ transfer across the OME consists of one saturable and one linear component, of which the saturable component fits best to Michaelis–Menten kinetics and is characterized by a K m of 6.2 mM and a V max of 3.3 nM min −1 . The transcellular transfer of Ca 2+ accounts for approximately 60% of the total Ca 2+ transfer across the OME of C. giga s at environmental Ca 2+ concentrations. The use of the pharmacological inhibitors: verapamil, ouabain and caloxin 1a1 revealed that voltage-gated Ca 2+ -channels, plasma-membrane Ca 2+ -ATPase and Na + /Ca 2+ -exchanger all participate in the transcellular Ca 2+ transfer across the OME and a model for this Ca 2+ transfer is presented and discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Cavero, Bruno Adan Sagratzki, Manoel Pereira-Filho, Rodrigo Roubach, Daniel Rabello Ituassú, André Lima Gandra et Roger Crescêncio. « Biomassa sustentável de juvenis de pirarucu em tanques-rede de pequeno volume ». Pesquisa Agropecuária Brasileira 38, n^o 6 (juin 2003) : 723–28. http://dx.doi.org/10.1590/s0100-204x2003000600008.

Texte intégral

Résumé :

O objetivo deste trabalho foi estimar a biomassa sustentável de juvenis de pirarucu Arapaima gigas (Cuvier, 1829) mantidos em tanquesrede de pequeno volume. Durante 200 dias os peixes foram estocados em quatro tanques-rede de 1 m³, cada um com biomassa inicial total de 0,84±0,14 kg (21 peixes/tanque-rede). Os tanquesrede foram colocados em um viveiro de 50 m² com renovação constante de água. Os índices do fator de condição, da conversão alimentar, do crescimento específico e do ganho de biomassa revelaram que a biomassa sustentável de juvenis de pirarucu para a criação intensiva em tanques-rede de 1 m³ foi de aproximadamente 29 kg. O comprimento alcançado pelo peixe, no espaço reduzido do tanque-rede, é um fator limitante para manter bons índices zootécnicos.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Maafi, Z. Tanha, Z. Majd Taheri et S. A. Subbotin. « First Report of the Giant Stem Nematode, Ditylenchus gigas, from Broad Bean in Iran ». Plant Disease 97, n^o 7 (juillet 2013) : 1005. http://dx.doi.org/10.1094/pdis-01-13-0069-pdn.

Texte intégral

Résumé :

The giant stem nematode, Ditylenchus gigas (Nematoda: Tylenchida) has been recorded from several European and African countries mainly bordering the Mediterranean Sea (2). This nematode causes considerable yield loss of broad bean, Vicia faba, and it may induce more severe damage than the typical faba bean race of D. dipsaci. Spread of infestation through seed limits export of broad bean and has made these nematodes quarantine pests in many countries (2). Broad bean is cultivated in the north, west, southwest, and central parts of Iran. Although D. dipsaci has been reported from different crops and regions in Iran, there is no record of broad bean infection by this nematode. A survey of broad bean fields was conducted in the north and west provinces in a continuation of a study on different populations of D. dipsaci in Iran in May to July of 2007 and 2008 and resampling from some farms in June 2012. The sampling was performed at flowering stage and after. The aboveground plant samples were collected and cut into pieces of 2 to 3 cm, then incubated for 5 to 6 h in Whitehead trays. Morphological and molecular analysis of isolated nematodes from Kermanshah and Lorestan provinces revealed the presence of D. gigas in the samples. Of the 23 plant samples of cv. Barekat collected from Mazandaran and Golestan provinces in the north, 47.8% were infected with stem nematode, mostly with high population density of over 20,000 nematodes per 5 plant stems. The percentage of infected samples of broad bean cv. Shakhbozy collected in Lorestan and Kermanshah provinces in the west was 76.5%. The symptoms of infection were observed as necrotic lesions on the stem surface and reduction of internode distances in severe infection. The giant stem nematode population from Kermanshah showed the following characters: females (n = 20), L = 1,650 ± 140 (1,270 to 1,875) μm; b′ = 8.6 ± 0.6 (7.7 to 10.0), c = 19.0 ± 1.3 (19.2 to 21.2), c′ = 4.7 ± 0.5 (1.1 to 5.3), stylet = 11.6 ± 0.5 (11 to 12) μm; post vulval sac = 96 ± 16 (58 to 140) μm; vulval-anus distance = 217.0 ± 21.0 (178 to 272) μm, tail = 86.4 ± 9.4 (66 to 102) μm; males (n = 10), L = 1,495 ± 148 (1,236 to 1,636) μm; b′ = 7.7 ± 0.3 (7.3 to 8.1), c = 17.3 ± 0.7 (16.3 to 18.6), stylet = 11.3 ± 0.5 (11 to 12) μm, tail = 86.5 ± 8.5 (71 to 95) μm, spicules = 24.8 ± 1.7 (23 to 28) μm. The morphological and morpohometric features were generally in agreement with those published for D. gigas (2). The morphological identification of D. gigas from Iran was supported by the analyses of the ITS rRNA and the D2-D3 expansion segments of the 28S rRNA gene sequences. The rRNA gene of D. gigas from broad bean and D. dipsaci from garlic were amplified and sequenced using two primer sets: (i) the TW81 and AB28 for the ITS-rRNA and (ii) D2A and D3B for partly 28S rRNA gene, as described by (2). New sequences were deposited in the GenBank under accession numbers KC310732 through KC310735. The Iranian D. gigas sequences showed 100% similarity with those of the Italian D. gigas isolates (ITS rRNA: HQ219231, HQ219232; D2-D3 of 28S rRNA: HQ219217 and HQ219216). The identification was further supported by PCR with species specific SCAR (sequence characterized amplified region) primers for this species (1). The specimens from broad bean generated a specific fragment ∼200 bp for D. gigas, whereas the samples with D. dipsaci from garlic and alfalfa produced one fragment ∼250 bp specific for this species. To our knowledge, this is the first report of D. gigas from broad bean in Iran. References: (1) M. Esquibet et al. Genome 46:1077, 2003. (2) N. Vovlas et al. Plant Pathol. 60:762, 2011.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Augusteyn, John, Jane Hughes, Graeme Armstrong, Kathryn Real et Carlo Pacioni. « Tracking and tracing central Queensland’s Macroderma – determining the size of the Mount Etna ghost bat population and potential threats ». Australian Mammalogy 40, n^o 2 (2018) : 243. http://dx.doi.org/10.1071/am16010.

Texte intégral

Résumé :

The ghost bat, Macroderma gigas, colony at Mount Etna was at the centre of Australia’s longest-running conservation campaign. To protect the colony the Queensland Government removed recreational facilities and gated caves. The size and genetic diversity of the Mount Etna M. gigas population were estimated using cave searches, direct captures and molecular analysis to determine whether these actions have benefitted the species. In addition, telemetry was undertaken and red fox, Vulpes vulpes, scats analysed to identify possible threats. Results suggest that the population has declined by 79% since the late 1990s, has low microsatellite diversity, low effective population size (Ne) and is undergoing a population bottleneck. VHF- and GPS-collared animals were found to forage over agricultural land up to 11.8 km from their daytime roost, suggesting that poor land management and barbed-wire fences could be potential threats. No ghost bat remains were found in fox scats. We recommend that compliance be increased around Johansen’s Cave to reduce disturbance during the maternity season and landholders be encouraged to undertake management that is sympathetic to ghost bats.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Nasution, Aurora Khairani. « Fabrication and Characterization of Glucosamine Hydrochloride from Chitin of Horseshoe Crab Shell (Tachypleus gigas) ». Journal of Chemical Natural Resources 3, n^o 2 (24 août 2022) : 147–54. http://dx.doi.org/10.32734/jcnar.v3i2.9350.

Texte intégral

Résumé :

Preparation of glucosamine hydrochloride from the chitin of horseshoe crab shells using the chemical hydrolysis method has been done using HCl concentration variation ratios of 7%, 9%, 11%,14 % with a ratio of 9:1 (v/w) for 4 hours at a temperature of 90ºC. Determination of glucosamine hydrochloride characteristics was characterized using Fourier transform-infra red (FT-IR) spectroscopy, in which the characteristics of glucosamine hydrochloride obtained in the OH group of glucosamine hydrochloride were 3446 cm-1 (s), 3448 cm-1 (s), 3450 cm-1 (s), 3448 cm-1 (s), respectively. For NH group of glucosamine hydrochloride were 1557 cm-1 (s), 1559 cm-1 (s), 1556 cm-1 (s), 1560 cm-1 (s), respectively. For CN group of glucosamine hydrochloride were 1379 cm-1 (m), 1379 cm-1 (m), 1379 cm-1 (m), 1379 cm-1 (m), respectively. While the glycoside bond of glucosamine hydrochloride 1073 cm-1 (w), 1074 cm-1 (w), 1074 cm-1 (w), 1074 cm-1 (w), respectively. Determination of the concentration of glucosamine hydrochloride with Ultraviolet Spectrophotometer analysis at a maximum wavelength of 197 nm with a standard solution of N-acetyl glucosamine in a solution of phosphate acid 0.005%, in which obtained the concentration of glucosamine hydrochloride 7% = 33.67 ppm, 9% = 36.35 ppm, 11% = 40.16 ppm, 14% = 43.97 ppm.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Abed, A. El. « NOUVELLES INFORMATIONS SUR LES COPEPODES CALANOIDES ET CYCLOPOIDES DES EAUX CONTINENTALES TUNISIENNES ». Crustaceana 72, n^o 2 (1999) : 157–69. http://dx.doi.org/10.1163/156854099503258.

Texte intégral

Résumé :

AbstractDuring the period 1992-1996, eighteen species of Copepoda Cyclopoida and Calanoida have been recorded in Tunisian continental water samples from 56 localities. Six species were noticed for the first time in Tunisia, three of which are new records for northern Africa. Two species represent Ethiopian elements (Paradiaptomus greeni (Gurney, 1906) and Thermocyclops tchadensis Dussart & Gras, 1966) and there is one oriental species (Apocyclops royi (Lindberg, 1940)) while Eucyclops serrulatus (Fischer, 1851) and Megacyclops gigas (Claus, 1857) are cosmopolitan, and Halicyclops neglectus Kiefer, 1935 is rather palaearctic. The majority of cyclopoid and calanoid copepods has been taken in "oueds" (both temporary and permanent waters). In Tunisian continental waters, about ten species were found in each climatic area, though there are some species particular to humid and sub-humid areas (Copidodiaptomus numidicus (Gurney, 1909) and Arctodiaptomus wierzejskii (Richard, 1888)) in northern Tunisia. Calanipeda aquaedulcis (Kritschagin, 1873) and Metacyclops minutus (Claus, 1863) occur especially in semi-arid areas. M. minutus (Claus, 1863) and Metadiaptomus chevreuxi (De Guerne & Richard, 1889) were found in the arid areas, particularly in central Tunisia. Durant la periode 1992-1996, 18 especes de copepodes (Cyclopo des et Calano des) ont ete recoltees dans les eaux continentales tunisiennes. Cet inventaire fait etat de six especes qui sont nouvelles pour la Tunisie: Paradiaptomus greeni (Gurney, 1906), Thermocyclops tchadensis Dussart & Gras, 1966, Apocyclops royi Lindberg, 1940, Halicyclops neglectus Kiefer, 1935, Eucyclops serrulatus (Fischer, 1851) et Megacyclops gigas (Claus, 1857). Parmi ces especes, les trois premieres sont nouvelles pour l'Afrique du Nord. Les especes P. greeni et T. tchadensis sont deux elements ethiopiens, A. royi est une espece jusqu'alors seulement connue d'Asie (Inde, Chine). H. neglectus est une espece palearctique alors que M. gigas et E. serrulatus sont cosmopolites. Dans les eaux continentales tunisiennes, l'etude de la repartition des Copepodes Cyclopo des et Calano des en fonction des zones climatiques precedemment etablies conduisent aux resultats suivants: Copidodiaptomus numidicus (Gurney, 1909) et Arctodiaptomus wierzejskii (Richard, 1888) sont caracteristiques de la region humide a sub-humide, Calanipeda aquaedulcis (Kritschagin, 1873) et Metacyclops minutus (Claus, 1863) sont les elements principaux de la region semi-aride. M. minutus ainsi que Metadiaptomus chevreuxi (De Guerne & Richard, 1889) sont des especes plutot caracteristiques des regions arides du centre de la Tunisie.

Styles APA, Harvard, Vancouver, ISO, etc.

50

DIAS, Marcia Kelly Reis, Eliane Tie Oba YOSHIOKA, Anselmo Fortunato Ruiz RODRIGUEZ, Ricardo Amaral RIBEIRO, Caio Pinho FERNANDES, Rodrigo Otávio Almeida OZÓRIO et Marcos TAVARES-DIAS. « Mansoa alliacea extract improves the growth performance and innate immune response of Arapaima gigas challenged with Aeromonas hydrophila and handling stress ». Acta Amazonica 53, n^o 1 (mars 2023) : 24–31. http://dx.doi.org/10.1590/1809-4392202101231.

Texte intégral

Résumé :

ABSTRACT This study investigated the effects of dietary supplementation with Mansoa alliacea hydroalcoholic extracts on growth, blood and immune parameters of Arapaima gigas. Fish were fed for 30 days with diets enriched with 0, 4, 8, and 12 g kg-1 of M. alliacea hydroalcoholic extract and subjected to infection with Aeromonas hydrophila and handling stress. Fish fed with 8 g kg-1 of extract showed significant increase in final weight, specific growth rate and feed efficiency when compared to the other groups. Glucose, triglycerides, total proteins, and globulins increased significantly in fish fed with 8 g kg-1 of extract, whereas albumin decreased. The number of thrombocytes increased significantly with the dietary supplementation of 8 and 12 g kg-1 of extract. After the challenge with A. hydrophila and handling stress, fish fed with 8 g kg-1 of extract had significantly higher levels of glucose, globulins, and albumins, and fish fed with 8 and 12 g kg-1 of extract showed an increment of respiratory burst. Triglyceride levels dropped significantly in fish fed with 4, 8, and 12 g kg-1 of extract, whereas the number of neutrophils increased, and total thrombocytes, leukocytes and lymphocytes were higher in fish fed with 12 g kg-1 of extract. Dietary supplementation with M. alliacea extract at 8 g kg-1 was efficient in improving the growth and innate immunity of A. gigas, being potentially useful in fish farming to control the development of A. hydrophila infections.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « M. gigas »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres