Effect of host phylogeny in the taxonomic composition and assemblage of the epidermal microbiome in elasmobranchs across geographic locations

The microbial community associated with living organisms plays a crucial role in host health and survival, but its role and composition remain widely understudied, especially in elasmobranchs. Previous research suggests that the skin microbiome of elasmobranchs is distinct from the surrounding water microbial community and also host-specific, harboring a phylogenetic signal and selecting for the microbiome. We studied the epidermal microbiome taxonomic composition and diversity of fourteen elasmobranch species from different geographic locations and captivity status employing data sets acquired from the NCBI that used high throughput DNA sequencing of the 16S rRNA V4 region. We hypothesized that our results would be adjusted to a phylosymbiotic pattern as previously suggested in the scientific literature. Results were consistent with previous findings with the biological samples from the elasmobranch epidermis being different than the environmental samples from seawater. Epidermal microbiomes were also species-specific, and some similarities were found in host species belonging to the same taxonomic order, suggesting a phylosymbiotic pattern with the taxonomic composition of the epidermal microbiome being driven by host phylogeny. We studied the effect of geographic location and captivity status on the microbiome taxonomic composition. Results showed that the core microbiome, composed of the highly abundant microbial taxa that perform key functions, seems to be conserved across locations and less prevalent or more transient species are influenced by location. Captivity status influenced the microbiome of Aetobatus narinari and Rhincodon typus, but further research is needed. This research sheds light on the several processes and factors that intervene in the epidermal microbiome assemblage and inheritance in elasmobranchs, highlighting the microbial taxonomic composition and diversity for each host species and its core microbiome and the processes behind their acquisition by the host, ultimately aiding in the interpretation of the symbiotic relationships and the eco-evolutionary processes that conform the elasmobranch epidermal microbiome

Fish length-weight relationships in the Weddell Sea and Bransfield Strait

Length-weight relationships are provided for 49 Antarctic fishes from 9 families. The fish were from three research cruises of 1996, 1998 and 2000 to the Weddell Sea and Antarctic Peninsula. Samples were collected by benthopelagic net, Agassiz trawl and bottom trawl at depths of 200-2,300 m. The exponent b in the length-weight relationship W = aLb ranged from 2.53 to 4.05. With a mean of 3.33, 50% of the values ranged between 3.157 and 3.480. In 31 species, the parameters were determined for each sex. For 64.5% of species, b was higher in females than in males. Exceptions were the Channichthyidae where b for six species was higher for males.Peer Reviewe

La pesca de los costeros canarios en el banco sahariano: antecedentes historicos y situacion actual La chopa, Spondyliosoma catharus (Linnaeus, 1758), como ejemplo de aplicacion de metodos simples para la evaluacion de stocks

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

Analyse de la fiabilité des statistiques des pêcheries maritimes artisanales togolaises générées par la méthode ARTFISH de la FAO

Objectif : L’objectif de la présente étude est d’évaluer la précision et l’exactitude des données sur les indicateurs des pêcheries artisanales maritimes togolaises en vue de leur utilisation en connaissance de cause.Méthodologie et résulta : La collecte et le traitement des données primaires sur les variables de ces pêcheries (effort de pêche, captures, CPUE, etc.) s’effectuent depuis 1999 suivant un programme d’enquêtes utilisant un logiciel. Les deux éléments sont connus sous le nom de "ARTFISH". Les données secondaires mensuelles de variabilité générées à l’aide d’ARTFISH (niveaux d’exactitude, coefficients de variation et coefficients d’activité pirogue) et stockées de 1999 à 2012 dans une base à la Direction des pêches du Togo (DPA) sont extraites à 38,55% par échantillonnage et évaluées à partir des tests statistiques et de l’analyse en composantes principales (ACP). Les résultats obtenus montrent que les estimations de l’effort de pêche et des captures sont respectivement exactes à 96,94% et 85,71% et précises à 95,92% et 57,14% et ; celles de la CPUE sont précises à 72,45%. Les forts coefficients de variation qui se situent entre 16,65 et 36,90% s’expliqueraient par l’hétérogénéité observée souvent dans les débarquements des captures. Le coefficient d’activité pirogue variant de 29,53 à 70,09% dépasse 100% de juillet à décembre surtout sur le site « Port de pêche» et les pêcheries de la senne tournante.Conclusion et application des résultats : Il est retenu que les estimations de l’effort de pêche, des captures, de la CPUE, etc. des pêcheries artisanales maritimes du Togo sont fiables au moins à 57,14% des échantillons. Toutefois, les forts coefficients de variation estimés à 42,86% des échantillons et attribuables à l’hétérogénéité des débarquements des captures, montreraient la rareté des ressources halieutiques des eaux togolaises. Ainsi, les estimations des indicateurs des pêcheries artisanales maritimes du Togo peuvent-elles être utilisées sans trop de restrictions.Mots clés : Togo, pêcheries artisanales maritimes, ARTFISH, estimations, données, précision, exactitude

A comparative study of the diet of Loligo vulgaris (Lamarck, 1799) (Mollusca:Cephalopoda) from the south coast of Portugal and the Saharan Bank (Central-East Atlantic)

This paper presents data on the diet of the squid, Loligo vulgaris (Lamarck, 1799) from the south coast of Portugal (Algarve) and from the Saharan Bank (Central-East Atlantic). A total of 964 squid was collected from the Algarve coast, between March 1993 and October 1994, from bottom trawling. An additional sample of 70 stomachs was obtained in the Algarve coast from the hand jigging fishery during 1991 and 1992. In the Saharan Bank, 848 squid were obtained, between June 1993 and January 1994, with bottom trawling. Stomachs with contents for trawled squid from the Algarve coast, and the Saharan Bank represented 28.1% and 40.8%, respectively. Fish was always the main component of the diet in both regions, representing 88.6% of the total weight of the prey found in the stomachs, for the Algarve coast, and 70.9% for the Saharan Bank. The occurrence percentage and the percentage in number indicated that Trachurus trachurus and fish belonging to the family Gobiidae were the most frequent fish found in the Algarve samples, while flatfish were the most common fish in the Saharan Bank samples. Loligo vulgaris was the dominant cephalopod found in the stomachs for both regions. No differences in the diet were found between males and females. The comparison between immature and mature squid showed that the importance of fish was higher in mature squid, for both regions. The squid captured from the Algarve coast by bottom trawling (at greater depths and offshore) fed primarily on fish, while those captured with hand jigging (inshore, at lower depths) contained an important percentage of crustaceans

Diagnostic de l'etat du stock de poulpe (Octopus vulgaris) mauritanien : synthese et nouvelles evaluations par approche globale

Diagnostic de l'etat du stock de poulpe (Octopus vulgaris) mauritanien : synthese et nouvelles evaluations par approche global

Resultados de la campaNa experimental de pesca, realizada en aguas del Suroeste de la Isla de Tenerife, Canarias 9206

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai