Variación en los parámetros fisiológicos yvalores isotópicos en sangre del tiburón demersal Scyliorhinus canicula (Linnaeus, 1758) en relación a la estación del año, al sexo y al estado de madurez

Trabajo final presentado por Elisenda Valls Mateus para el Máster en Biodiversidad, realizado bajo la dirección del Dr. Joan Josep Navarro Bernabé y de Claudio Barría Oyarzo del Institut de Ciències del Mar (ICM-CSIC).-- 26 pages, 7 figures, 3 tablesMarine predators such elasmobranchs exhibit variations in nutritional requirements related to reproductive traits or conditioned by variations in food availability in the marine environment throughout the year. In this study, the main objective was to examine how certain physiological parameters and stable isotope values in blood of demersal shark Scyliorhinus canicula in the wild change in relation to season, sex and maturity stage change. For this purpose, plasma lipid fractions (cholesterol, triglycerides, phospholipids), a ketone body metabolite (3-hydroxybutyrate) and isotopic values of N and C in blood of Scyliorhinus canicula individuals captured and released alive in the Western Mediterranean were analyzed. The results indicated that the isotopic values changed between summer and winter, males and females and mature and immature individuals. In relation to the physiological parameters we found that during summer triglycerides and phospholipids values were lower in mature individuals (especially in females, probably due to breeding season and laying eggs) and higher in immature specimens, indicating a higher physical activity than in winter. Cholesterol showed high values in summer, probably related to the reproduction. In the case of 3-hydroxybutyrate, the observed pattern was different from the other physiological parameters. Mature males showed higher values than other individuals during the winter season, indicating some physical activity, both mature and immature males showed higher values of this parameter in comparison to females during winter. During summer we found no differences by sex or maturity stage in the values of this metabolite. This study uses an innovative analysis of stable isotopes and plasma lipid fractions in the blood, without causing further damage to the target species. With this methodology new information regarding trophic ecology and physiological state of an abundant elasmobranch is providedEste trabajo de fin de máster es una contribución dentro del proyecto ECOTRANS (CTM2011-26333, Ministerio de Economía y Competitividad del Gobierno Español)Peer Reviewe

Seasonal, ontogenetic and sexual variations of physiological parameters in the small-spotted catshark (Scyliorhinus canicula) in the deep-sea freeliving conditions

VI Congreso Ibérico de Ictiología - VI Iberian Congress of Ichthyology (SIBIC2016), celebrado del 21 al 24 de junio de 2016 en Murcia.-- 1 pageMarine predators, such as elasmobranchs, exhibit variations in nutritional conditions related to both reproductive traits and food availability in the marine environment throughout the year. The main objective of this study was to examine changes in several blood physiological parameters in a demersal shark, the small-spotted catshark (Scyliorhinus canicula), in the wild in relation to season, sex and maturity stage. For this purpose, 108 individuals at different developmental stages were captured and released alive in the Western Mediterranean. Blood was obtained from caudal vessels and plasma lipid fractions (total cholesterol, triglycerides and phospholipids) and a ketone body (3-ß-hydroxybutyrate) were measured. During summer, plasma triglyceride and phospholipid levels were lower in adults than in juveniles (mainly in females, probably related to breeding season and laying eggs). Plasma cholesterol levels also showed higher values in summer, indicating higher physical activities during summer and revealing that lipid fractions are more related to reproduction than to nutrition. Plasma 3-ß-hydroxybutyrate variations showed a different pattern. No differences were found between sex or maturity stage during summer, although the highest values in adult and juvenile males during winter indicates higher physical activity of males. This study, uses an innovative methodology to establish a correlation between lipid fractions and ketone bodies from the blood of wild individuals and changes in sexual and nutritional status. This method was conducted without damage to the target species and provides new information on the physiology of this abundant elasmobranch in the Mediterranean SeaPeer Reviewe

Ecophysiology of the small-spotted catshark in free-living conditions

VI Congreso Ibérico de Ictiología - VI Iberian Congress of Ichthyology (SIBIC2016), celebrado del 21 al 24 de junio de 2016 en Murcia.-- 3 pages, 1 figurePeer Reviewe

The ECOTRANS Project: unraveling the trophic pathways and energy transfer from small pelagic fish to top predators in the Mediterranean Sea

Peer Reviewe