Resumen del producto

Rhizoprionodon longurio is a coastal species of high economic value for the fishing communities of the Mexican Pacific, where Bahia de La Paz is a breeding area for this species. Several authors have analyzed their diet through techniques such as stomach content analysis and stable isotopes in muscle. These methods have provided results that differ in the literature by proposing R. longurio as a generalist or specialist predator, with differences in preys and behaviors. The objective of this study is to determine the possible ontogenic and gender differences in their trophic ecology, based on the analysis of stomach contents and stable isotopes in muscle and vertebrae. Where the latter represent the isotopic variation of the diet throughout the life of the organism. Thirty stomachs were analyzed, of which 15 were empty. The most important preys were determined using the Index of Relative Importance Specific Prey, as well as Bayesian mixing models for stable isotopes. The Bayesian ellipses model (SIBER) was used to determine the possible differences between sexes. Previous results indicate that Scomber japonicus is the most important item in the diet, while the P. vannamei and the Ophidiidae family are the ones with the greatest isotopic contribution. However, none of the dams is dominant according to the Amundsen chart, added to a Levin index of 0.6 and variance values of d15N> 1 confirm the general trend of this species. Slight differences in diet between sexes were determined by the SIBER method for isotopes in muscle with an intermediate overlap of 0.46 (<0.6). The trophic position for isotopes was 3.5. The isotope analysis in vertebrae will be performed and stomach tests will continue to determine possible ontogenetic changes in the diet.

Palabras clave: ecología trófica; isótopos estables en vértebras; tiburones

Para obtener una copia del documento contacta la personal de la biblioteca a través del correo bibliocicimar{a}ipn.mx