Trophic relationships and use of area of two sympatric small cetaceans in the Southwestern Atlantic Ocean determined by carbon and nitrogen stable isotopes.

Autor: Campos LB; Laboratório de Biologia da Conservação de Mamíferos Aquáticos (LABCMA), Departamento de Oceanografia Biológica, Instituto Oceanográfico da Universidade de São Paulo (USP), Praça do Oceanográfico, 191, Cidade Universitária, Butantã, 05508-120 São Paulo, SP, Brazil., Santos MCO; Laboratório de Biologia da Conservação de Mamíferos Aquáticos (LABCMA), Departamento de Oceanografia Biológica, Instituto Oceanográfico da Universidade de São Paulo (USP), Praça do Oceanográfico, 191, Cidade Universitária, Butantã, 05508-120 São Paulo, SP, Brazil.
Jazyk: angličtina
Zdroj: Anais da Academia Brasileira de Ciencias [An Acad Bras Cienc] 2021 May 31; Vol. 93 (2), pp. e20200638. Date of Electronic Publication: 2021 May 31 (Print Publication: 2021).
DOI: 10.1590/0001-3765202120200638
Abstrakt: As cetaceans are sentinels of the marine environment, studying their life history is of utmost importance in understanding their habits and their interaction with the environment. To achieve this goal, it is important to study their ecological niches through the investigation of their habitat use patterns and trophic relationships. This study aimed to evaluate if there are differences in the habitat use patterns and the trophic ecology of franciscana (Pontoporia blainvillei) and Guiana dolphins (Sotalia guianensis) accidentally caught off the south coast of São Paulo State, and Guiana dolphins biopsied in the Cananeia estuary, southeastern Brazil, based on the carbon and the nitrogen stable isotopes analysis. Isotopic ratios were estimated from skin samples. The isotopic niche size and overlap were calculated using the SIBER package (R software). The gathered results showed evidence of spatial segregation between Guiana dolphins and franciscanas. The Guiana dolphins sampled inside and outside the estuary showed evidence of trophic and spatial segregation. No difference in isotopic values between sexes was found for both species. Such differences between franciscanas and Guiana dolphins were expected as both species have distinct life histories as a result of different evolutionary pathways.
Databáze: MEDLINE