Bisi Tatiana Lemos, Dorneles Paulo Renato, Lailson-Brito José, Lepoint Gilles, Azevedo Alexandre de Freitas, Flach Leonardo, Malm Olaf, Das Krishna
Laboratório de Mamíferos Aquáticos e Bioindicadores "Profa. Izabel Gurgel" (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil ; Programa de Pós-Graduação em Ecologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil ; Laboratório de Radioisótopos Eduardo Penna Franca, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
Laboratório de Radioisótopos Eduardo Penna Franca, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
PLoS One. 2013 Dec 16;8(12):e82205. doi: 10.1371/journal.pone.0082205. eCollection 2013.
To investigate the foraging habitats of delphinids in southeastern Brazil, we analyzed stable carbon (δ(13)C) and nitrogen (δ(15)N) isotopes in muscle samples of the following 10 delphinid species: Sotalia guianensis, Stenella frontalis, Tursiops truncatus, Steno bredanensis, Pseudorca crassidens, Delphinus sp., Lagenodelphis hosei, Stenella attenuata, Stenella longirostris and Grampus griseus. We also compared the δ(13)C and δ(15)N values among four populations of S. guianensis. Variation in carbon isotope results from coast to ocean indicated that there was a significant decrease in δ(13)C values from estuarine dolphins to oceanic species. S. guianensis from Guanabara Bay had the highest mean δ(13)C value, while oceanic species showed significantly lower δ(13)C values. The highest δ(15)N values were observed for P. crassidens and T. truncatus, suggesting that these species occupy the highest trophic position among the delphinids studied here. The oceanic species S. attenuata, G. griseus and L. hosei had the lowest δ(15)N values. Stable isotope analysis showed that the three populations of S. guianensis in coastal bays had different δ(13)C values, but similar δ(15)N results. Guiana dolphins from Sepetiba and Ilha Grande bays had different foraging habitat, with specimens from Ilha Grande showing more negative δ(13)C values. This study provides further information on the feeding ecology of delphinids occurring in southeastern Brazil, with evidence of distinctive foraging habitats and the occupation of different ecological niches by these species in the study area.
为了调查巴西东南部海豚的觅食栖息地，我们分析了以下10种海豚物种肌肉样本中的稳定碳（δ(13)C）和氮（δ(15)N）同位素：圭亚那海豚、额斑原海豚、宽吻海豚短吻亚种、糙齿海豚、侏虎鲸、海豚属、霍氏海豚、热带点斑原海豚、长吻原海豚和灰海豚。我们还比较了圭亚那海豚四个种群之间的δ(13)C和δ(15)N值。从海岸到海洋碳同位素的变化表明，从河口海豚到海洋物种，δ(13)C值显著降低。瓜纳巴拉湾的圭亚那海豚平均δ(13)C值最高，而海洋物种的δ(13)C值显著较低。糙齿海豚和宽吻海豚短吻亚种的δ(15)N值最高，表明这些物种在此研究的海豚中占据最高营养级。海洋物种热带点斑原海豚、灰海豚和霍氏海豚的δ(15)N值最低。稳定同位素分析表明，沿海海湾的三个圭亚那海豚种群具有不同的δ(13)C值，但δ(15)N结果相似。塞佩蒂巴湾和大伊利亚湾的圭亚那海豚有不同的觅食栖息地，大伊利亚湾的样本显示出更负的δ(13)C值。这项研究提供了关于巴西东南部海豚觅食生态的更多信息，证明了这些物种在研究区域有独特的觅食栖息地并占据不同的生态位。
