Diet variation of the South American snake-necked turtle (Hydromedusa tectifera) from two different urban neighboring streams

SANCHEZ RM; SEMEÑIUK MB; CASSANO MJ; ALCALDE L

NORTH-WESTERN JOURNAL OF ZOOLOGY

UNIV ORADEA PUBL HOUSE

Lugar: Oradea, Rumania; Año: 2021 vol. 17 p. 212 - 219

1584-9074

Dietary studies provide data about the biology of species such as food specialization, spatial and temporal feeding variation and also adaptation to different habitat characteristics. In this work we analyzed the diet of the South American snake-necked turtle Hydromedusa tectifera employing complementary techniques (stomach flushing and feces collection) from two populations inhabiting quite different urban watercourses in La Plata city (Buenos Aires, Argentina). We calculated the Index of Relative Importance (IRI) to assess the contribution of each prey to the diet and the Index of Electivity (E) to evaluate food selection. In the main, studied populations of Hydromedusa tectifera displayed a generalist carnivorous habit with clear adaptations to variances in the environments this species lives. We obtained marked differences in the diet composition between streams: in the most impacted watercourse, amphipods, aquatic coleopterans and water bugs family Belostomatidae were the main items, while at the less disturbed one, aquatic snails dominated the diet of the species. Finally, our results highlight the importance to combine stomach flushing and fecal collection techniques to achieve a better trophic characterization and to avoid biased conclusions.