A review of the ecological role of the Neotropical freshwater stingrays (Chondrichthyes: Potamotrygoninae)

Author(s)

Shibuya, Akemi

• Document type: Journal article
• Source: FOOD WEBS; v. 32, p. 8-pg., 2022-07-06.

Abstract

The freshwater stingrays of the subfamily Potamotrygoninae occupy a variety of habitats in Neotropical rivers, where they feed primarily on benthic prey. Prior work on these stingrays have described the composition of their diets and feeding habits, but have provided few insights into the relationship between prey choice and prey availability. Given this, a comprehensive review of the diet and trophic interactions in potamotrygonines is needed to help understand the ecological role of these stingrays in freshwater environments. In the present study, I consulted material published in scientific journals and gray literature to compile information on the composition of the diet. When possible, I included both qualitative and quantitative parameters, the Relative Importance (%IRI) and Alimentary indices (%IAi). Potamotrygonin stingrays are found in an enormous diversity of habitats, and many studies have identified them as mesopredators, with a diet composed primarily of mollusks, decapods, insects, and fishes. Although few organisms are known to prey on stingrays, they do not appear to be apex predators, but rather, mesopredators with a low predation risk. Fluctuations in prey availability related to the annual flood pulse of the rivers were reflected in dietary overlap in some studies, although these findings do not necessarily indicate competition for food. There is a clear knowledge gap for most species and populations of freshwater stingrays, and this review provides the first systematic insights into the variation in the diet and predator-prey interactions of the potamotrygonines. (AU)

• FAPESP's process: 11/23683-0 - A comparative morphological study of the feeding mechanism in rays of the order Myliobatiformes (Chondrichthyes: Batoidea)
• Grantee: Akemi Shibuya
• Support Opportunities: Scholarships in Brazil - Post-Doctoral