Insectivory in Potamotrygon signata (Chondrichthyes: Potamotrygonidae), an endemic freshwater stingray from the Parnaíba River basin, northeastern Brazil/Insetivoria em Potamotrygon signata (Chondrichthyes: Potamotrygonidae), uma raia de água doce endêmica da bacia do rio Parnaíba, nordeste do Brasil

• Published in: Brazilian journal of biology Vol. 72; no. 4; p. 885
• Main Authors: Moro, G, Charvet, P, Rosa, R S
• Format: Journal Article
• Language: English
• Published: São Carlos Instituto Internacional de Ecologia 01.11.2012
• Subjects: Animal behavior; Arid environments; Chondrichthyes; Crustaceans; Dasyatidae; Diet; Diptera; Ecosystems; Endemic species; Ephemeroptera; Food; Freshwater; Insects; Nutritional requirements; Potamotrygon; Potamotrygonidae; River basins; River ecology; Rivers; Seasonal variations; Semiarid environments; Brazil, Parnaiba R
• ISSN: 1519-6984; 1678-4375

Potamotrygon signata is an endemic freshwater stingray species in the Parna...ba River basin, Brazil. After its original description, only citations in systematic lists were recorded in the literature and the biology of the species remains unknown, including the feeding habits. The aim of this study is to characterize the overall diet of P. signata based on analysing stomach contents and to provide preliminary information on intraspecific diet variability between sexes and maturity stages. Immature individuals showed a dominance of Diptera (76.20%) while mature individuals showed a similar occurrence of Diptera (46.95%) and Ephemeroptera (47.23%). The observed sexual and ontogenetic differences in diet may be related to distinct nutritional requirements of males and females, and to the variation of morphological aspects of the oral apparatus and dentition of males and females and of immature individuals and adults. The essentially insectivorous diet of the species is possibly adaptively advantageous in the Caatinga semi-arid environment, where the availability of fish as prey may be subject to strong seasonal variation.