The diet of the Guiana dolphin Sotalia guianensis in the southwestern Gulf of Venezuela, Zulia State, Venezuela, was investigated through the analysis of stomach contents from 12 dead individuals (11 adults and one juvenile) recovered from incidental captures in artisanal trammel nets and stranding events between 2003 and 2005. A total of 16 prey taxa (15 teleost species and one cephalopod species) were identified from fish otoliths and cephalopod beaks. Numerical frequency (%NF), frequency of occurrence (%FO), and the Relative Importance Index (RII) were calculated for each prey taxon. A total of 327 prey items were recorded in the stomach contents, with teleost fishes constituting the main prey group. The cephalopod Doryteuthis pleii and the nematode Anisakis sp. were each recorded in a single stomach. The most important prey species were the rhomboid mojarra Diapterus rhombeus (Gerreidae, %NF= 42.60; %FO= 54.55; RII= 2323.83) and the acoupa weakfish Cynoscion acoupa (Sciaenidae, %NF= 17.16; %FO= 18.18; RII= 312.0). These results provide the first detailed description of the diet of S. guianensis in the southwestern Gulf of Venezuela and establish a baseline for future studies on its feeding ecology, trophic interactions, and conservation in the region.
