Feeding habits of the toothed flounder Cyclopsetta querna caught in the south-east Gulf of California were studied. Specimens were collected via demersal fish surveys. Results of this study show that C. querna is a predator that focuses on fish inhabiting the bottom and in particular on tonguefish (Symphurus sp.), midshipman fish (Porichthys sp.) and moray eels (Muraenidae). The diet of the toothed flounder did not vary significantly throughout the period of study, and neither size nor sex-related variations in diet composition were observed. Simpson's index indicates a limited trophic niche breadth with a diet dominated by a limited number of taxa. The estimated TROPH value for C. querna is similar to that estimated for other demersal top predators from the studied area; therefore, the toothed flounder can be considered a top carnivore from the demersal community in the Gulf of California.
