The diet of cubomedusae Tamoya haplonema Müller, 1859 (Carybdeidae) and Chiropsalmus quadrumanus (Müller, 1859) (Chirodropidae) was examined in specimens collected on the Southern Brazilian coast (25º20' - 25º55'S; 48º10' - 48º35'W), between December 1998 and December 2004. This is the first study to analyze this biological aspect in cubomedusae from the South Atlantic. The gastrovascular cavities of most (55%; n = 29) specimens of T. haplonema were empty while the remainder had teleosteans parts such as scales, vertebrae and otoliths. In C. quadrumanus (n = 726), the most important items were the pelagic sergestid shrimp Peisos petrunkevitchi Burkenroad, 1945 and Brachyura larvae, mainly megalops. Small crabs, isopods, fish, fish eggs and nematodes were less common. A dietary shift was clearly observed during C. quadrumanus growth. Smaller individuals consumed a greater variety of prey, mostly Brachyura larvae, and they also had higher frequencies of empty stomachs. As their size increased, megalopas decreased and P. petrunkevitchi became the most important item in their diet.
Chiropsalmus quadrumanus; Feeding biology; Jellyfish; Medusae; Ontogenetic dietary shift; Tamoya haplonema