O presente estudo apresenta novas informações sobre os hábitos alimentares de golfinhos-pintados-do-Atlântico, Stenella frontalis, no Atlântico Sudoeste. Foram analisados nove conteúdos estomacais de S. frontalis acidentalmente capturados em operações de pesca entre 2005 e 2007 pela frota pesqueira do município de Cananéia (25°00'S; 47°55'W), sudeste do Brasil. Foram recuperados dos conteúdos estomacais 1 422 bicos de cefalópodes, 147 otólitos e três camarões. Dos itens analisados, foram reportados um mínimo de oito espécies de peixes pertencentes às famílias Trichiuridae, Carangidae, Sparidae, Merluccidae, Engraulidae, Sciaenidae, Congridae e Scombridae, cinco espécies de cefalópodes pertencentes às famílias Loliginidae, Sepiolidae, Tremoctopodidae e Thysanoteuthidae, e uma espécie de camarão da família Penaeidae. Com base no Índice de Importância Relativa (IRI), o peixe-espada, Trichiurus lepturus, correspondeu à espécie de peixe com maior importância. Entre os cefalópodes, a espécie que apresentou o maior valor de IRI foi Doryteuthis plei. Algumas espécies foram reportadas pela primeira vez como presa de S. frontalis em águas brasileiras: Xiphopenaeus kroyeri, Tremoctopus violaceus, Semirossia tenera, Merluccius hubbsi, Pagrus pagrus e Paralonchurus brasiliensis. S. frontalis apresentou hábitos alimentares teutófagos e ictiófagos, com aparente predomínio do primeiro, e predou principalmente sobre itens pelágicos e demersais.

This study presents new information on the feeding habits of the Atlantic spotted dolphins, Stenella frontalis, in the Western South Atlantic. Nine stomach contents of S. frontalis incidentally caught in fishing operations conducted by the gillnet fleet based on main harbour of Cananéia (25°00'S; 47°55'W), southeastern Brazil, were analyzed. These specimens were captured between 2005 and 2007. A total of 1 422 cephalopod beaks, 147 otoliths and three crustaceans were recovered from the stomach contents. The dolphins assessed preyed on at least eight different fish species of the families Trichiuridae, Carangidae, Sparidae, Merluccidae, Engraulidae, Sciaenidae, Congridae and Scombridae, five cephalopod species of the families Loliginidae, Sepiolidae, Tremoctopodidae and Thysanoteuthidae, and one shrimp species of the Penaeidae family. Based on the analysis of the Index of Relative Importance (IRI), the Atlantic cutlassfish, Trichiurus lepturus, was the most important fish species represented. Of the cephalopods, the squid Doryteuthis plei was by far the most representative species. Several items were reported for the first time as prey of the S. frontalis: Xiphopenaeus kroyeri, Tremoctopus violaceus, Semirossia tenera, Merluccius hubbsi, Pagrus pagrus and Paralonchurus brasiliensis. S. frontalis presented teuthophagous and ichthyofagous feeding habits, with apparent predominance of the first, and preyed mainly on pelagic and demersal items.

The aim of the present study was to provide a preliminary description of habitat use by Guiana dolphins, Sotalia guianensis (Van Bénéden, 1864) in the Paranaguá Estuarine Complex (PEC), state of Paraná, Brazil. Approximately 124 km² were surveyed by small boat from April 2006 to July 2008 in the following subsets of the PEC: Canal do Superagui (~28 km²); Pinheiros Bay (~34 km²); part of Laranjeiras Bay, which included the Guaraqueçaba sub-estuary (~38 km²); and part of the Mixture Section of the PEC (~24 km²). Our efforts were unevenly distributed in the study area. During 55 survey days covering seven distinct seasons, we spent 165 hours observing 323 groups of S. guianensis. Group size varied from two individuals to aggregations as large as approximately 100 dolphins. A total of 49,921 photographs were analyzed; 15,038 (30%) were considered useful for identification purposes. A total of 182 individuals were catalogued, from which 122 (67%) were cataloged in the last three seasons, when the surveyed area was expanded. The number of individual sightings in distinct days varied from one to 16. A total of 94 individuals (51.6%) were re-sighted at least once. From the 37 individuals cataloged in the first season, 18 (48.6%) were re-sighted in the last season. Eleven individuals with 5+ sightings were always observed in the same subset of the estuary, including an individual with 13 sightings. Sixteen individuals with three to 16 sightings were observed in three of the four estuary subsets surveyed. An individual cataloged in May 2002 in a pilot study was re-sighted up to August 2006. Our preliminary results correspond to the first evidence of site fidelity for several monitored individuals; it also revealed, for the first time, the flexibility of movements throughout the entire estuarine complex by several other individuals