Notes on the reproductive biology of the Brazilian electric ray Narcine brasiliensis (Elasmobranchii: Narcinidae).

This study provides information on the reproductive biology of Narcine brasiliensis based on 105 individuals (72 females and 33 males) sampled in São Paulo State, Brazil. The total length at maturity for females was 318·9 mm and for males was 279·8 mm; pregnant females were observed only during summer and autumn. The peak of the gonado-somatic index for females and condition factor for males in the spring suggest a preparation for pregnancy and a mating period during this season. The capture of immature individuals indicates a need for management of the species in this region.

Feeding habits of the shortnose guitarfish, Zapteryx brevirostris (Müller and Henle, 1841) (Elasmobranchii, Rhinobatidae) in southeastern Brazil.

The feeding habits of the shortnose guitarfish, Zapteryx brevirostris, were studied based on 382 specimens from the northern São Paulo coast, southeast Brazil. The diet showed a predominance of crustaceans (carideans and amphipods), polychaete annelids, and occasionally small fish, sipunculids, and cephalopods. The diets of males and females were similar; however, differences in the proportion of prey items were found among juveniles, subadults, and adults. Differences in the ingestion of prey items were found during the year, probably influenced by oceanographic parameters, although in general, the species feeds mostly on crustaceans and polychaetes.

Occurrences of whale shark (Rhincodon typus Smith, 1828) in the Saint Peter and Saint Paul archipelago, Brazil.

The Saint Peter and Saint Paul Archipelago in the central tropical Atlantic, is an important ground of whale sharks that are commonly sighted throughout the year close to the fishing boats in the adjacencies of the islands. In sightings reported between February 2000 and November 2005, the lengths of the individuals ranged between 1.8 to 14.0 m. The causes of these concentrations in the archipelago are still unclear, once there are no upwellings and plankton concentrations for feeding, and no reproductive activities were reported. Nevertheless, they could be associated to the spawning period of the abundant flying fishes, mainly in the first semester, when sightings were more frequent.

Occurrences of whale shark (Rhincodon typus Smith, 1828) in the Saint Peter and Saint Paul archipelago, Brazil / Ocorrências de tubarão-baleia (Rhincodon typus Smith, 1828) no arquipélago de São Pedro e São Paulo, Brasil

The Saint Peter and Saint Paul Archipelago in the central tropical Atlantic, is an important ground of whale sharks that are commonly sighted throughout the year close to the fishing boats in the adjacencies of the islands. In sightings reported between February 2000 and November 2005, the lengths of the individuals ranged between 1.8 to 14.0 m. The causes of these concentrations in the archipelago are still unclear, once there are no upwellings and plankton concentrations for feeding, and no reproductive activities were reported. Nevertheless, they could be associated to the spawning period of the abundant flying fishes, mainly in the first semester, when sightings were more frequent.

O Arquipélago de São Pedro e São Paulo situado na área central tropical do Atlântico, é um importante local de concentração de tubarões-baleia, que são vistos ao longo de todo ano, próximos às embarcações de pesca nas adjacências das ilhas. Em avistagens registradas entre fevereiro de 2000 e novembro de 2005, os comprimentos dos indivíduos variaram entre 1,8 e 14 m. As causas destas concentrações no arquipélago ainda não são claras, uma vez que não há há ressurgências e grandes concentrações de plâncton no arquipélago, e também não foram observadas atividades reprodutivas. No entanto, podem estar associadas ao período de desova dos peixes-voadores, marcadamente no primeiro semestre, quando as aparições são mais freqüentes.