Teodoro Vaske Júnior

Feeding habits of the blue shark (Prionace glauca) off the coast of Brazil

Stomachs from 222 blue sharks collected along the Brazilian coast were analyzed - 116 from the northeastern region and 106 from the southern region. A total of 51 prey taxa were identified. The most important prey items in the southern region were Mysticeti whales, teleosteans, the gempylid Ruvettus pretiosus and the nomeid Arioma bondi. Cephalopods were more diverse, with dominance of vertical migrants Histioteuthis spp., Cranchiidae and the epipelagic octopus Ocythoe tuberculata. In the northeastern region, blue sharks consumed mainly teleosteans, including the alepisaurid Alepisaurus ferox and the gempylid Gempylus serpens. Among cephalopods, Histioteuthis spp. and the epipelagic octopus Tremoctopus violaceus were the dominant items. Predation upon schooling prey was occasional, as observed on Arioma bondi. Birds also were consumed in both regions; Puffinus gravis was the fifth most frequent item in the northeastern region. During the reproductive migration cycle, blue sharks likely prey in the thermocline, which is deeper in the northeastern region and closer to the surface in the southern region.

Are deep-sea cephalopods really common preys for oceanic seabirds?

An analysis of published data on oceanic seabirds diets, show the predominance of muscular cephalopods with superficial distribution in the oceanic layers, but also important are the gelatinous and ammoniacal species restrict to layers below 300 m from the surface. In principle, it could be not expected that deep-sea cephalopods are common prey for seabirds like several authors have been concluded. It is proposed in this study that an indirect source, important and easily attainable, have been appeared with the beginning of tuna longline operations. The habit to feed upon viscera of the fishes captured by tuna longliners, that discard the gut contents to the water, may explain the probable equivocal conclusions that deep dwelling cephalopods are natural prey of oceanic seabirds.

Annelida, Hirudinida, Stibarobdella moorei (Oka, 1910): new distribution and host records

Universidade Estadual Paulista (UNESP), Instituto de Biociencias de Botucatu, Departamento de Parasitologia, Distrito de Rubiao Junior s/n, CEP 18618-970, Botucatu, SP, Brazil

Stomach contents and notes on the reproduction of the Onefin Skate Gurgesiella dorsalifera (Chondrichthyes: Rajidae) off Southern Brazil

The Brazilian endemic deep-water onefin skate (Gurgesiella dorsalifera) is a rare small species recently described in the 80s. No biological information is available on this species and its extremely restricted geographic distribution has been used to classify it as a vulnerable species under IUCN red list criteria. Twenty four specimens (115 to 207 mm disc width) were captured off southern Brazilian coast at the region of Cape Santa Marta Grande (State of Santa Catarina) by deep-water otter trawl (430-524 m). The analysis of stomach contents revealed an apparent opportunistic predation on juveniles of Urophycis brasiliensis (IRI = 6944), with an average total length of 21 mm, followed by mysidaceans (IRI = 2938), unidentified teleosts (IRI = 1969), the copepod Bradyidius plinioi (IRI = 393), and decapod crustaceans (IRI = 297). One mature female with 207 mm DW had two egg cases in its uteri.