DISTRIBUIÇÃO ESPACIAL E COMPOSIÇÃO DAS POPULAÇÕES DE TUBARÕES DO GÊNERO Etmopterus DO TALUDE CONTINENTAL DO SUL DO BRASIL.
A total of 152 specimens of Etmopterus, were studied. This specimens were caught by bottom-trawl cruises in winter of 2001 and summer of 2002, in the Rio Grande do Sul coast between Chuí (34° 20? S) and Santa Marta Grande Cape (28°30? S), at depths from 100 to 600 m. The species were identified as Etmopterus gracilispinis, E. lucifer, e E. bigelowi, and occurred only at south of 31o S. E. bigelowi occurred on the deep strata from 400 to 599 m, E. gracilispinis occurred from 300 to 599 m, and the both male E. lucifer caught occurred on the depth of 540 m. The hydrographic conditions of temperature and salinity showed no seasonal differences,and the species occurred on bottoms consisting of silte and clay. Most of specimens caught were immature, what is an evidence of segregation by size and implying that theadult of these species occur at depths under 600 m. Sexual maturity appeared in E. bigelowi males of 60 cm of total length and in females starting from 63 cm of totallength, having been collected a gravid female in August. All E. gracilispinis specimens were immature, and one male of E. lucifer with total length of 38 cm was mature. Was find out birth in March for E. bigelowi and for E. gracilispinis, with total length at birth of about 17 and 13 cm, respectively.
Advisor:Carolus Maria Vooren; Marlise de Azevedo Bemvenuti; Rosângela Paula Teixeira Lessa
School:Fundação Universidade Federal do Rio Grande
Source Type:Master's Thesis
Date of Publication:06/17/2005