Biological data of the deep-water lizard catshark Schroederichthys saurisqualus (Chondrichthyes: Scyliorhinidae) in southern Brazil

Schroederichthys saurisqualus is a small shark endemic to the southwestern Atlantic, with known distribution on the upper continental slope of southern Brazil, ranging between 122 and 435 m in depth, where it is a trawling bycatch component. In the present study, 124 S. saurisqualus specimens collected between 280 and 500 m in depth from September to October 2002 were analyzed concerning reproductive and feeding aspects. Specimen sizes ranged from 252 to 610 mm total length (TL) for males and 280 to 602 mm TL for females. All males larger than 550 mm TL presented calcified claspers, while seven females (524 to 602 mm TL) presented forming eggs. The data reported herein indicate a first maturity size of about 500 mm TL for both males and females. Stomach content analysis identified the squid Illex argentinus as the most frequent prey, observed in 76.86% of the examined stomachs. The results indicate that S. saurisqualus displays a mate-finding strategy during the reproductive season, when squid predation ocurrs. However, this behavior puts this small catshark population in a vulnerable situation, since intense squid trawling activities are noted during the same period in the same area, exposing the local juvenile S. saurisqualus population to higher fishing pressures.