The Bathyraja spp. skates from the Argentinean continental shelf, with emphasis on the broadnose skate Bathyraja brachyurops.

IBAÑEZ PEDRO; FIGUEROA DANIEL E.; BELLEGGIA, M.

Joao Pessoa

Congreso; Sharks International Conference; 2018

AES, SBELL, SQUALUS

The purpose of this study wasto investigate the diet, the reproduction, the population dynamics and biomasstrends of the broadnose skate Bathyrajabrachyurops from the southwestern Atlantic Ocean, based on a comprehensivedataset obtained from 1999 to 2012. A total of 1.757 skates were caught, measuredto the nearest mm, weigthed, sexed and maturity stage determined. Food habitswere studied based on analysis of stomach contents from a subsample of 344specimens, from which 290 (84.3%) contained food. The diet consisted in fish onthe north and crustaceans in the southern region. We found that the length atwhich 50% of skates are mature (LT50) differed between sexes, regionand periods. The LT50 were estimated to be 707 mm for females, and 683mm for males. The LT50 for males decreased from 697 mm to 673 mmfrom 1999-2006 to 2007-2012 in the northern region, whereas the LT50for females decreased from 750 mm to 688 mm from 1999-2006 to 2007-2012. In thesouthern region, the LT50 for males decreased from 675 mm to 623 mmfrom 1999-2006 to 2007-2012, whereas the LT50 for females decreasedfrom 711 mm to 636 mm from 1999-2006 to 2007-2012. Females with egg capsuleswere found between 70 and 208 m depth. Skates catch data from research vesselswere interpolated and plotted to show the dynamics of this species in theSouthwestern Atlantic. Total biomass estimation of broad nose skate wereanalyzed throughout time series.