Reproductive biology of the cockfish Callorhinchus callorynchus (Holocephali: Callorhinchidae), in a coastal area of Argentina.

CHIERICHETTI M.; SCENNA L.; FIGUEROA D.; ONDARZA P.M.; MIGLIORANZA K.S.B.; DI GIÁCOMO E.

Tennessee

Congreso; 2014 Joint Meeting of Ichthyologists and Herpetologists; 2014

Kansas State University

The knowledge of reproductive parameters is needed to assess the status of the populations and to develop effective fisheries management plans. The cockfish, Callorhinchus callorynchus, is an oviparous species of chondrichthyans widely distributed in the Southwest Atlantic (23°-55° S). This species has come under increased fishing pressure on the Argentinean Continental Shelf (34º-55ºS), being an important resource for artisanal, commercial and recreational fisheries. However, the life-history characteristics of C. callorynchus have been only studied in the northern Patagonia (41º-42º S, 64-65ºW). Therefore, we investigated the reproductive biology of this species in coastal area of Argentinean Shelf (36º-37ºS) that supports a high fishing pressure on chondrichthyans. A total of 6 males (385-455 mm precaudal length, PCL) and 143 females (390-630 mm PCL) were collected from small-scale artisanal fishermen catch at depths lower than 50 m, during winter-spring from 2011 to 2013. Males had secondary sexual structures (frontal tenaculum and prepelvic claspers), which would be utilized during mating. The smallest mature female measured 410 mm PCL, whereas the largest immature one was 490 mm PCL. The length at 50% maturity in females was 465 mm, which corresponded to 74% PCL of the largest female sampled. There was not seasonal variation in average number of mature oocytes. Although the highest values of gonadosomatic and liver indices were recorded in October and November (spring), females with eggs cases in their uterus were not found in the study area, suggesting that it would be not a spawning zone for the species.