Reproductive biology of the cockfish, Callorhinchus callorynchus (Chondrichthyes: Callorhinchidae), in coastal waters of the northern Argentinean Sea

CHIERICHETTI MELISA; SCENNA LORENA; DI GIACOMO EDGARDO; ONDARZA PAOLA MARIANA; FIGUEROA DANIEL; MIGLIORANZA KARINA SILVIA BEATRIZ

NEOTROPICAL ICHTHYOLOGY

SOC BRASILEIRA ICTIOLOGIA

Lugar: Porto Alegre; Año: 2017

1679-6225

The cockfish, Callorhinchus callorynchus, is a widely distributed holocephalan in the south-western Atlantic and animportant resource for Argentinean fisheries. The reproductive characteristics of this species were studied in northernArgentinean coastal waters, where specimens arrive seasonally (winter-spring). Sexual dimorphism in maximum precaudallength (PCL) and total body mass (TM) was found, being females (PCL=630 mm; TM=3330 g; n=167) larger and heavierthan males (PCL=482 mm; TM=1630 g; n=19). Maturity size for females was 466.22 mm PCL, representing 74% PCL ofthe largest female sampled. The mean number of ovarian follicles was 8.37 (± 4.84). The highest values of ovarian folliclesdiameter, gonadosomatic and oviducalsomatic indices were found in spring. A high proportion of mature females (44%)had atretic ovarian follicles, suggesting that they were in the resting stage of their reproductive cycle. The low numberof mature males recorded and the absence of mature females with spermatophore masses or egg cases indicate that thestudy area would not be a reproductive zone. The seasonal presence of C. callorynchus in this region could be related totrophic movements. These results, obtained in an area with high fishing pressure on chondrichthyans, will be useful forimplementing conservation and management measures.