Study on reproductive biology of Champsocephalus gunnari, Chaenocephalus aceratus and Pseudochaenichthys georgianus from South Georgias and Shag Rocks

MILITELLI, M I; MACCHI, GJ; RODRIGUES, K

Hobart

Workshop; CCAMLR Thirty-second Meeting of the Scientific Committee; 2013

The reproductive biology of C.gunnari, C. aceratus and P.georgianus was studied in South Georgia and Shag Rocks. The macroscopic information analyzed indicated the presence of C. gunnari, C. aceratus and P. georgianus totally mature females (with hydrated oocytes) this not only confirms the spawning of C.gunnari in South Georgia and Shag Rocks, but it also suggests spawning of P.georgianus and C.aceratus. C. gunnari batch fecundity showed a potential fit to size and a lineal fit to weight and ranged from 2,500 (27 cm TL) to 21,300 (54 cm TL) hydrated oocytes. Batch fecundity values for P.georgianus and C.aceratus showed a lineal fit to size and weight, they ranged between 6,600 (47 cm TL) and 8,400 (52 cm TL) hydrated oocytes and 7,800 (55 cm TL) and 14,400 (63 cm TL) hydrated oocytes respectively. Mean relative fecundity values were 21 oocytes/g for C.gunnari and 7 oocytes/g for C.aceratus and P.georgianus. In the case of C.gunnari and P.georgianus it was observed that relative fecundity decreased with increasing length and weight of the females. Diameter and dry weight of C.gunnari hydrated oocytes showed a positive relationship with female size.