Reproductive Cycles of Redfishes ( Sebastes ) in Southern Newfoundland Waters

Abstract

Rapid field identification of Sebastes mentel/a, S. fasciatus and small S. marinus is difficult. Thus, redfish species are not distinguished for commercial statistics and the beaked redfishes usually not differentiated in biological sampling, the result being a lack of biological information by species. Knowledge of the ovoviviparous reproductive cycle of Sebastes sp. is important for species differentiation and stock discrimination. Investigations of sexual maturity and spawning in redfishes of southern Newfoundland waters (NAFO Division 3P) were carried out on the basis of 11,520sex and maturity observations collected from 1957 to 1969. Stages of sexual maturity are described. Monthly changes of maturity condition and maturity factor indicated that beaked redfishes (S. fasciatus) spawned mainly in May/June and S. marinus probably spawned earlier. Materials and Method Fig. 1. Areas where redfish samples were collected off southern Newfoundland in 1957-69. During 1957-69, 11,520 redfish specimens were collected from the otter-trawl catches of research vessels during daytime in southern Newfoundland waters (Fig. 1) at bottom depths to 578 m, in which 82% of the specimens were from 200-299 m. Sampling sites were 56" st. Pierre Bank 57"' 58" 59"-, \ \ \ \ \ \ \ \~ \'? Banquereau \ \ \ \ \ \ \-, " 46" / I 48" I \ 47" For this paper, monthly variation in length frequencies , sex ratios, maturity condition and maturity factors of golden redfish (S. marinus) and beaked red-fishes (S. fasciatus and S. mentella combined) were investigated from data collected in southern New-foundland waters (Div. 3P). The study also involved size at maturity and variation in distribution of the species with depth. The reproduction cycle and its role in species and/or stock discrimination of redfishes are discussed.