REPRODUCTIVE-BIOLOGY OF ATLANTIC HALIBUT (HIPPOGLOSSUS-HIPPOGLOSSUS) IN CANADIAN WATERS

Through examination of commercial fishery samples, surveys conducted f rom research vessels, and fishery observer programs, the reproductive biology of Atlantic halibut (Hippoglossus hippoglossus) in the Canadia n North Atlantic is described. Using data derived from conventional te chniques including histology and visual assessment of maturity, and a more novel approach using image analyses equipment, halibut were found to be group-synchronous spawners whose spawning activity peaks in the November-December period, considerably earlier than was previously th ought. Our analyses also allowed us to comment on the life history of Atlantic halibut in Canadian waters. The comparative absence of spawne rs in the continental shelf/slope areas may mean that halibut spawn in comparatively deep water, consistent with the habits of the Pacific m ember of the genus, H. stenolepis. Immature fish typically occurred on the southwestern Scotian Shelf but rarely off Newfoundland, supportin g the view that the former area is an important rearing area for immat ure halibut.