New contribution to the reproductive features of bluemouth Helicolenus dactylopterus dactylopterus from the northeast Atlantic (Azores Archipelago)

Abstract

This work describes and identifies the macroscopic and corresponding microscopic changes of the gonads of an important commercial fish species, Helicolenus dactylopterus dactylopterus, from Azores Archipelago. The new contribution relates the macroscopic scale with the histological stages. The annual changes in the gonad, together with the analysis of the monthly gonadosomatic indices, and complementary observations with scanning electron microscopy, allow us to conclude that the females are internally inseminated between July and November and spawn between January and March. There is a separation between female and male reproductive cycles. The overall sex-ratio observed was 1:1, but seasonal and length related differences were observed. This suggests differences and changes in availability, probably related to the annual reproductive cycle and changes in feeding behaviour.