Annual reproductive cycle of Helicolenus dactylopterus dactylopterus (Teleostei: Scorpaeniformes) with special reference to the ovaries sperm storage

Abstract

In this paper the macroscopic and microscopic morphology of the gonads of Helicolenus dactylopterus dactylopterus (Pisces: Teleostei) were analysed as well as its seasonal histological changes. The testicles are of the lobular type. The cystovarian ovaries have a central rachis from which the ovigerous lamellae are radially suspended. The gonoducts remain independent until they join together at the urogenital papilla which, in males, can be projected towards the exterior serving as a copulating organ. Sperm production is important from July to February. In contrast, the females only have mature and vitellogenic oocytes in winter, from December to February. In the west Mediterranean spawning takes place during the months of January and February. The ovaries contain clusters of spermatozoa for some ten months, from May onwards. By means of an optical microscope a specialized structure is detected, situated at the base of the interlamellar space, where male sexual cells are stored for a long period of time. Nevertheless, for several months many individual spermatozoa are also detected in the interlamellar areas, floating in the ovarian fluid secreted by the epithelium of the ovarian wall. It is still unknown whether the species under study is oviparous or viviparous, as until now, no intraovarian embryos have been detected in any of the specimens analysed.