Gonadal structure and gametogenesis of Aspitrigla obscura (Pisces, Triglidae)

The structure of the gonads and the different stages of development of the germ cells of Aspitrigla obscurra are described for both sexes. The saccula r cystovarian ovaries contain the ovigerous lamellae, which spreads from th e periphery to the centre of the gonad, where the lumen is located. Develop ment is of the synchronic group type. Besides the corpora lutea and atretic bodies, eight stages of development are described, based on the histologic al and ultrastructural characteristics of the oocytes. The testes are lobul ar and of the 'unrestricted spermatogonial' type. The male germ cells were divided into eight stages that were analysed basically by means of transmis sion electron microscopy. The gonadal structure shows that A. obscura lays on multiple occasions over a relatively prolonged period of time. The large drops of oil of the mature oocyte indicate that spawning is pelagic. The m orphological characteristics of the spermatozoon indicate external fertilis ation.