Zoological Studies

Vol. 41 No. 4, 2002

Gonadal Structure and Gametogenesis of Trigla lyra (Pisces: Triglidae)

Marta Muņoz*, Maria Sābat, Sandra Mallol and Margarida Casadevall

Biologia Animal, Departament Cičncies Ambientals, Universitat de Girona, Campus de Montilivi, Girona 17071, Spain

Marta Muņoz, Maria Sābat, Sandra Mallol and Margarida Casadevall (2002) The gonadal structure and development stages of germ cells of Trigla lyra are described for both sexes. The ovigerous lamellae of the saccular cystovarian ovaries spread from the periphery to the center of the gonad where the lumen is located. In addition to the postovulatory follicles and atretic oocytes, seven stages of development are described based on the histological and ultrastructural characteristics of the oocytes. Gonadal development is of the “synchronous group” type. This kind of development and the presence of postovulatory follicles in ovaries which still contain developing vitellogenic oocytes suggest that T. lyra spawns on multiple occasions over a relatively prolonged period of time. Drops of oil in the mature oocyte indicate that spawning is pelagic. The testes are lobular and of the “unrestricted spermatogonial” type. Male germ cells are divided into 8 stages that were principally analyzed by means of transmission electron microscopy. The morphological characteristics of the spermatozoon, as a short head and a barely differentiated middle piece with few mitochondria, indicate external fertilization.

Key words: Reproduction, Gametogenesis, Morphology, Ultrastructure, Triglidae.

*Correspondence: Tel: 972-418498. Fax: 972-418150. E-mail: marta. munyoz@udg.es