THE SEMINAL-VESICLES OF THE MALE GRASS GOBY, ZOSTERISESSOR-OPHIOCEPHALUS (TELEOSTEI, GOBIIDAE) - FINE-STRUCTURE AND HISTOCHEMISTRY

The fine structure of the seminal vesicles of Zosterisessor ophiocephalus, the annual changes during the reproductive cycle, and the composition of the secretion are investigated by electron microscopy and by enzyme, polysaccharide, and protein histochemistry. The seminal vesicles are accessory glands of the male reproductive system which produce sialoglycoproteins during the spawning period. They show a significant annual cycle. During the postspawning period they have a regressive phase, followed by a regeneration phase during interspawning and a proliferation phase during prespawning. Possible functions of the seminal vesicle secretion are discussed.