Seasonal Changes in the Structures of the Testes of Greenling, Agrammus agrammus (Temminck et Schlegel)

Seasonal Changes in the Structures of the Testes of Greenling, Agrammus agrammus (Temminck et Schlegel)

Seasonal changes in the structures of the testes of greenling. Agrammus agrammus, was histologically investigated. The materials were monthly collected at the intertidal zone of Tongbaeksom, Pusan, Korea, from July 1981 to August 1984. Sexuality of the species was dioecious. The testis consisting of a pair of lobular structures in the right and left was united in the posterior seminal vesicle. Cortex of the testis was composep of several testicular lobules and medulla was composed of many sperm ducts connected with the lobules. The course of maturation in the present species proceeded synchronously in all cells within a cyst, but it was different more or less from lobule to lobule. Mature spenna- tozoa were accumulated in the lumen of the lobules without any regularity in arrangement. A small number of spennatogonia remained as residual spermato_ gonium in the mature and spent testes. The early development stage showed active spermatogenesis but poor development of interstitial cells. Maximal development of apparently active interstitial cells occurred about the mature and ripe stage during the period from September to December but secretory activity had not been observed clearly in them. It is also su 잃 ested that in the early phases of testicular growth, interstitial ∞ lis probably does not particularly medidate pituitary stimulation of spermatogenesis. The intralobular cyst cells changed clearly along with their sexual maturation. They were thin, elliptical or triangular shape, their nucleus and cytoplasm increased in size during the mature and ripe stage during the period from September to December. while they decreased markedly in size and showed strong affinity to haematoxylin after breeding. Secretory activity of these celis had not been observed clearly in them also. Environmental factors seemed to stimulate testicular growth and maturity as judged from the more advanced sexual stages of the testes. The maturation of the testis was supposed to be induced by shorter photoperiod and lower water temperature, and to reach the spent period.