Abstract1_12 (Hasumi)

Hasumi, M.: Times required for ovulation, egg sac formation, and ventral gland secretion in the salamander Hynobius nigrescens. Herpetologica (USA, International) 52(4): 605-611, December 1996. Stable URL

Abstract: I examined the times required for ovulation, the subsequent formation of egg sacs, and epithelial secretion of ventral glands in gravid females of Hynobius nigrescens that were in a preovulatory condition just before entering a breeding pond. In water at 8 C, ovulation was induced 14-18 h after a single injection of 600 IU human chorionic gonadotropin. By 32 h, almost all ripe ova (i.e., a full clutch) passed through the oviducts and into the ovisacs. The formation of egg sacs was completed in the ovisacs 50 h after the injection, after which each egg sac shifted to the distal part of the ovisac, a structure unknown in other families. I termed this part "dilatable ovisac." The epithelial cells of ventral glands discharged secretions into lumina between 18 h and 32 h after the injection.