Studies of the male reproductive cycle in the toad, Buto bankorensis were conducted on spermatogenetic activity, direct measurements of plasma androgen, and changes in the weights of testes, liver and fatbody. A total of 110 male Buto bankorensis were collected from March 1990 to March 1991 in central Taiwan. Histological evidence indicates that the spermatogenetic cycle of this toad is of a potentially continuous type. Although cell nests of all spermatogenic types were present every month of the year, the greatest intensity of spermatogenetic activity (sperm bundles and mature sperm) occurred during August to November. Plasma androgen levels exhibited a significant difference in level between September and June (mean values = 93 nglml and 2.5 nglml, respectively). The weights of fat bodies peaked during the months of May, June and July, coincident with the beginning of breeding, and they had regressed in December by the end of the period of intense spermatogenetic activity. Testicular weight increased slowly in August and peaked in September. Combined data from spermatogenetic activity, plasma androgen, and changes in weights of testes, fat bodies, and livers showed that B. bankorensis is a potentially continuous breeder. However, its annual reproductive cycle could be clearly divided into these periods: 1) breeding period (August to November); 2) postbreeding period (December to February); 3) reproductive energy preservation period (March to May); and 4) torpid period (June to July).
Reproduction, Bufonidae, Spermatogenesis, Androgen, Taiwan
