Seasonal changes in reproductive status of adult male Taricha granulosa were studied. Spermatogenetic activity was found to resume in late spring when the concentration of androgen (testosterone plus dihydrotestosterone) in the plasma is low, less than 5 ng/ml. The concentration of androgen remain low during the summer, until spermatogenesis is nearly complete and spermiogenesis is occurring. Spermiation begins in early autumn coincident to a pronounced increase in plasma androgens (54.7 ± 7.9 ng/ml). A second peak in androgen concentration occurs in the spring as spermiation is completed and breeding activity is most intense. © 1980, All rights reserved.
Specker, J. L., & Moore, F. L. (1980). Annual cycle of plasma androgens and testicular composition in the rough-skinned newt, Taricha granulosa. General and Comparative Endocrinology, 42(3), 297–303. https://doi.org/10.1016/0016-6480(80)90158-6