Estimation of Sexual Maturity Based on Morphometrics of Genital Organs in Male Northern Fur Seals, Callorhinus ursinus

摘要: It's not always possible to obtain samples from dead male pinnipeds that are fresh enough determine the histological characteristics of spermatogenesis and their stage sexual maturity. We propose morphometrics genital organs northern fur seals, Callorhinus ursinus, can be used as a new indicator analyzed data collected records seals around Hokkaido during 2011–2017 examine in spermatogenesis. First, we investigated ontogenetic seasonal variation three organs: testes, epididymides, bacula. Second, classified stages into groups (Stage A–C) using non-linear discriminant analysis, based on determined by observation seminiferous tubules. Testicular size, testicular mass, epididymal mass showed associated with From our could estimated high accuracy predicting And measurement baculum was suggested an conclude this simple estimation may maturity individual growth patterns.