Development of spermatogenesis in captive-bred Spix's yellow-toothed cavy (Galea spixii).

TheaimofthisstudywastoevaluatethephasesofsexualdevelopmentandspermatogenesisofSpix'syellow- toothed cavy (Galea spixii) based on analyses of the structural components of the testes. The testes of animals from 0 to 150 days of age were collected by orchiectomy, weighed, and processed for analysis by light microscopy. At 45 days of age, spermatozoa were seen in the tubular lumen. Spermatogenesis was not established in animals from 45 to 150 days of age. The stages of sexual development may be classified into the following phases: from birth to the age of 15 days (immature); 30 days of age (prepubertal); 45-105 days of age (pubertal); and 120 and 150 days of age (postpubertal). This is the first study to address the male reproductive biology of Spix's yellow-toothed cavy. Additional keywords: puberty, rodentia, sexual development, testis, wild animal.