Environmental factors trigger the spermatogenesis cycle of the toad Rhinella schneideri (anura: bufonidae)

Abstract

This study investigated the correlation between environmental factors and spermatogenetic activity in Rhinella schneideri males from the Cerrado biome. Over 12 months, we examined the reproductive cycle using biometric, histological, morphometric, and stereological analyses. Morphometric and stereological parameters, along with the Gonadosomatic Index (GSI), varied significantly throughout the year. These variations were related to environmental conditions from the month prior to specimen collection, with a notably negative correlation between peak breeding activity and rainfall. Despite exhibiting a continuous reproductive cycle, R. schneideri males showed seasonal morphological changes in testicular tissue. A delayed response in the spermatogenesis cycle to environmental fluctuations was also observed, suggesting that environmental factors act as biological triggers. Our findings indicate that R. schneideri is well adapted to the challenging environmental conditions of the Cerrado, which are typically unfavorable for most frog species in other biomes.