Sexual cycle and seasonal expression of testosterone (T) in the testes of Sclerophrys mauritanica (Schlegel, 1841)

Abstract Sclerophrys mauritanica is an anuran amphibian found in the wetlands of Beni-belaid, Jijel, Algeria. The animals are constrained by wet (from September until May) and dry (from June until August) seasons, however, the sexual cycle of males is continuous (all germ cells categories are present throughout the year). The aim of this study was to follow the changes in the reproductive organs of male toads during the annual breeding cycle using light microscopy. Our study was conducted over the period 2003 to 2005. The surfaces of testicular sections, interstitial tissue and Leydig cells, as well as the number of total seminiferous tubules with spermatozoa in bundles, were analysed. All showed monthly variations throughout the annual breeding cycle. For each year, the surface of testis sections and the number of spermatozoa in bundles fluctuate in the same way throughout the year, with a strong increase during the dry season (maximum in August) and a slow decrease until January. The surface of interstitial tissue remained stable, with the exception of a strong peak in August. Additionally, the surface of Leydig cells showed a substantial peak in May before the dry period. Finally, testosterone was observed every month of the year.