Pigments on the testes of five amphibians endemic to Cuba (Eleutherodactylus turquinensis, E. cuneatus, E. glamyrus, Bufo longinasus longinasus y B. longinasus cajalbanensis)

Abstract

Ectothermic vertebrates may have a pigment of unknown function, although in some cases melanomacrophage centers with apparent phagocytic function have been described; however, it is not common to find pigmented gonads in Anuran amphibians. The main objective of this paper is to report and analyze the presence of pigment in the testes of frogs (three species) and toads (one species), all of which are endemic to Cuba:  Eleutherodactylus turquinensis, E. cuneatus, E. glamyrus, and Bufo longinasus (subspecies B. longinasus longinasus and B. longinasus cajalbanensis). The specimens were collected in western and eastern areas of the Island of Cuba and were anesthetized with ether once taken to the laboratory. Gonads were extracted and processed for light microscopy and, in the case of B. longinasus, also for transmission electron microscopy. The results show a morphology that is similar to that in other anuran testes; there was a cystic organization of sex cells in the seminiferous tubules and all animals were in total spermatogenesis. The testes of all studied species showed a dark and abundant pigmentation in the tunica albuginea and in the interstitial tissue. Many melanosomes were observed. In this paper, we analyze that the cause of strong testicular pigmentation may be a response to pollution and it is proposed that pigments are produced by another cell type similar to melanomacrophages, but not by melanocytes.