Sexual Kidneys in a Plethodontid Salamander

• Published in: Journal of herpetology 2017-06, Vol.51 (2), p.202-208
• Main Authors: Alvino, Sam, Siegel, Dustin S
• Format: Article
• Language: English
• Subjects: RESEARCH ARTICLE
• ISSN: 0022-1511; 1937-2418
• DOI: 10.1670/16-054

Previous studies observed the synthesis of an abundant glycoprotein secretion in the collecting duct tubules of ambystomatid and salamandrid salamanders. The synthesis and release of this secretion occurred during times of mating activity; therefore, researchers concluded that collecting ducts of the pelvic kidneys functioned as secondary sexual structures. The purpose of this study was to determine if any male plethodontids possess kidneys with similar secondary sexual function. We captured male and female Eurycea longicauda longicauda (Common Name) from every month possible and removed their urogenital organs, along with known male secondary sexual glands, for histological examination. The heights of collecting duct and known secondary sexual gland epithelia were measured every month as a proxy for secretory activity. We compared known secondary sexual gland seasonal secretory activity with that of the seasonal secretory activity of the collecting ducts. We then qualitatively compared these data with the seasonal spermatogenic cycle of the testes, seasonal sperm transport through male genital ducts, and seasonal sperm transfer from males to females. Known secondary sexual structures and pelvic kidney collecting ducts increase epithelial height directly prior to and during autumn months, concordant with the later stages of sperm development, transport of sperm through the genital ducts, and transfer of sperm from males to females; i.e., the mating season.