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Previous studies have revealed variations in the urogenital system morphology of amphibians. Recently, the urogenital system of salamanders was reviewed and terminology was synonymized across taxa. Discrepancies exist in the terminology describing the urogenital system of anurans, which prompted our group to develop a complete, detailed description of the urogenital system in an anuran species and provide nomenclature that is synonymous with those of other amphibian taxa. In Rana catesbeiana, sperm mature within spermatocysts of the seminiferous tubule epithelia and are transported to a series of intratesticular ducts that exit the testes and merge to form vasa efferentia. Vasa efferentia converge into single longitudinal ducts (Bidder's ducts) on the lateral aspects of the kidneys. Branches from the longitudinal ducts merge with genital kidney renal tubules through renal corpuscles. The nephrons travel caudally and empty into the Wöffian ducts. Similar to salamanders, the caudal portion of the kidneys (termed the pelvic kidneys in salamanders) only possesses nephrons involved in urine formation, not sperm transport. Data from the present study provide a detailed description and synonymous nomenclature that can be used to make future comparative analyses between taxa more efficient. [ABSTRACT FROM AUTHOR]

Female reproductive cycle and clutch size are important life history traits in lizards that can be influenced by biotic and/or abiotic factors. Here, the ovarian cycle and clutch size of a high-elevation population (1500–1600m) of Aspidoscelis costata costatain Central Mexico are described. Females were collected monthly between 2005 and 2007, and their reproductive condition was evaluated based on appearance and size of ovarian follicles and presence/absence of oviductal eggs. The reproductive cycle was markedly seasonal with asynchrony in reproductive condition among females. Vitellogenic and gravid females were recorded from April (end of the dry season) through July (middle of the rainy season). Although this population inhabits a semi-humid warm climate, the timing of female reproduction in A. costata costatais similar to the cycle of temperate-zone species of Aspidoscelis. Females produced a single clutch annually with an average clutch size of 7.7±0.44 eggs (median 8 eggs, range 4–14), which is the largest reported to date within the genus Aspidoscelis.

Abstract: Novel ventrally positioned extra-cloacal glands were discovered through examination of cloacal histology of female thamnophiine snakes. The glands discovered, termed ventral urodeal glands, are paired and empty into the caudal extremity of the urodeum, lateral to the opening of the urodeal sphincter, through primary ducts that resemble folds of the urodeal wall. In concordance with historical literature, these glands are the first cloacal glands described in snakes that definitively empty into the urodeum from a ventral position. Ventral urodeal glands are complex, with multiple branching ducts that empty the terminal alveolar glands. The epithelial linings of the branching duct networks are stratified (primary and secondary ducts), pseudostratified (tertiary ducts), or simple (quaternary ducts and terminal alveoli). The epithelia of the terminal alveoli stain weakly with hematoxylin, and an eosinophilic secretory material is common in the lumina of alveoli. The secretion produced in the alveoli stains positive with the periodic acid-Schiff's procedure, negative with brilliant blue, and positive with fast green, indicating that the majority of the secretion is composed of a neutral carbohydrate moiety with a minor protein component. Ventral urodeal glands were observed in all taxa of Nerodiaexamined, except N. cyclopion, and were not observed in any other taxa of Thamnophiini. Through optimization to Thamnophiini topologies, ventral urodeal glands either evolved once on the branch leading to Nerodiaand were subsequently lost on the branch leading to N. cyclopion, or they evolved independently on the branches leading to N. floridanaand all other species of Nerodia. Like many of the cloacal glands in squamates, the function of ventral urodeal glands is unknown, and further investigation is needed to elucidate the function of the secretions of these glands.