Morphology and biometry of the reproductive organs of adult males of Trachemys scripta elegans reared in São Paulo state, Brazil

Abstract

Trachemys scripta elegans is an American underwater chelonian illegally marketed in Brazilian pet shops. When abandoned in nature, it compromises native species, threatening local biodiversity. However, little is known about the body development and structure of its reproductive tract. The objective of the present study was to investigate the morphology and biometry of testis, epididymis and penis, as well as the biometry of the body and secondary sexual characters in this species. Twenty-seven adult males were used aiming to contribute to preservation actions in captivity, population control, and scientific research, as well as to interspecific comparisons. Sex identification by the third claw length was effective, and the specimens presented harmonious and positive body development between mass, carapace, plastron, and height, with unimodal tendency and higher frequency of maximum carapace length at 15cm. The testes and epididymides presented biometric similarity between the antimeres and anatomical and histological structure similar to that of other species of chelonians and mammals, except for the type of epithelium. The findings suggest that there is conserved morphology between slider turtles and homology in relation to mammals. Histological similarity to the reproductive organs of other amniotes, including humans, may give rise to scientific and comparative studies, essential for the establishment of conservation strategies in reptiles.

Serum biochemistry of Trachemys scripta elegans and Trachemys dorbignyi (Testudines: Emydidae) bred in captivity in the Northeastern semiarid region of Brazil

“…In T. s. elegans we observed a unimodal distribution of CL values. This distribution agrees with the results of the studies performed by [ 17 , 18 ]. The mean PL values (19.5±2.3 cm) indicated that all the specimens were sexually mature.…”

Determination of sexual maturity of Indonesian box turtle (Cuora amboinensis couro) based on straight carapace length

“…Meanwhile, the testes of Trachemys scripta elegans turtle were oval in shape, bright yellow in color, and were located cranially to the epididymides and caudally to the kidneys (Gradela et al, 2019).…”

“…In the sixth stage, seminiferous tubules were further expanded, and interstitial connective tissue was only observed in the small spaces among the tubules (Otsuka et al, 2012). The seminiferous of Trachemys scripta elegans turtle comprised of Sertoli and spermatogenic cells, while Leydig cells in the interstitial tissue surrounding the seminiferous tubules (Gradela et al, 2019).…”

Morphological changes associated with Nile crocodile (Crocodylus niloticus) phallic glans inflation

“…Glans anatomy has been generally described for mammals, where it is typically an inflatable, cap‐shaped expansion of the corpus spongiosum found at the distal end of the penis (Jubilato et al, 2019; Weiss et al, 2012), but it is more poorly understood for other amniote taxa. Studies of the male turtle reproductive anatomy have, until recently, focused on the gross morphologies of noncopulatory glans, not characterizing glans inflation, internal structures, or histological details (Fernandes Araujo Chaves, Viana, Chaves, Miglino, & de Sousa, 2020; Gradela et al, 2019; Larkins & Cohn, 2015; Zug, 1966). Additional comparative studies are required to better define the anatomy and function of glans tissues across amniotes.…”