Seasonal gonadal changes in adult male lizards of Liolaemus cuyanus (Iguania: Liolaemidae) from the Monte desert, Argentina

BARAUNA, ANDREA ANABELLA; QUIROGA, LORENA BEATRIZ; MONCLÚS, MARÍA ÁNGELES; SANABRIA, EDUARDO ALFREDO; FORNÉS, MIGUEL WALTER

Theriogenology Wild

Elsevier

Año: 2023 vol. 2

2773-093X

Male reproductive cycles in lizards can be continuous or seasonal depending on the environmental conditionsand female availability. The aim of this study is to investigate whether adult males of the psammophilus lizardLiolaemus cuyanus present seasonal changes of reproductive traits throughout the reproductive cycle. In order tocarry out this task, sampling of specimens (N = 27) was carried out monthly from October to March in Valle deMatagusanos, Ullúm, San Juan, Argentina (31°06′46.08′’ S, 68°38′03.84′’ W; altitude: 945 m), a semi-arid zone.The animals captured in different months were grouped based on reproductive criteria according to three re-levant periods: pre-reproductive (PrR), reproductive (R) and post-reproductive (PsR). In order to identify andcharacterize these periods, several male reproductive traits were obtained, like morphometric parameters (bodymass, snout-vent length, testes and abdominal fat body mass), tubular surface and estimation of the interstitialtissue coverage, combined with histological and cell seminiferous tubule observations (germ cells types, histo-logical and ultrastructural details) and presence of sperm in the cauda epididymis. During the PrR period, whichoccurred during spring, well-developed testes with free tubular sperm cells were present, but these were lessfrequent than during the R period. On the other hand, luminal sperm cells were evident at the seminiferoustubules from the beginning of the R period, in conjunction with the maximum testes mass and seminiferoustubular surfaces. This was also coincident with a higher abundance of sperm cells in the cauda epididymallumen. At the end of this period, the initial regression of the seminiferous epithelium was corroborated byorganelle regression which was observed in the ultrastructure of spermatogenic cells. At the beginning of the PsRperiod, before autumn, a marked decrease in male reproductive traits above described was detected. Instead, anincrease in abdominal fat body mass could be observed indicating the onset of the lethargy period. The resultsobtained suggest that this population of L. cuyanus has a seasonal reproductive cycle, with its reproductiveactivity occurring during the spring-summer months (PrR-R periods) and finishing in late summer (PsR).