Reproductive biology of Phymaturus cf. palluma, an endangered lizard from the highlands of the Andes, San Juan, Argentina

CARTES, F.; BORETTO, J.M.; ACOSTA, J.C.; JAHN, G.A.; BLANCO, G.; LASPIUR, A.; IBARGÜENGOYTÍA, N.R.

Herpetological Conservation and Biology

Springs Preserve

Año: 2010 vol. 5 p. 430 - 440

1931-7603

Viviparous liolaemids that inhabit cool and harsh environments of Patagonia and the highlands of the Andes have exhibited distinctive life-history traits to synchronize the births with benign environmental conditions. We studied the reproduction of Phymaturus cf. palluma, a viviparous species that inhabits rocky outcrops in cool environments of the Andean highlands of San Juan, Argentina, and determined how the characteristics of the reproductive cycle affect the conservation status of the species. We determined male and female reproductive cycles, male testosterone cycle, allometry of morphometric variables and sexual dimorphism, minimum adult size, clutch size, and mean annual reproductive output.  Females of Phymaturus cf. palluma exhibited a biennial reproductive cycle, with a clutch size of one to two offspring, resulting in a low mean annual reproductive output: 0.75 offspring/female/year. The male spermatogenic cycle was asynchronous among individuals.  We observed males with sperm in the epididymis and high values of serum testosterone concentration throughout the activity season. The sexual dimorphism and the allometric analyses revealed that legs are wider in males than in females throughout the life span, and not linked to sexual maturity.  In contrast, the head size in males and the trunk size in females are developed after sexual maturity, suggesting that they have arisen through sexual selection. The present study confirmed a pattern of prolonged female cycles and low mean of annual reproductive output in the genus Phymaturus, resulting in the study species having one of the lowest values of mean annual reproductive output for lizards in the world.