INVESTIGADORES
BORETTO jorgelina Mariela
congresos y reuniones científicas
Título:
Slow life-history pattern as response to climatic harshness in Phymaturus lizards from Argentina
Autor/es:
CABEZAS-CARTES, F.; BORETTO, J.M.; IBARGÜENGOYTÍA, N.R.
Lugar:
Hangzhou
Reunión:
Congreso; 8 Congreso Mundial de Herpetología; 2016
Resumen:
Interspecific variation in life-history traits depends on trade-offs between growth, maintenance and reproduction, strongly influenced by environmental temperature in ectothermic species. In cold-climate environments species present slower growth, later sexual maturity and higher longevity than species in warm environments. Phymaturus is a vulnerable genus of viviparous and herbivorous lizards that lives in the Andes and Patagonian steppe of Argentina and Chile. Herein, we determined age at maturity and longevity and analyzed the interaction between growth and reproduction by the estimation of life-history parameters in four species of Phymaturus: P. antofagastensis, P. aguanegra (palluma phylogenetic group; high-altitude, Andean distribution), P. spectabilis and P. zapalensis (patagonicus phylogenetic group; low-altitude, Patagonian distribution). We used skeletochronology, and ages were estimated by counting the number of lines of arrested growth (LAGs) plus the estimated number of LAGs lost by endosteal resorption. Ages at maturity were similar in all species (6-7 years) except from P. zapalensis that mature later (8-9 years). Northern species like P. antofagastensis and P. aguanegra lived longer and invest more biomass in reproduction throughout their lives than Patagonian species; however, Patagonian species like P. spectabilis and P. zapalensis, invest more biomass in reproduction per year than Andean species. In spite of interspecific differences, Phymaturus exhibits a pattern of "slow" life-histories. Similarity between late ages at maturity contrasts with the variation in longevity registered, as species from the Andes highlands (3000-4000 m asl) live longer than species from the Patagonian lower lands (800-1000 m asl). Similarly, trade-offs between growth and reproduction show two patterns: on the one hand, Andean species invest more lifetime in reproduction but less energy and materials in each reproductive event; on the other hand, in the species from Patagonian steppe the shorter reproductive life is compensated by higher investment in each reproductive event and higher reproductive frequency.