INVESTIGADORES
CABEZAS CARTES facundo
artículos
Título:
Energy allocation to growth and reproduction in a viviparous lizard endemic to the Highlands of the Andes, Argentina
Autor/es:
BORETTO, JORGELINA; CABEZAS CARTES, FACUNDO; IBARGÜENGOYTÍA, NORA
Revista:
JOURNAL OF ZOOLOGY (1987)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2015
ISSN:
0952-8369
Resumen:
Individuals devoted energy intake to growth, maintenance and reproduction, so knowing the way in which they use this energy between competing demands is essential to study their relationship with their environment. Phymaturus lizards, viviparous and mostly herbivorous, inhabit cold and harsh environments of the Andes of Argentina and Chile, and the volcanic plateaus of Patagonia. Herein we discussed the interplay between reproductive effort and growth in Phymaturus punae, a lizard with a biannual female reproductive cycle and the lowest annual reproductive output of the genus. Using skeletochronology, we estimated that juvenile?s age ranged from 6-9 years, adult female?s ages ranged from 8-18 years, and adult male?s ages ranged from 9-20 years. Juveniles grow faster than adults, and adult females have higher specific growth rates than adult males. The adult life span was 10 years for females and 11 for males, and the relative reproductive time was 1.25 for females and 1.22 for males. Net reproductive rate resulted in 7.5 offspring throughout the females? reproductive life. During adulthood a negative correlation was found between the ring width and age in males, while in females the ring width was not correlated with age. Females tend to have wider rings the years that were pregnant and narrower rings the years that performed vitellogenesis. The intersexual differential investment in growth is congruent with differential requirements for reproduction between males and females, whereas the differential investment in growth between vitellogenic and pregnant females suggest differences in the metabolic costs of these reproductive processes. Even when P. punae exhibit high life span, females have a relative low lifetime reproductive effort and net reproductive rate. However, this still represents a high reproductive investment for this species, considering the harsh conditions of the environments where it lives, the viviparous reproductive mode, and the herbivorous diet.