Portal de Periódicos da CAPES

Growth and Population Structure of Red-Spotted Newts (Notophthalmus viridescens) in Permanent Lakes of the Laurentian Shield, Quebec

1996; American Society of Ichthyologists and Herpetologists; Volume: 1996; Issue: 4 Linguagem: Inglês

10.2307/1447649

1938-5110

Maria Helena Caetano, Raymond Leclair,

Ecology and biodiversity studies

We sampled adult populations of the red-spotted newt (Notophthalmus viridescens) from five permanent oligotrophic lakes of the Mastigouche Reserve (Quebec) to document the plasticity of certain life-history traits. We assessed age and growth by skeletochronology and back-calculation methods. Regardless of whether populations were analyzed separately or together, age (2-13 yr) was correlated with snout-vent length (34-54 mm). Females tended to be larger than males in three lakes either because they were older or because they grew faster. Males appeared to mature at younger ages and smaller body sizes than females. Age structure showed significant interpopulation differences: adults were between three and nine years of age with a modal frequency of four years in two lakes, and between four and 13 years of age with a modal frequency of seven years in another lake. Populations in two lakes were intermediate in age structure. Newts in one lake were characterized by high growth rates in the first three years of life, but, as adults, they showed lower values of mean age and body size compared to specimens in other lakes. Resource abundance, an interaction between growth rate and maturation, and evolutionary responses to different predatory fish communities may be potential causes for the observed divergence in life-history traits among populations.