Mosquitofish life history in a Mediterranean wetland

Little is known regarding the life history of Gambusia holbrooki in Europe, particularly in Italy, where it has been introduced in several wetlands since 1922. In order to increase the knowledge of its biology, we tried to clarify its life history in a Mediterranean wetland, comparing our results with those of other authors. The principal aim of this study was to describe the demographic potentialities of the studied population by modal progression analysis. Besides the curvature parameter ( 0.52 and 0.51 for females and males, respectively) and the asymptotic length values ( 39.01 and 30.45 for females and males, respectively), we observed a population divided into four age classes, for both sexes, and a longevity of 5 years, with only a limited number of mosquitofish reaching this age ( due to a high mortality rate). In addition, reproduction observations were carried out for females. The most interesting aspect concerned the correlation between fecundity and body size, and the capacity of small females to absorb fertilized eggs.