Response to environment condition and isolation of populations of the freshwater prawn Palaemonetes argentinus through of shape.

TORRES, M.V.; GIRI, F.; ITUARTE, R. B.; RUMBOLD, C.; VÁZQUEZ, M. G; COLLINS, P.

Barcelona

Congreso; The Crustacean Society Mid Year Meeting 19-22 June 2017 Barcelona-Spain; 2017

Environmental variation leads to differences in population structure, including morphological heterogeneity, together the elapsed time of disconnections of the populations. Also, a number of contaminants of agriculture activity have been shown to impact crustacean growth, size, reproductive capacity, and survival. The aim of this work was to study the shape variations in the freshwater prawn Palaemonetes argentinus in environments with different abiotic conditions and elapsed time of disconnection of their populations. Distant populations that range from 20 km and 900 km approximately were used to compare their shapes with geometric morphometrics tools. The sites correspond to Pampean basins and distinct subbasins of Paraná River (different in conductivity and agriculture activity). Configurations of 15 landmarks were analyzed and digitised to represent the lateral cephalothorax. Shape variations were explored by Principal Component Analyses. Then Canonical Variate Analyses was applied to compare the shape between prawns of sites. The PC1 showed the variations among prawns shape of basins. The Pampean basins were different to the distinct subbasins of Paraná River. In the first group of populations, the individuals were smaller than those belonging to the distinct subbasins of Paraná River. It was reported intraspecific variation of the allometry according to environments with different abiotic conditions. This species originated off the sea, living in brackish or estuarine waters and their conquest of the continental environments occur in recent evolutionary times. This suggests adaptations of this species to different freshwater environments throughout their evolutionary course with the expression of their shapes, growth and reproduction dynamics.