Reproductive aspects of the freshwater prawns Pseudopalaemon bouvieri in Del Plata system

CARNEVALI R.; COLLINS P.

Coquimbo Chile

Congreso; The Crustacean Society, Summer meeting, Coquimbo, Chile, 2007; 2007

The Crustacean Society

The freshwater environments are considered unstable and with less dissolved salts than the marine systems. These conditions, among others, caused some adjustments in the physiology and biology of the organisms. The reproductive strategies and their biology played an important role so that the populations are developed successfully. The aim of the work is to identify some aspects of the biology and ecology reproductive of the freshwater prawns Pseudopalaemon bouvieri that the conquest of the freswater environments allowed. Populations of P. bouvieri of different sites of Paraná and Uruguay Rivers were sampled with bottom net (1 mm of mesh). The captured prawns were measured the cefalothorax length and determined sex. The measurement was made with a calliper under stereoscopic microscope. Also it was determined wet weight of each prawn and the gonads, then it was determined the gonadosomatic index. Ovigerous females were identified and their eggs were counted. The egg size was digitized and measured with  tpsDig. The data were evaluated statistically with variance analysis. Ovígerous females and ovaric maturation were observed in individual with 8 mm CL. The gonadosomatic index have a mean value of 0,99 ± 0,007 g increasing significantly with the female size like the eggs number. These oscillated between 11 and 79 with mean values of 39 ± 23.5 eggs. The eggs had a size means of 2,7 ± 0,67 mm in their distales polos. The completely abbreviated development of P. bouvieri characterized by great eggs and few presents characteristics similar to other species such as (P. amazoniensis) and several species of Macrobrachium.