Influence of female size on offspring quality of the freshwater crayfish cherax quadricarinatus (Parastacidae: Decapoda)

Abstract

Knowledge on maternal influences in offspring quality of decapod crustaceans is limited, especially for freshwater species. We investigated the effects of female body weight on production variables (actual fecundity, AF), morphological/morphometrical features of eggs (volume, wet and dry weights) and recently independent juveniles (size, weight), and on juvenile growth performance and survival in the freshwater crayfish Cherax quadricarinatus (von Martens, 1868), under laboratory conditions. For this purpose, two groups of females were used: "large females" weighing 50-70 g; and "small females" weighing 20-35 g. The AF was the only production variable that increased with female weight. The percentage of ovigerous females also tended to increase with female weight: the 73% of "large females" and the 57% of "small females" spawned once. The remaining features did not vary with female weight. These results indicate that under controlled and constant laboratory conditions the egg and juvenile quality are similar between "small females" and "large females," an important outcome both from a theoretical and an economical point of view. In particular, this is the first report on the absence of correlation between maternal weight and juvenile size in a decapod crustacean with direct development. The results are compared with previous studies mainly in marine decapod species with indirect development.