Effect of long‐term injection of dopamine on the ovarian growth of C herax quadricarinatus juvenile females ( P arastacidae, D ecapoda)

Abstract

The neurotransmitter dopamine ( DA ) modulates many physiological processes in decapod crustaceans, including reproduction. This study was aimed at evaluating whether the long‐term injection of DA affects ovarian growth in the freshwater crayfish C herax quadricarinatus . Three experiments were performed with females of different mean initial size: 4.15 g (Group A ); 9.65 g (Group B ); and 13.98 g (Group C ). Treated females were injected with DA and control females with physiological saline twice a week for 90 (Group B ), 105 (Group A ) and 120 (Group C ) days. At the end of the experiments, the animals were killed, and the stage of ovarian development, gonadosomatic index, and mean oocyte diameter were determined. DA had a differential effect according to female size: it negatively affected ovarian growth of females in a weight range of 4–14 g and had no effect on ovarian maturation when injected to females with an initial weight of 14 g. The results are compared with previous reports in freshwater decapod crustaceans.