Fecundity of the giant freshwater prawn Macrobrachium rosenbergii (Decapoda: Palaemonidae) in conditions of aquaculture

Abstract

Giant freshwater prawn Macrobrahium rosenbergii is one of the most prospective species of Decapoda for artificial reproduction. It is cultivated mostly in the areas with subtropical and moderate climate, but rare is grown to the maximal size. Investigations for improvement the biotechnological process of this species cultivation were conducted in Crimea in 2010-2013, in particular for the stage of early ontogenesis. In total, 245 individuals were used in the experiments. The embryonic development was divided into 5 stages. The eggs were taken from pleopods of vital females and observed by microscope with measurements by ocular micrometer and weighting. Initial realized fecundity (IRF) and finite realized fecundity (FRF) were determined by the weight method. IRF for the females with length 7.7-14.3 cm and weight 5.2-38.4 g was 3071-54692 eggs in one clutch; FRF for the females with length 7.5-14.2 cm and weight 5.3-38.1 g was 678-39925 eggs in one clutch. Both IRF and FRF increased with the length and weight of females increasing. During embryonic development, the eggs grew in 1.5 times in size and 2.1 times in weight. The volume of the eggs ovulated and just laid to pleopods was 0.08 mm³ under the temperature 24^оC and 0.06 mm³ under the temperature 28^оC.