Pre-mating moult and breeding behaviour
The adult males and females were given a dip
bath in 0.5 mg L1 potassium permanganate solution
(KMnO4) for 5 min. After that they were
transported to large glass aquaria (50 9 40
9 30 cm) filled with dechlorinated tap water to
carry out the pre-mating moult, breeding behaviour
and mating process (sex ratio 1 male:3
females). The water in each aquarium was continuously
aerated by means of an electric air pump
and was partially changed daily and completely
each week, throughout the investigation period.
Plastic pipes were placed in all aquaria to serve as
a shelter for protection of pre-mating moult
females from predators. Female prawns were
inspected each day for signs of maturity. Ripe
females were recognized by the conspicuous
orange gonads visible through the dorsal and lateral
sides of carapace.