The ripe females have conspicuous orange
gonads visible through the dorsal and lateral sides
of the carapace. Mating usually occurs within
24 h, of the pre-spawning moult of the female
prawns (Rao 1965; Wickins & Beard 1974). Mating
takes place between hard-shelled males and
ripe-soft-shelled females which have completed
their pre-mating moult. The fertilized eggs become
attached to each other and the setae of the first
pleopods by a cementing substance (Pillay 1993).
Mating of Macrobrachium sp. has been accomplished
under laboratory conditions and described
by several authors (Ling 1969; Chow, Ogaswara &
Taki 1982 for M. rosenbergii, Choudhury 1971 for
Macrobrachium acanthurus, Ching & Velez 1985 for
Macrobrachium heterochirus and Soundarapandian
& Kannupandi 2000; Soundarapandian 2008 for
Macrobrachium malcolmsonii and M. rosenbergii).
The colour of the eggs in M. rosenbergii is deep
orange, yellow and become dark grey corresponding
to embryonic development (Prasad & Kanaujia
2006).