Induced breeding and larval rearing
The fi sh attain maturity weight of 30-40 g at the end of fi rst
year of its life. Males mature earlier than females. Fertilisation
is external and spawning occurs once a year during the
monsoon months, June through to August.
Butter catfi sh are hatchery bred in Bihar, West Bengal and
north-eastern states such as Tripura using pituitary gland
extract, ovaprim and ovatide as inducing agents. In Tripura,
fi sh of 35-100 g and more than one year in age are used
as broodstock. Ovaprim is injected at a dosage of 1-1.5 ml/
kg body weight for females and 0.5-1.0 ml/kg body weight
for males. Females are stripped for spawning 8-10 hours
after hormonal injection. The numbers of eggs produced
varies from 3,000-4,000 per female weighing 30-50g. Milt is
collected from males by surgically removing their testes and
macerating them. This is mixed together with the eggs using
a feather for their fertilisation. The eggs are subsequently
washed thoroughly with clean water and transferred into a
masonry tank with clean water for hatching.