Maintaining good water quality was the major challenge in
the present study. Exchange of water during larval rearing was
imperative and resulted in better survival of larvae. Maintenance
of light and dark period is an important factor during
larval rearing. Insufficient photoperiod may result in ‘head
butting syndrome’ and starvation, which may lead to the death
of larvae ultimately. However, 10–20% of larval mortality was
observed during 1st and 2nd days after hatching and it was
unavoidable. This mortality may be due to the stress and injury
caused during larval transfer from the parent tank to
the larval rearing tank or due to difficulties in accepting the
first feed. Mortalities were also observed during the time when
larval feed was changed from rotifers to Artemia. It was also
observed that un-hatched Artemia cysts blocked the digestive
tract of larvae and interfered with the digestive process. The
main infection faced by juveniles during rearing was the marine
white spot disease. The treatment given was fresh water dip
for 1 min with vigorous aeration.