Research Information System
Journal of FisheriesSciences.com, vol.3, no.2, pp.146-152, 2009 (Peer-Reviewed Journal)
A growth trial was conducted in order to determine the effects of increased photoperiod regimes
on growth performance, feed intake and survival of mirror carp (Cyprinus carpio Linnaeus,
1758) in laboratory conditions for 90 days. Triplicate groups of fish (6 g mean body
weight) were exposed to photoperiod regimes of 12 hours light:12 hours dark (12L:12D), increased photoperiods of 16 hours light:8 hours dark (16L:8D) and continuous light (24L:0D),
respectively. At the end of the trial, growth was highest in the group subjected to continuous
photoperiod, and appeared significantly different (p<0.05) than the rates recorded in the other
photoperiod regimes. Under the continuous (24L:0D) photoperiod, feed conversion ratio (FCR)
was significantly (p<0.05) better than those in the other photoperiod treatments. No significant
difference (p>0.05) was found in the FCRs between the 12L:12D and 16L:8D groups. Feed
intake was not significantly (p>0.05) affected by photoperiod treatments. No mortality was observed in the continuous (24L:0D) photoperiod group, however, a mortality of about 3 % was
recorded in the other two groups. For a better growth and lower food conversion rate, a continuous (24L:0D) photoperiod exposure is suggested best for rearing of juvenile carp.