Research Information System
PAKISTAN JOURNAL OF ZOOLOGY, vol.54, no.6, pp.1-10, 2022 (Journal Indexed in SCI)
This 40-day feeding trial was aimed to determine the effective rate of L-carnitine on the growth of electric
yellow cichlid (Labidochromis caeruleus) fry (n: 395, initial weight:0,46 g, initial length: 2.5 cm). They
were randomly placed in 50 l aquariums. Based on the basal diet (55% crude protein+14% oil), the four
experimental diets were designed with supplementation of L-carnitine (0, 500, 1000, 2000 mg/kg). They
were fed 10% of their weight every day. Sampling was done at the beginning and the final day of the
experiment for digestive enzymes (protease, lipase, amylase), weight and length, body colour and survival
rate. The image analysis method was used to determine skin colour. The chemical analysis method was
used to determine the activity of enzymes. The results showed that supplementation of 2000 mg/kg of
dietary significantly increased weight, length and specific growth rate (P < 0.05). While no change in
colour was observed in the control group at the end of the experiment, it was determined that carnitine
could have a 27% effect on the colour change of fish in the other groups. Better results were obtained
between the L-carnitine groups compared to the control group for in terms of digestive enzymes, while
and the difference between the groups was found to be statistically significant (p≤0.05). The results
show that L-carnitine did not play an important role in the survival of fish. As a result, the addition of
L-carnitine to fish feed positively affects the growth of fish and as expected, the growth of fish increases
as the amount of L-carnitine in the feed increases.