Abstract:
Attractive coloration is a decisive factor determining the market value of ornamental fish. As
usage of dietary synthetic carotenoids to enhance coloration in ornamental fish is expensive,
many research has focused on the increment of coloration of them by using natural carotenoid
sources. The present study was carried out to elucidate the effect of papaya peel (Carica papaya)
powder on color enhancement, growth performances and feed utilization of Swordtail fish
(Xiphophorus helleri). Three experimental diets (30.4% crude protein, 4.9% crude lipid) were
formulated and labeled as CT (Control diet - 0% papaya peel powder), PP4 (diet with 4% papaya
peel powder) and PP8 (diet with 8% papaya peel powder). Juvenile fish (1.35±0.10cm;
0.21±0.01g) were stocked in 9 glass tanks (20L; 15 fish/tank) and fed with experimental diets
twice a day ad libitum for 42 days. At the end of the experimental period, fish fed with PP4
(3.75±0.22cm, 1.21±0.10g) diet recorded significantly higher live weight compared to other two
treatments and there was no significant difference in Feed conversion Ratio (1.53 - 1.87) and %
Specific Growth rate (3.77 - 3.80) among all three treatments. Further, % Average Daily Gain of
fish in PP4 (11.43 ± 0.26) and PP8 (11.02 ± 0.26) treatments had no significant difference but
showed a significant difference with that of fish in CT (7.29 ± 0.52) treatment. Carotenoid content
of fish tissues (6.62 ± 0.23) was significantly higher in fish in PP4 treatment compared to that of
other two treatments. The survival rate (91 – 100%) was good in all the treatments. In conclusion,
the present findings established that among the diets tested, the diet containing 4% of the papaya
peel powder (PP4) showed better growth performance and maximum enhancement of coloration
in Swordtail fish (Xiphophorous helleri).
