Abstract:
The skin and fin color of ornamental swordtail fish (Xiphophorus helleri) is an important factor
affecting their market value. This 84-day feeding trial aimed to evaluate the effects of dietary
supplementation with pumpkin (Cucurbita maxima) flower powder on the coloration and growth
performance of juvenile swordtails. The fish (Number of fish 90) with an initial average length of
2.020 ± 0.04a cm and weight of 0.097 ± 0.01a g were stocked into nine glass tanks (1.5 ft x 1.5 ft x
1 ft) at a density of 10 fish per tank. Three diets were formulated with equal amounts of proximate
composition: a control diet without pumpkin flower powder (Diet CT), and diets containing either
2.5% (Diet PF2.5) or 5% (Diet PF5) pumpkin flower powder. Each diet was fed to fish in
triplicate tanks. At the end of the trial, fish fed Diet PF5 had significantly (P<0.05) greater final
length (6.678 ± 0.41a cm) and weight (5.193 ± 0.31a g), specific growth rate (5.936 ± 0.23a %/day),
average daily gain (76.4 ± 13.7a %), and better feed conversion ratio (3.407 ± 0.01a) compared to
the other diets. The final carotenoid content varied significantly among the three treatments: Diet
CT (14.881 ± 0.29c), Diet PF2.5 (70.141 ± 0.85b),and Diet PF5 (85.47 ± 0.44a), indicating notable
differences in carotenoid levels obtained. Skin and fin coloration demonstrated a positive
correlation with the increment in dietary pumpkin flower powder. Higher muscular carotenoid
content in fish-fed pumpkin diets indicated absorption and utilization of carotenoids supplied
through the diets. The significant improvement in growth performance and color with Diet PF5
makes it a good solution for enhancing the commercial value of ornamental swordtails.
