Abstract:
A six-week feeding trial was conducted to investigate the effects of three experimental feeds on 
growth performance and feed utilization, survival and coloration of platy fish, Xiphophorus sp. The 
Prima diet was used as the control diet (CD) with no additives and two experimental diets were 
prepared by supplimenting 5% shrimp shell powder (SD) and 5% garlic powder into a base prima 
diet (GD). Triplicate groups of platy fingerlings (0.34 ± 0.01 g, 2.25 ± 0.12 cm) were stocked in 
nine glass aquaria (60 × 30 × 40 cm³), at a density of ten fish per tank. Fish were fed ad libitum 
twice daily and growth performance (total length, total weight, weight gain%, length gain%, 
average daily gain%, specific growth rate%), feed utilization ratio (FCR) and coloration level 
(total carotenoid content) were evaluated. Fish fed the diet supplemented with shrimp shell 
powder (SD) exhibited significantly higher (p<0.05) growth performance, including final body 
weight (0.84±0.10g), total length (3.28 ±0.06cm), specific growth rate (2.39 ±0.04%) and average 
daily gain (3.49±0.7%) compared to those fed the CD or GD. Survival rate did not differ 
significantly (p>0.05) among treatments. Hepatosomatic Index (HSI) and Gonadosomatic Index 
(GSI) were significantly higher (p<0.05) in SD treatment. Skin and caudal fin carotenoid content 
was highest in the SD group (4.01 ± 0.12 mg/kg), followed by the GD (3.58 ± 0.13 mg/kg) and CD 
(3.14 ± 0.06 mg/kg) groups. The results indicate that dietary supplementation with 5% shrimp 
shell powder significantly enhances growth and coloration in platy fish. Therefore, shrimp shell 
powder has potential as a valuable additive in fish diets for both growth promotion and color 
enhancement, benefiting the ornamental and food fish industries.