Effect of the varying inclusion levels of the egg yolk powder on growth, stress tolerance, and pigmentation of Guppy (Poecilia reticulata)

ABSTRACT The newly hatched nauplii of Artemia is extensively used as a live feed for ornamental fish hatchlings; however, its high cost and unbalanced nutrients necessitate exploring sustainable alternatives. An experiment was conducted to evaluate the effects of four formulated diets of 0%,5%, 10%, and 20% inclusion levels of egg yolk powder and other ingredients (fish meal, soybean meal, rice polish, corn) during the nursery stage of Guppy (Poecilia reticulata) compared to Artemia salina as a control. Results showed that survival did not differ (P > 0.05) among the diets. Weight gain, daily weight gain, and specific growth rate of the fry fed with 10% egg yolk-included diet containing 49.6% fish meal and 18.8% soybean meal were significantly higher (P < 0.05) than those of the other test diets and the A. salina. All the diets showed higher stress indexes (P < 0.05) than the control; the test diets did not affect pigmentation.