Empirical feed formulations for the marine ornamental fish,striped damsel,Dascyllus aruanus (Linné 1758) and their physical,chemical and nutritional evaluation

Formulated feeds containing a common ingredient mixture (CIM) consisting of fishmeal (anchovies), shrimp meal (Acetes), squid meal (Loligo) and soybean meal incorporated in ascending levels to obtain protein levels ranging from 180 to 560 g kg^?1(18.34%, 25.35%, 36.27%, 46.61% and 56.28%) and an energy level of 19 MJ kg^?1 were fed to the marine ornamental fish, striped damsel, Dascyllus aruanus <200 mg and 200–300 mg in size for periods of 35 and 63 days. The <200 mg fish accepted particles <0.5 mm in size and showed maximum growth in terms of absolute growth rate (AGR), relative growth rate (RGR) and specific growth rate (SGR) with the feed containing 380 g kg^?1 CIM having a protein content of 362 g kg^?1. Second‐degree polynomial regression equations fitted confirmed these observations with a predicted requirement of 360 g kg^?1 protein. In fish weighing 200–300 mg, growth was not significantly different (P>0.05) in fish fed with feeds containing 380 and 580 g kg^?1 CIM with 360 and 470 g kg^?1 protein. With these data, the second‐degree polynomial regressions showed that a protein level of 464 g kg^?1 would result in an RGR of 107%. The feeds were well accepted by the damselfish, showing good colour retention and health.The cost of the feeds excluding processing costs ranges from US $ 1.35 to 3.36 kg^?1. This is the first report on the development of formulated feeds for damselfish that would help in rearing and aquarium keeping of damselfish worldwide.