The effect of differences in feed protein raw materials on the glycogen content, metamorphosis rate of mangrove crab larvae (Scylla olivacea) and feed price

Abstract

Feed is one of the factors that determine the success of rearing mangrove crab larvae (Scylla olivacea). The use of artificial feed in the form of micro diet can guarantee higher availability and flexibility of feed. The artificial feed generally used is commercial produced and relatively expensive; therefore research is needed to produce good quality artificial feed at low prices. This study aimed to determine feed with certain protein raw materials that can replace commercial feed in terms of glycogen content of larvae, metamorphosis rate and feed price. The experimental design to determine the treatment effect on larval glycogen content was a completely randomized design of eight treatments with three replicates. The treatments were: A) 100% Artemia meal, B) 100% fish meal, C) 100% squid meal, D) 50% Artemia meal, 50% fish meal, E) 50% Artemia meal, 50% squid meal, F) 50% fish meal, 50% squid meal, G) 35% fish meal, 35% squid meal, 30% Artemia meal as raw material for feed protein and H) commercial feed. The rate of metamorphosis and price of feed were analysed descriptively. Results of the variance analysis showed that the difference in feed protein raw material had a significant effect (p<0.05) on the glycogen content of the megalopa stage larvae. The glycogen content in treatments C and E was not significantly different (p>0.05) but was higher and significantly different (p<0.05) than other treatments. Mangrove crab larvae in treatments A, C, E and F have reached the megalopa stage at the age of 18 days, while other treatments have only reached the new megalopa stage when the larvae were 19 days old. The lowest production cost of making the low budget feed is feed with protein raw material in the form of 100% fish meal and the most expensive one is feed with 100% raw material Artemia meal. Based on the result of this study, feed with protein raw material in the form of 100% squid meal can be used as a substitute for commercial feed, besides providing a better response to glycogen content and metamorphosis rate, the price of this feed is also cheaper than commercial feed.