Particulated microalgae composite (PMC) as live microalgae substitute of juvenile Manila clam Ruditapesphilippinarum: A feasibility analysis

To evaluate the feasibility of particulated microalgae composite (PMC) as live microalgae substitute in artificial breeding of Manila clam Ruditapes philippinarum, effects of replacing Dicrateria inornata with partial or total PMC on the growth, digestive enzyme activities, nutritional ingredient composition and microbial composition in feces of juvenile clams were investigated. The results showed 50% and 100% PMC replacement didn't affected the mean shell length, mean body weight and survival rate of juvenile clams (P>0.05). Juvenile clams fed with 100% PMC replacement had higher lipase and pepsin activities than those fed with 100% D. inornata (P<0.05), while 50% PMC replacement only increased lipase activity (P<0.05). Essential amino acid (EAA) and polyunsaturated fatty acid (PUFA) contents exhibited no obvious differences between clams fed with and without PMC replacement (P>0.05). 100% PMC replacement could significantly increase delicious amino acid contents (P<0.05). PMC replacement did not affect the diversity of dominant phyla in feces, but the abundance of each dominant phylum. Similar relative abundance of fecal bacteria functions was observed when D. inornata was replaced with 50% and 100% PMC. PMC appeared to be a potential microalgae substitute in artificial Manila clam breeding.