Feeding preference of white spotted rabbitfish (Siganus canaliculatus) on different species of seagrass

Abstract

The white-spotted rabbit (Siganus canaliculatus) is a group of marine herbivorous fish that has the potential to be cultivated. One of the natural food is seagrass. The purpose of this study was to analyze the feeding preferences of S. canaliculatus on different species of seagrass. This experimental study used S. canaliculatus and four types of seagrass (Enhalus accoroides, Thalassia hemprichii, Cymodocea rotundata, Cymodocea serrulata) as test feed. An 80 L aquarium with an aquaculture recirculation system was used as a rearing tank. The study was carried out in 2 experimental stages, namely: 4 species of seagrass were placed in the same rearing container (Experiment I), and 4 types of seagrass were separated, each in a different rearing container (Experiment II). A total of 1 individual fish was put into each container. Feed consumption was recorded every 24 hours, each experiment was carried out for 3 days (72 hours). This study used a completely randomized design (CRD). Experiment I used one treatment with three replications and the data were analyzed descriptively. Experiment II used four treatments with three replications and the data were analyzed using one-way ANOVA and Duncan's test to determine further differences. The results showed that S. canaliculatus preferred seagrass feed, respectively, C. serrulata, C. rotundata, T. hemprichii, and E. acoroides. Different seagrass feed preferences are thought to be related to 1) proportional proximate composition, 2) protein to energy and higher GE/P ratio, and 3) low content of secondary metabolites (tannins). Thus, C. rotundata and C serrulata can be used as the main ingredients for making feed formulations for S. canaliculatus.