Different marine macroalgae feeding preferences of adult white-spotted rabbitfish (Siganus canaliculatus)

Abstract

White-spotted rabbitfish (Siganus canaliculatus Park, 1797) is a herbivorous fish that can be cultivated by utilizing seaweed (macroalgae) as its natural food. This study aims to determine the feed preferences of S. canaliculatus to three species of marine macroalgae. The research was conducted at The Research Center for Deep-Sea, National Research and Innovation Agency (BRIN), Ambon, Indonesia. Three species of marine macroalgae were used as test feed, namely: Ulva reticulata (Chlorophyceae), Gracilaria lichenoides (Rhodophyceae), and Padina crassa (Phaeophyceae). This research was conducted through two experimental stages. In the first stage of the experiment, each test animal was placed in three aquariums containing 3 different species of macroalgae, and in the second stage of the experiment, nine test animals were placed in nine aquariums, where each aquarium contained 1 different species of macroalgae (1 treatment with 3 tests). A completely randomized design was adopted in this study. The first experiment used one treatment three times and analyzed it descriptively. The second experiment used three treatments with three replications and was analyzed using one-way ANOVA, followed by Duncan's test. The results showed that S. canaliculatus preference to the type of macroalgae was based on consumption from the highest to the lowest, namely, P. crassa, G. lichenoides, and U. reticulata. Concurrent feeding of macroalgae resulted in a higher consumption level than single feeding. The high feed preference of S. canaliculatus based on the consumption value of marine macroalgae species was associated with high proximate content, especially protein and lipids, and tended to be inversely related to high carbohydrate content. Therefore, the selection of macroalgae species as natural feeds or as raw materials in artificial feed formulations must consider the proportion of proximate content to support optimal feed consumption by S. canaliculatus.