Food habits of the rivulated parrotfish (Scarus rivulatus) in the Seribu Islands, Jakarta

¹ Department of Aquatic Resources Management, Faculty of Fisheries and Marine Sciences, IPB University, Bogor, 16680, Indonesia.
² Faculty of Mathematics and Natural Sciences, Universitas Negeri Manado, Jl. Kampus Unima, Tondano, 95618, Indonesia.
³ Aquatic Resources Study Program, Faculty of Animal Husbandry and Fisheries, Tadulako University, Palu, 94119, Indonesia.
⁴ Department of Aquatic Resources Management, Faculty of Marine Sciences and Fisheries, Hasanuddin University, Makassar, 90245, Indonesia.
⁵ National Research and Innovation Agency, Republic of Indonesia (BRIN), Research Center for Oceanography (RCO), Jakarta, 14430, Indonesia.
⁶ Department of Biology, Faculty of Science and Technology, Universitas Jambi, Jl. Jambi-Muara Bulian, Km 15, Mendalo Darar, Jambi, 36129, Indonesia.

^* Corresponding author: onosulistiono@gmail.com

Abstract

The rivulated parrotfish (Scarus rivulatus) is one of the reef fish species from the family Scaridae and is the target catch of fishermen in the waters of the Seribu Islands, Jakarta. Information on the food habits of the parrotfish is needed as a basis for the sustainable management of the fishery resources. This study aims to analyse the food habits of this parrotfish based on sex ratio, body length, and sampling period. Sampling was conducted using muroami (mesh size = 1.5-7.6 cm) and gill net (mesh size=2-4 cm) fishing gears in the waters around Karang Congkak, Karang Bongkok, Semak Daun, Air, and Karang Beras Islands over eight months (February to September 2022). Data analyses included length frequency distribution, the index of preponderance, niche breadth, gut fullness index, food niche overlap, and hepatosomatic index. Results showed that this parrotfish is an omnivorous species that tends to be herbivorous, primarily consuming macroalgae. Diet composition changed with increasing fish length. The rivulated parrotfish belongs to a generalist group that utilizes a variety of food types and exhibits high dietary overlap between age/size groups.