Benthic invertebrates community in artificial substrates in Lake Maninjau, West Sumatra

Abstract

Abstract. Imroatushshoolikhah, Ibrahim A, Sudarso J. 2019. Benthic invertebrates community in artificial substrates in Lake Maninjau, West Sumatra. Pros Sem Nas Masy Biodiv Indon 5: 340-346. The littoral zone is a productive part of the lake. Buoyant Fish Attractor (BFA) is a technology that is installed in the littoral zone of Lake Maninjau in an effort to provide a new microhabitat for aquatic biota. One of the important biotas monitored in this BFA system is an invertebrate group. The group, especially the insect, is a source of food for local fish in Lake Maninjau. Artificial substrate for invertebrates with dimensions of 21 x 30 x 7 cms was assembled in three of the base BFA with a distance of about ± 70 cm from the surface of the water and ± 1.5 m from the bottom of the water. This study aims to determine the structure of invertebrate communities that colonize artificial substrates in the littoral zone of Lake Maninjau. Invertebrate sampling is carried out from July to September 2018 on each artificial substrate attached to the BFA. Benthic invertebrates samples are filtered, then preserved with 10% of formaldehyde. The results showed that there were a total 17 taxa of benthic invertebrates found on artificial substrates which attached in BFA. The group consists of Crustaceans, Insects, Oligochaetes, Molluscs, and Euhirudinea. Crustaceans (Ostracods) are the main colonizers of artificial substrates. The diversity of benthic invertebrates found was relatively low with the Shannon-Wiener Diversity index, ranged between 0.241 to 0.696, While the Evenness index ranged between 0.285 to 0.77. The Bray-Curtis similarity index showed that the benthic invertebrates who colonized three artificial substrates have a considerable degree of similarity. It can be concluded that, the artificial substrates which installed in the littoral zone of Maninjau Lake is capable of creating new microhabitat for invertebrates, especially Crustaceans (Ostracoda) and Insects.