Fish diversity of siluridae from Central Mahakam East Kalimantan Province, Indonesia

Abstract

Siluridae is a large family with varying species and sizes. Besides, many species of Siluridae are endemic and endangered. The Mahakam River in East Kalimantan is an important habitat for Siluridae, but the threat is increasing especially the construction of the New State Capital (IKN). The aims of this study were to find out the diversity of silurids from Mahakam watershed, knowing the potential and taxonomic status, also conservation status. To achieve this goal, a survey was carried out in Kutai Kartanegara Regency which is included in the Central Mahakam in June 2023. Sampling used gill nets with mesh size of 0.5-1.0 inches. Fish caught is preserved in a plastic bag containing 10% formalin solution which is equipped with a label containing the important information. Then, it is deposited in the Museum Zoologicum Bogoriense (MZB) for processing that immersing in running water, sorting, and storing in a collection bottle containing 70% alcohol solution. The next stage to identified using books and related references. Morphometric covering 20 characters, then analysis using discriminant methods. The results were caught 37 individuals from six species, namely Kryptopterus bicirrhis, Kryptopterus limpok, Ompok hypophthalmus. Ompok miostoma, Phalacronotus apogon, and Phalacronotus micronemus. Based discriminant analysis showed the six species are completely separated (100%) with the main characters viz. HL, PDL, PEL, DFH, DFBL, and PFBL. Two genera are Kryptopterus and Ompok formed group separated from Phalacronotus. All species in this study are potential as consume fish, but Kryptopterus bichirrhis has possible to develop as ornamental fish. The conservation status is mostly Least Concern (LC), except Ompok miostoma is Near Threatened (NT).