Population Genetics Analysis of M. gulio in Three Rivers in Pasuruan, East Java Using COI

Document Type : Original Article

Authors

1 Department of Aquatic Resource Management, Faculty of Fisheries and Marine Science, Universitas Brawijaya, Indonesia

2 Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Brawijaya, Jl. Veteran, Malang 65145, East Java, Indonesia

3 Faculty of Fisheries and Marine Sciences, Universitas Brawijaya, Jl. Veteran, Malang 65145, East Java, Indonesia, Tel/fax: +62-341-553512

4 Polytechnic of Marine and Fisheries Sorong, Southwest Papua, Indonesia

5 Aquaculture Study Program, Bangka Belitung University, Bangka 33172, Indonesia

6 Department of Fisheries and Marine Resources Management, Faculty of Fisheries and Marine Sciences, Universitas Brawijaya

7 Marine Science Program, Faculty of Science and Technology, State Islamic University of Sunan Ampel, Surabaya, East Java, 60237, Indonesia University

10.21608/ejabf.2025.439184.6934

Abstract

The study of aquatic environments can be conducted through the organisms that inhabit them, one of which involves a population genetics approach. Population genetics has been widely applied to various taxa, including fish; however, this approach remains very limited for keting catfish (Mystus gulio), especially in Pasuruan. Previous research has examined the environment and morphology of M. gulio in three Pasuruan rivers—Rejoso, Welang, and Gembong—but no population genetics study of M. gulio in Pasuruan and the surrounding areas has been conducted. Genetic analysis using the mitochondrial DNA (mtDNA) region of cytochrome oxidase subunit I (COI) can support molecular identification, as well as the estimation of genetic diversity and population structure. Sampling was carried out in three rivers in Pasuruan; the fish were preserved, and DNA extraction was performed up to the sequencing stage. Sequencing results were analyzed using BLAST identification, haplotype network analysis, phylogenetic trees, genetic p-distances, and pairwise Fst. The genetic diversity of M. gulio in each river in Pasuruan was low, with a nucleotide diversity (Pi) value of 0.00068 and a haplotype diversity (Hd) value of 0.400. Misidentifications in GenBank based on BLAST results for the Cilacap population were corrected using the haplotype network and phylogenetic tree generated in this study. The populations from each river are likely still connected, including those in Cilacap, as indicated by an Fst value of 0. It is possible that M. gulio migrates via the sea, as suggested by the low genetic distance (1.7%) between the Indonesian and Indian populations. Several overlaps were observed, which may represent a taxonomic conundrum.

Keywords