Journal of the Marine Biological Association of India

Transoceanic genetic diversity of milkfish, Chanos chanos (Fabricius, 1775), based on cyt b sequence analysis

Volume 67 Issue 1

Divya Merin Jose, Magdeline Christo and P. R. Divya

doi:10.6024/jmbai.2025.67.1.2566-01

Abstract

The genetic structure of milkfish (Chanos chanos), an economically important aquaculture species, was examined across four populations in the Indo-Pacific region: French Polynesia, India, Indonesia, and the Philippines. The mitochondrial cytochrome b sequences of 99 individuals from India were compared with data from 268 individuals from French Polynesia, Indonesia, and the Philippines, providing a broad representation of the species across the region. Within these four populations, 73 unique haplotypes were identified, with the Indian populations exhibiting the highest levels of gene diversity (0.798) and low nucleotide diversity (0.003). In contrast, the Indonesian populations showed the lowest levels, with values of 0.520 and 0.001, respectively. An analysis of molecular variance (AMOVA) unveiled that 95.53% of the genetic variation resided within populations, while only 4.46% was attributed to differences among populations. Hierarchical AMOVA and pairwise F_ST analyses indicated significant genetic differences among Group I, II and III populations in the Indo-Pacific region. These findings highlight the importance of coordinated regional strategies for the effective and location-specific management of milkfish stocks across this region. The haplotype network exhibited a star-like genealogical pattern, indicative of a demographic expansion within the milkfishpopulations across these locations. These findings were further corroborated by Tajima’s D statistics. With its significant findings, this study not only delineates the genetic structure of this important species in the Indo-Pacific region but also provides a valuable resource for fishery stock identification, facilitating effective management strategies and conservation efforts.

Keywords

Cyt b, genetic stock structure, Indo-Pacific, mitochondrial markers

Date : 13-06-2025