Genetic diversity of six populations of Ajamaru rainbowfish (Melanotaenia ajamaruensis) with different breeding ratios

Abstract

The Ajamaru rainbowfish (Melanotaenia ajamaruensis) is a West Papuan endemic and has been successfully cultured. The study aims to determine the genetic diversity of the Ajamaru rainbowfish ornamental fish populations that breed with differences in the breeding ratio to offspring. Tail fin samples were taken from six populations of Ajamaru rainbowfish consisting of 2 generations for DNA extraction. Three-broodstock populations (1:1, 1:2, and 3:1) spawn at seven months old, and three offspring populations. The method used was Randomly Amplified Polymorphic DNA (RAPD) analysis, primary screening using 20 primers, and four selected primers (OPG 2, OPB 6, OPH 5, and OPZ 9). Data analysis used TFPGA software to generate genetic diversity values in heterozygosity and polymorphism. The results showed the lowest genetic diversity in population 1, with polymorphism (46.99%) and heterozygosity 0.1894. The highest genetic diversity was in population 4, with descendants with polymorphism (78.31%) and heterozygosity of 0.2922. Relationships among 6 Ajamaru rainbowfish populations formed two clades based on their generation. Improving genetic quality in the breeding of Ajamaru rainbowfish can be done through selective breeding with a breeding ratio of 1:1 or the full-sib broodstock for higher genetic diversity values.