Conserving the genetic resources of Rita rita: A GIS-mapping based approach

Abstract

Understanding the genetic status and spatial distribution of fish species is essential for the conservation and management of their genetic resources. Anthropogenic factors, including hydrological alterations, pollution, overexploitation, deforestation, and the introduction of non-native species, have led to a gradual decline in genetic diversity. In this pioneering study, we investigate the integration of genetic diversity data with spatial statistical tools to map the genetic diversity of wild Rita rita stocks in the River Jhelum, Pakistan. Samples were collected from eight selected sites, and cross-species amplification was conducted using ten microsatellite loci. The Inverse Distance Weighting (IDW) algorithm was applied in ArcGIS 10.2 to generate genetic diversity maps. The study recorded the number of alleles (Na) and allelic richness (Ar) ranging from 3.20 to 4.00, for both Na and Ar. The effective number of alleles (Nae) averaged between 2.459 and 3.506, while observed and expected heterozygosity ranged from 0.640 to 0.724 and 0.526–0.665, respectively. Inbreeding coefficient values varied from −0.077–0.115. A significant departure from Hardy-Weinberg Equilibrium (HWE) was noted in 17 out of 80 tests. Statistically significant F_ST values demonstrated significant differentiation among population pairs. Analysis of Molecular Variance (AMOVA) indicated that only a small percentage (3.911 %) of the variation existed among stocks. The findings reveal a low level of genetic diversity in the assessed fish stocks, likely attributed to changes in stock dynamics due to climate change and genetic drift resulting from habitat fragmentation. Understanding the genetic structure of R. rita stocks offers valuable insights for genetic improvement programs, effective management practices, and the long-term preservation of riverine genetic resources.