Genetic Integrity in Wild Stock of Babylonia spirata (Linnaeus, 1758) and Babylonia zeylanica (Bruguiere, 1789) from Southeast Coast of India: An important Mariculture Gastropod Species

Abstract

Background/Objectives: Determining the effect of high demand of whelk meat, overexploitation and indiscriminate fishing on the genetic diversity in two economically important whelk species viz., Babylonia spirata and Babylonia zeylanica from southeast coast of India. Methods/Statistical analysis: The genetic diversity and population structure of two whelk species namely, B. spirata (62) and B. zeylanica (57) involving total 119 individuals were studied using standard diversity parameters. Both species were genotyped at 12 microsatellite loci to support conservation and improvement strategies. Findings: The results show that levels of genetic diversity in natural populations of specific genetic group are moderate to low. All the loci under study were observed to be highly polymorphic and a total of 139 alleles for all 12 markers were identified. The two genetic groups of the whelk species presented HWE deviations for majority of the loci. The range of alleles was found to be 3.5 to 7.5 with a global mean of 5.792. The overall mean of observed and expected heterozygosity were 0.489 and 0.787 respectively. Within population, inbreeding estimate (F IS = 0.381) indicated shortfall of heterozygosity in the population. Microsatellite analysis revealed less genetic diversity in both the species. The Analysis of Molecular Variance (AMOVA) showed 23% of total variation between both the species. Applications/Improvements: With the actual genetic diversity and the population structure of these two whelk genetic groups evaluated, it was possible to clarify their importance as well as to propose some management strategies to avoid further loss of genetic diversity in these whelk species.