Genetic Diversity of Three Spotted Seahorse, Hippocampus trimaculatus (Leach, 1814 ) in India Using Four Microsatellite Loci

Seahorse populations are declining year by year not only in India but also throughout the world, because of over-fishing and increasing demand in Chinese market. The three spotted seahorse, Hippocampus trimaculatus is one of the dominant species and distributed all along the Indian coast. To study the genetic structure is very essential to conserve these species effectively. Hippocampus trimaculatus samples (n = 60/population) were collected from Mullimunai in Palk Bay, Tuticorin in Gulf of Mannar and Vizhinjam in south Malabar in India as by-catch in small trawlnets. Microsatellites are being widely applied in animal genome mapping and phylogenetic analysis because of their co-dominant inheritance and high degree of polymorphism. The molecular polymorphism of microsatellite DNA has proved to be a potent tool in the analysis of several aspects of population genetics. In the present study, four microsatellite primers were used to investigate the genetic difference and structure of three selected populations of H. trimaculatus. The result showed the overall FST value (0.0989) of the microsatellite loci between Mullimunai and Vizhinjam was significantly different. The genetic distance between Mullimunai and Tuticorin was 0.183; between Tuticorin and Vizhinjam was 0.461; and Mullimunai and Vizhinjam was 0.837. There was no statistical evidence of recent severe bottlenecks in any of the three populations. Continuous monitoring of microsatellite variations within the populations of all the three locations was suggested to determine whether genetic variation within the populations is stabilized between year classes.