Assessment of Genetic Variation in COI Gene of Horseshoe Crab (Tachypleus Gigas) Population Along the Coast of the Bay of Bengal in Odisha, India

Abstract

Horseshoe crab (Tachypleus gigas) is an archaic group of marine creature which plays a vital role in the saline ecosystem. Many researchers emphasize and enhance the knowledge about the horseshoe crab's basic biology, morphology, and ecology, whereas very little information is available about its population genetics. We attempted to develop a baseline database about the ecology, phylogeography, and genetic variation among the horseshoe crab population from Odisha, India. We collected 152 samples of horseshoe crab from the coastal area of the Bay of Bengal. The generated Cytochrome C Oxidase Subunit I gene (COI) sequences of T. gigas were compared with the sequences of T. gigas obtained from GenBank. The GenBank sequences were of two populations from South China and Malaysia. A total of 26 unique haplotypes were observed in three populations of T. gigas. Pairwise F-statistic distance (FST) between South China-India was 0.708; Malaysia-India was 0.608, and South China-Malaysia was 0.136. It indicated that the South China population was closely related to the Malaysian population and the Indian population was appeared to be genetically distinct from the other two populations. It signifies the ecological importance of the Indian population. Furthermore, the migrant per generation (Nm) was 0.16, which indicated a low gene flow among T. gigas populations. The haplotype diversity (Hd) and nucleotide diversity (π) were 0.58826 and 0.00476, respectively. This study would help lay future strategy and conservation of horseshoe crab across the Bay of Bengal.

Identification and Morphology of the Two Horseshoe Crab Species, Tachypleus tridentatus (Leah, 1819) and Carcinoscorpius rotundicauda (Latreille, 1802) (Merostomata: Limulidae) from Honda Bay, Palawan, Philippines

“…Pierce et al (2000) showed that the smallersized L. polyphemus from upper Chesapeake Bay, Maryland genetically differed from larger horseshoe crabs from Delaware Bay, New Jersey. With regard to the Asian horseshoe crabs, molecular analysis of the mtDNA gene (COI) showed genetic variation and discrete populations of T. gigas collected in India, South China, and Malaysia (Tudu et al 2021). Similarly, mitochondrial marker sequences of COI confirmed a clear separation of C. rotundicauda population on the east coast from those of the west coast of Peninsular Malaysia (Fairuz-Fosi et al 2021).…”