Is Lutjanus argentimaculatus genetically connected along the Arabian Sea and Bay of Bengal? A study using microsatellite markers br

The mangrove red snapper, Lutjanus argentimaculatus, is a marine fish of key economic and cultural importance in the Indo-Pacific region. It is now considered much more of an important aquaculture species than capture fisheries. The present study aimed to reveal the genetic structure of this candidate species from the Arabian Sea and Bay of Bengal using microsatellite markers. Twelve microsatellite markers used for genetic stock characterization and 384 samples collected from six different locations were used for the study. Genetic characterization using microsatellite markers suggested a single unit stock of red snapper in the sampling region with sufficient gene flow between populations to restrict the genetic structuring. Genetic differentiation co-efficient analysis suggested lack of structuring between populations. However, Bayesian cluster analysis performed in STRUCTURE revealed some evidence of sub-structuring between the Arabian Sea and Bay of Bengal populations. Hierarchical AMOVA analysis, Principal Coordinate Analysis (PCoA) and isolation by distance analysis offered some support to the above findings. The inability of microsatellites to detect population differentiation in this instance suggests the need for more powerful markers, like SNPs, to reveal the sub-structuring before appropriate management practices can be developed for the mangrove red snapper in Indian waters.