Genetic Diversity and Structure of the Darkfin hind (<em>Cephalopholis urodeta</em>) in the Spratly Islands, Vietnam

Abstract

The darkfin hind, <em>Cephalopholis urodeta</em>, is a commercially valuable reef fish species inhabiting the ecologically important Spratly Islands. Understanding this species' genetic diversity and population structure is crucial for developing effective conservation strategies, particularly given the increasing pressures on coral reef ecosystems. This study investigated the genetic diversity and population structure of <em>C. urodeta</em> within the Spratly archipelago using mitochondrial COI and Cyt b gene markers. We analyzed 30 individuals for COI and Cyt b, revealing high levels of haplotype diversity (Hd=0.9563±0.0226 for COI; Hd=0.9402±0.0229 for Cyt b). However, despite this high overall diversity, our analyses also revealed significant genetic structuring within the archipelago, suggesting restricted gene flow among some populations. This structuring is likely influenced by the complex oceanographic currents in the region and the spatial distance between reefs, which can limit larval dispersal. These findings highlight the need for spatially explicit conservation and management strategies for <em>C. urodeta</em> in the Spratly Islands. Recognizing the genetic differentiation within the archipelago and implementing management measures tailored to specific zones will be crucial for preserving genetic diversity, maintaining connectivity, and ensuring the long-term sustainability of this important resource.