Molecular analyses reveal a lack of genetic structuring in the scalloped hammerhead shark, Sphyrna lewini (Griffith & Smith, 1834) along the Indian coast

The scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), is an important species along the Indian coast both in the Arabian Sea and Bay of Bengal. As per the IUCN Red List Assessment, the scalloped hammerhead shark is categorized as “globally endangered.”We investigated the intra-specific genetic diversity and population genetic structure of S. lewini along the Indian coast (Arabian Sea and Bay of Bengal) by analyzing mitochondrial cytochrome C oxidase 1 and control region sequences, respectively. Furthermore, comparisons of the sequence data generated from the present study with the sequences of S. lewini retrieved from GenBank revealed the presence of three (3) haplogroups corresponding to Indian/Indo-Pacific, Atlantic, and Pacific regions. A lack of genetic differentiation within the Indian coast and significant differentiation between ocean basins (FST; 0.80; p < 0.001) indicated female philopatry as mitochondrial DNA is maternally inherited. Hammerhead sharks are inherently vulnerable to fishing practices directly and indirectly (as bycatch) due to their evolutionary distinct features like cephalofoil. Specialized species-specific management measures are urgently needed to protect these precious resources of the oceans