Weak population structure of the Spot-tail shark Carcharhinus sorrah and the Blacktip shark C. limbatus along the coasts of the Arabian Peninsula, Pakistan and South Africa

The increase in demand for shark meat and fins has placed shark populations worldwide under high fishing pressure. In the Arabian region, the Spot-tail shark Carcharhinus sorrah and the Blacktip shark Carcharhinus limbatus are among the most exploited species. In this study we investigated the population genetic structure of C. sorrah (n= 327) along the coasts of the Arabian Peninsula and of C. limbatus (n= 525) along the Arabian coasts, Pakistan and KwaZulu-Natal, South Africa using microsatellite markers (15 and 11 loci respectively). Our findings support weak population structure in both species. Carcharhinus sorrah exhibited a fine structure, subdividing the area into three groups. The first group comprises all samples from Bahrain, the second from the UAE and Yemen and the third from Oman. Similarly, C. limbatus exhibited population subdivision into three groups. The first group, comprising samples from Bahrain and Kuwait, was highly differentiated from the second and third group,...