Molecular identification of hammerhead shark trunks from the southern Gulf of California using multiplex PCR

Abstract
The demand for shark fins in Asiatic markets has resulted in excessive increases in shark catches, even for species that may be under protection or subject to management. As such, it has been necessary to develop and promote monitoring efforts for exploited species and taxonomic groups in order to improve fishing management strategies for elasmobranchs. Identifying species from landings is one of many fishing management problems because landed organisms have usually already been processed and are therefore incomplete, which makes identification problematic, impedes the generation of proper species records, and leads to poor fishery assessments. Tools that can correctly identify species, such as various molecular techniques, have become essential for accurate fishery assessments. In this study, 30 hammerhead trunks from artisanal fisheries from the southern portion of the Gulf of California were identified using multiplex PCR (17 Sphyrna lewini and 13 Sphyrna zygaena). The total fee to identify each trunk with this technique was ~ $3.80 and the procedure required 2 to 5 days. When compared with other widely-used methods, such as PCR-RFLP or barcoding, multiplex PCR is fast, efficient, low-cost, and easy to implement in a laboratory.