Oceanic researchers have prepared the genetic fingerprints of 85 species of shark varieties found in Indian waters.
The DNA fingerprinting of these less-studied species is considered to be a significant achievement in identifying the threatened ones, and evolving management practices for them, according to researchers. The fingerprinting was carried out as a spin-off programme of the research project for the survey and assessment of deep sea species of the Indian Ocean, funded by the Ministry of Earth Sciences.
India is considered the second largest shark-fishing nation. Most varieties are exploited for fin, oil and meat.
The fingerprinting was carried out by the team of researchers from the Central Marine Fisheries Research Institute, Kochi, and the Kochi regional centre of the National Bureau of Fish Genetic Resources, Lucknow.
Shark samples were collected from Gujarat, Tuticorin, Cochin fisheries harbour and Neendakara fishing harbour. The researchers were led by the former head of the Pelagic Fisheries Division of the Institute, N.G.K. Pillai, and A. Gopalakrishnan of the Bureau. Other members of the team were K.K. Bineesh, K.V. Akhilesh, and K.A. Sajeela.
The fingerprinting will help in easy identification of the species from a tissue. Most shark varieties are found at a depth of around 250 metres and less is known about them, said Mr. Pillai.
Scientists have established the presence of 110 shark species in the Indian waters. Though they are harvested regularly, there is hardly any species-wise landing details. The International Union for Conservation of Nature has included some of the country's shark varieties in the Red List of threatened species. However, it also recorded that the data regarding these varieties was insufficient, said Mr. Bineesh.
Kulachal fishermen are known to be specialists in shark fishery. They use hook and line, drift gill nets and operate in the deep waters from Kanyakumari to Gujarat.
One major bottleneck in preparing conservation and management plans is the lack of scientific data on the varieties. There is not enough information regarding the species diversity from the region due to lack of dependable morphomeristic characters, identification keys and taxonomic expertise, said Mr. Bineesh, who presented a paper at the first International Shark Conference held in Australia recently.
The use of molecular markers for species identification is useful when traditional taxonomic methods fail due to insufficient morphological information. Several rare sharks have been rediscovered after more than 50 years of their original description, as part of the fingerprinting programme. Many elasmobranchs, including sharks and rays, new to Indian waters were also discovered and confirmed through genetic study, he said.
The barcode data will be useful in curbing illegal trade of protected species. It can even be used in the identification of species from processed fin and meat samples, he said.
