The Indian Mackerel, which fish lovers across the country relish, shares the same genetic profile except those caught from Andaman waters, it has been found.
The fishes collected from Andaman waters were found to be genetically distinctive from those caught from the Indian mainland. However, there was little genetic differentiation between the fish caught from across India. These were some of the results of one of the biggest studies on an Indian fish species for genetic stock identification.
The genetic profiling was carried out by researchers of the Central Marine Fish Research Institute (CMFRI), Kochi and the National Bureau of Fish Genetic Research (NBFGR), Kochi regional centre.
The study formed part of the Bay of Bengal Large Marine Ecosystem (BOBLME) Project, supported by the Food and Agriculture Organization. Researchers from India, Bangladesh, Indonesia, Malaysia, Maldives, Myanmar, Sri Lanka, and Thailand are working together in the project.
Besides other things, the NBFGR had developed fourteen microsatellite loci. The genetic analysis was carried out on these samples using the microsatellite primers.
The Indian Mackerel — Rastrelliger kanagurta — is an important food fish commonly consumed in South and Southeast Asian countries. Though the trans-boundary species is harvested by different nations, its population genetics is relatively unknown to the scientific world.
Of the 3,100 samples collected from across the eight countries, nearly 800 were from India. The Indian samples were collected from Mumbai, Mangalore, Calicut, Kochi, Tuticorin, Nagapatnam, Kakinada, Paradeep and Port Blair.
Molecular identity of all three species of mackerels — Rastrelliger kanagurta, Rastrelliger faugni and Rastrelliger brachysoma — distributed along Indian waters were also evaluated using DNA barcodes.
The preliminary data analysis revealed that the population of the species was in random mating; overall, a low genetic differentiation existed among the mackerel populations distributed along the Indian mainland.
The assessment of genetic variability of a fish species is important for the management of its wild genetic resources. Most species are composed of populations, also called genetic stocks, between which limited gene flow occurs. These populations maintain their genetic makeup or characteristics distinct from other populations of the same species due to genetic variation within the species, explained researchers.
The genetic profiling of the species is essential to assess the stock, evolve fisheries management methods including the preservation of genetic diversity and sustainability of the regional fisheries, say scientists.
The fish is commonly found in warm shallow waters along the coasts of the Indian and West Pacific oceans, and their surrounding seas. It contributed an average 8.8 per cent of the total marine fish production in the country. Its average annual catch was estimated to be 0.27 million tonnes, according to available data.
