The Thai Fisheries Department has succeeded in artificially breeding short mackerel, known locally as “Pla Tu”, a favourite edible fish among Thai people. Hormone-induced spawning was used, with a high survival rate of the fry, according to Chalermchai Suwannarak, director-general of the department.
He said that they have been researching ways to conserve short mackerel in the wild and to increase its numbers in nature, to prevent depletion through overfishing.
Breeding the short mackerel in captivity is a considerable challenge, because the fish is fragile and dies easily after being moved from the sea, he said, adding that researchers at the Fisheries Department have spent years studying the environment of the fish, its spawning season and its food, among other things, in order to replicate the conditions in the spawning tanks.
Chalermchai said that the Phetchaburi Coastal Aquaculture Research and Development Centre had conducted hormone-induced spawning in tanks, with fish caught in the seas off Phetchaburi Province.
Fish of both sexes are placed together in the spawning tank following hormone injections. The female ovulates when she is physiologically ready. The male stimulates the female to release the roe and then fertilises them.
The results were satisfactory, with between 2,250-20,000 fry being bred on six occasions, or a success rate of between 7.94% and 61.54%. The fry are currently being raised in tanks at the research centre in Phetchaburi Province.
Chalermchai said that this was the first time in the world that short mackerel have spawned in captivity, adding that the fish will be released into the sea once they are mature enough to survive.
To conserve the fish, he urged consumers to avoid buying or eating the female of the species if it is carrying roe.