Investigation urged over suspected mutation of alien fish in Samut Prakan

A shrimp farmer in Samut Prakan province has called on the Fisheries Department to investigate possible mutation of the alien fish species, blackchin tilapia, that is currently spreading in the local waters and aquaculture areas of several provinces.

Originally found in Africa, blackchin tilapia breed rapidly and prey on small fish and fish eggs, causing damage to fish farmers, as well as having knock-on effects on other industries. The fish can live in fresh, sea, and brackish waters.

Adisorn Chansuksawas, owner of a shrimp farm in Bang Bo district, alerted the media on Wednesday after catching a large number of tilapia in his shrimp ponds. He pointed out that the caught fish, though they clearly looked like the Nile tilapia, also had characteristics of the blackchin tilapia.

He demonstrated to reporters by casting a fishnet in a pond and bringing up a number of fish. Among them were three tilapias, two small and one large.

Adisorn said the large one and a small one are clearly Nile tilapias, as they have round bodies, small heads with protruding mouths, and no black spots on their chins.

Another small tilapia, however, has all the characteristics of Nile tilapia, except it has black spots on the chin.

“This one could be a mutant,” he said, pointing at the bottom fish in the picture. “It has a black chin, but does not have a slim body and a large head like typical blackchin tilapia.”

Adisorn urged the Fisheries Department to investigate the possible mutation, which could be a result of cross-breeding in nature, as well as its impact on the ecological system.

Nile tilapia (Oreochromis niloticus) is a species of tilapia brought to Thailand in 1965 by Japan’s then-crown prince and later emperor Akihito in 1965 as a gift to King Rama IX.

The King named it “Pla Nil” after the Nile River where the fish originated and donated 10,000 tilapia fish he had bred at Bangkok’s Chitralada Palace to the Fisheries Department for breeding and distribution to farmers.

Pla Nil has quickly become popular in Thailand due to its easy-to-raise nature and delicious meat.