The "Alligator Gar" is not a native of Thailand, but comes from Southern USA.
It's pretty common in the aquarium trade though, but as it soon outgrows most home aquariums people release them into their local ponds!
If they can find a mate and spawn, they can run havoc on local fish species, and make them endangered or in the extreme even extinct!
There are cases opposite to this one where South-East Asian "Snake-Heads", has been released in southern US waters and multiplied, creating lot a of problems for fish and people!
Plahgat