Three Spot Gouramis
The three-spot or blue gourami, Trichogaster trichopterus, may be a popularly misnamed species. Actually,the species has only two spots, large and dark, on its body. The third spot is generally considered to be the eye.
The three-spot is not as peaceful as the other gouramis and has been known to attack smaller fish. Though it also builds a bubble-nest, it really does not need it since its eggs are lighter than water and float. The young, too, when they hatch out of the eggs are very light and float on the surface of the water. The three- spot and the blue gourami are identical except that the blue gourami has a hazy coat of whitish blue that does not obscure the spots, however.
The blue and three-spot gouramis, as well as the pearl gourami, which we shall mention presently, are well known for their hydra eating. Hydras are tiny pests with tentacles that contain a potent venom. When a small fish comes into contact with their tentacles it is held fast and paralyzed, and then devoured. Hydras also have an appetite for daphnia, which are more their own size. The writer has observed hydras that have had all their tentacles filled with paralyzed daphnia, awaiting a suitable appetite to ingest the unfortunate victims.
As can be understood, therefore, hydras are not welcome guests in the home aquarium. When they have infested the aquarium, about the only economical way to clear them out is to place a few pearl gouramis in the tank and let them stay hungry until they resort to eating hydras. After a time they get to relish these pests, and your hydra problem is solved.
