Latin name: Hydra Other names: Pathogen:
Open wounds on the body.
Hydra is a predator which is introduced into the aquarium with feed and other water bodies (plants, snags, etc) taken from ponds. It is 2-3 mm in length. Hydra has a circle of tentacles around their body opening. It attaches itself to an object in the water with the so-called ‘sole’. It moves by means of tentacles. Hydra loves light. It is a voracious predator that feeds on fry. Hydra waits for its prey while attached to an object in the water. With tentacles spread apart, it does looping movements while searching for a prey. Hydra catches the prey by means of the tentacles and then paralyses it by special cells called nematocysts. During the spawning period it can eliminate all fry.
How to cure:
Once Hydra is identified, dim the light so that only one illuminated spot is left (this can be achieved by pressing a glass to the side of the tank). Hydras that will accumulate in this place should be disposed of. Young Gourami fish also help to eradicate hydra.
It is necessary to carefully check all feed before introducing it into the aquarium.