White hydra (Hydra vulgaris) in the aquarium: Today we come to speak of animals that are very common in our aquarium, but are usually not intended. So can they freshwater polyps harmful to animals and in our case for them ornamental fish and also for that plants be. Not all of these microorganisms are bad for an aquarium, but there are also species that are not really popular. What anyway Freshwater Polyps Hydras are and what causes they have you can find out here. We also tell you how to get rid of them.
What are the freshwater polyps Hydras anyway?
First you have to go back a bit, because there are four different types of hydras, although only one type causes problems in our aquarium. The White Hydra (Hydra vulgaris) is a small rod-shaped animal that has tentacles on the head area (10 pieces). Next to the white hydra there are also those green hydra Chlorohydra viridis. However, this is rather harmless in the aquarium, but it can still occur. With these, she can hold on to anywhere. She usually does this on smooth surfaces such as the aquarium panes or on furnishings. In addition, she can also hold on to the aquatic plants very well. At the beginning, the animals are quite small and usually difficult to recognize. If they are fed appropriately, however, Hydras can grow up to 3 cm or even slightly larger (of course they are still quite thin and only long in a kind of stalk shape). However, since they are very small in the aquarium, you usually see them quite late, when they have already spread widely. This also makes it difficult to spot the pests in time.[the_ad id="1019″]
The Hydras belong to the tribe of cnidarians (Cnidaria) which causes further problems. You own one nettle capsule. This contains a paralyzing poison which they can deliver to their victims within milliseconds (ms). Thus, these are quickly stunned and the polyps can then eat them. On the menu are many feed animals, which also occur in a tank with young fish. This can be Artemia, larvae, amphipods or even plankton. This alone would not be a problem if there weren't other animals on their menu.
What is the danger of freshwater polyps and hydras
Many nano aquarists and shrimp lovers know these animals very well, because they are quite common there. Of course, they also occur in normal aquariums, but there they usually have predators such as certain ornamental fish (labyrinths and viviparous toothcarps). They are happy about this live food. In a shrimp tank, they don't have these predators. Even worse. they even have food there, because freshwater polyps and hydras also like to eat small ones Young shrimp and shrimp larvae. Exactly what no breeder can use. This can also become a problem in breeding tanks for fish and spawn.
So the freshwater polyps and hydras can multiply quickly and become a nuisance. That's why you should get rid of the animals as soon as possible. But before we get to how to get rid of them, we need to consider how it can happen in the first place.
What causes freshwater polyps to form Hydras
Mostly the hydras are brought in. Be it from Aquatic plants, which you buy in a specialist shop (that's why we always recommend watering them, but unfortunately this is no guarantee either), or you drag them in with other objects or ornamental fish. These pests can also be introduced into live food or mosquito larvae. So you can never completely rule out this risk. If you have them then you have to think about measures to get rid of them.
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How do you get rid of hydras polyps? Fight hydras in the aquarium
It's good that there are different ways to do this. Basically, you can also kill and remove the hydras mechanically, but this usually turns out to be quite difficult, because the animals can still be quite small. Nevertheless, these can be scratched off quite quickly, especially on windows. The deployment of predators is also quite difficult, especially in the nano tank.
Basically, you could also let them dry out, but that would mean having to rearrange your aquarium. Also a possibility which is rather difficult to carry out.
Again and again one finds that an oversupply of food is to blame for the reproduction. That's why it's also a matter of fasting for a few days, provided the stock allows this.
If you have the opportunity to heat the tank to over 40 degrees, this also seems to kill the hydras. Of course, it must be possible to get the stocking out of the tank. In the case of shrimp tanks and breeding facilities, this is usually not feasible.
Probably the best way to get rid of the hydras quickly is to use table salt. Hydras can also be combated with a small amount, we recommend a maximum of 5 grams per liter of aquarium water. However, it is also important to know exactly what you are doing here, because not all shrimp or fish tolerate such an increase in salt in the aquarium.
So let's summarize the possibilities again:
- scrape hydras
- Allow hydras to dry out
- Natural predators such as honey gouramis and others labyrinth fish aber auch platy and swordtails from the group of livebearers.
- Stop feeding some days
- Increase aquarium water temperature to 40 degrees or more.
- salt method
Of course there are also certain chemical agents that can fight the hydras, but this should always be the last resort. The natural methods should be tried first. In most cases these lead to success and you get rid of the hydras.
Finally, a video where you can see the microanimals greatly enlarged: