Hydra?

[Pineapple House]

I found a few Hydra's in my tank (actually, hundreds of them), and wondering if they were any threat to my tank? What do they eat? Thanks

PH =)

[RTR]

They eat baby brine shrimp, and other small infusorians, also small fish fry such as many egglayers.

Blue, opaline, and the other color varieties of that gourami eat hydra.

[djlen]

How in the world did you introduce Hydra into your tank? Back in the old days when people would scoop daphnia out of ponds they used to say to watch out for Hydra. Did you recently put something into the tank that would carry them as well?
Len

[RTR]

I've introduced them with plants several times. Which I why I now QT everything. But hydra infestations are a bit like cloudy water, they tend to boom, then the population collapses if they have no suitable food.

[a_free_bird73]

Unless you are breeding fish, I would not worry about it, though they tend to irritate small fish.

If you are really concerned about it, Copper based medications are very effective in killing hydra though I would not take the use of copper in aquariums lightly.

[wetmanNY]

"The hydra ye always have with you." We just don't notice them until they're reenacting The Attack of the Clones (quite literally, in the hydra case). When I remove my male Paradisefish from his plant nusery, the hydra will reappear, I'm sure. They're predators. They don't eat the extra fish flakes: they eat the rotifers that eat the ciliates that eat the extra fish flakes.

RTR I think your hydra population is just so well in balance you don't see them. Like flatworms.

[gnome]

A year ago I had a hydra infestation (presumably from a daphnia culture I had going for a short while). Worst of all, it was in a planted tank, and I didn't want to even stick my hand in the water with the creepy things waving at me. I'd seen one do a cartwheel, so I knew they *could* move from where they were apparently "anchored." I was totally grossed out, but didn't want to hurt my hard-working little snails. Somebody suggested Bausman Gold & Tropical Fish Tonic. On the directions, it tells you exactly how to treat for hydra, but one of the listed ingredients is salt, so I knew that my plants would suffer, to some degree. Well, I REALLY wanted to get the creepies out of my tank, so I went ahead with the treatment. Sure enough, my plants did start to languish, starting with the floating riccia. I think what hurt most was that the directions say to wait six days before deciding to add the extra half-dose. I'd say don't bother waiting that long. Maybe go with the initial dosage (1 tsp/gallon), dissolving it in some water and squirting the solution with a dropper or a turkey baster *directly at* the hydra that you can see (they'll ball up and fall off). Rather than waiting six days, I'd only wait two, check to see if there are still any visible hydra; if there aren't, do a major water change to dilute the salt. If hydra are still present, add the half-dose (again, squirting directly at the persisting hydra) and wait no more than maybe 3 days before doing the water change.

On the other hand, if you don't have any plants in the tank, just follow the directions as written.

My plants eventually bounced back (and I was following the directions), but the hydra were zapped into oblivion. My snails were apparently unharmed, as well. I think I got the tonic from That Fish Place or Drs. Foster and Smith. Cheap and effective. If my tank was large enough, I'd have probably tried the gouramis before resorting to chemicals, though. Good luck!

[RTR]

I doubt that wetman, they should be able to eat the Dwarf Neon Rainbow fry that pop up throughout the system. And the Cherry Barb fry (but I don't know if those are as small as the Rainbows). Imagine how they could feast on Amano babies! But everything is possible.

[Flohrie]

Could someone enlighten me? What is hydra?? :confused:

[wetmanNY]

Freshwater polyps. Same phylum as corals, sea jellies, etc. These are the only-- almost-- Cnidaria to make it into freshwater.

I have some stuff and some links at www.skepticalaquarist.com Invertebrate folder.