Planaria and Hydra

[aura5195]

My 10 gallon freshwater tank with one fish in it has Planaria worms and Hydra living in it. They are all very small and I have no idea how long they've been in there for. The fish ignores them, they don't appear to be bad for the tank in any way and I don't mind them but I am concerned that they are there when they didn't used to be.

Does anyone know if their presence is indicative of another problem with the tank I should look into? Should I try to get rid of them?

[Carl]

First, are you sure you have Planaria?
Planaria are not all that common, yet Detritus worms are much more common. Unfortunately the Internet (especially about.com & YA) have perpetuated the myth of confusing these two very different worms with very different aquarium implications.
See:Fish as Pets; Planaria, Detritus Worms

Both Planaria and Hydra need to be transplanted from ponds and this certainly can happen, especially with the addition of live plants.
Both of these can harm weak fish fry (or eggs in the case of Planaria).

In the case of Detritus worms (which are vastly more common), the implication of these on the glass or otherwise not in the gravel (where they are actually beneficial in limited numbers) is a depletion of dissolved oxygen and indicates high amounts of organic decomposition.

Carl

[parker002]

Planaria are flatworms and are fairly easy to identify under a magnifying glass, as they have a distinctive shovel-shaped head.

[aura5195]

They are definitel Planaria, they have the funny shovel-shaped head and I've only seen 2 or 3 at the most at a time. My main concern is that the presence of these worms and the Hydra mean that my water balance may be off or I'm not cleaning the tank enough. What I've read online regarding both is a bit confusing though as one source says the Planaria mean I have dirty gravel but another says that the Hydra only survive in clean, well maintained tanks.

[Carl]

Planaria are not composter as Detritus Worms, so they are not an indicator of dirty gravel.
This is part of the misinformation about Planaria since they are primarily carnivores.

Generally Hydra prefer good water quality as you noted, and both have to be introduced from ponds (or possibly aquariums, although rare) that contain them.
My concern is how they got into your aquarium, not that your aquarium is in poor health.

Did you look at the link I provided?

Carl

[aura5195]

I did look at the link provided and thank you! I agree, it can be hard to find good information sometimes when everyone thinks they know the answer. As to how these little guys got into my aquarium..I have no clue. I've been thinking and thinking and the best I can come up with is I or one of my boys stuck our hand in the tank after messing around in the pond in our backyard.

My tank has been vacant for the last 2 weeks due to the death of my Betta. He appeared to have Pop-eye, was treated and improved but dies about two weeks after we finished the medication. I just placed a new fish in the tank and that is when I noticed the new little guys everywhere.

So I don't know where the Hydra and flatworms have come from, what they've been eating and how long they've been in there.

So if the Planaria and Hydra are carnivores and I don't plan on raising shrimp or fry of any kind, this should be an ok situation? It's just a little alarming to sit and watch my tank and see the little flatworms oozing along(pretty fast too!) like little slugs on the tank walls and the Hydra hanging all over as well as floating around loose.

[danny]

i have this problem too in my tank.and i also thought that they were planarias too.but turns out they were detrittus(read carl's link and considered the water quality of my water) plus a lot of cyclops.their population is alarming at 1st,but put them to good use when i got tired of getting rid of them.i use them now as fry foods and the result is amazing.i still have the problem right now but i don't mind.hehe!free fry food!!

[danny]

btw,are detritus healthy as food?

[Carl]

Dec 14, 2009 22:36:21 GMT -5 aura5195 said:

So if the Planaria and Hydra are carnivores and I don't plan on raising shrimp or fry of any kind, this should be an ok situation? It's just a little alarming to sit and watch my tank and see the little flatworms oozing along(pretty fast too!) like little slugs on the tank walls and the Hydra hanging all over as well as floating around loose.

The answer is yes, they may even die out unless there is an unknown food source for them in your aquarium.

If you are unsure of your tank health after the death of your Betta (sorry BTW), you could sterilize your tank and start over.
I am not saying this is necessary, only that this is an option.
See: Healthy Aquarium; Section 11, Sterilization

Carl

[Carl]

Dec 15, 2009 5:31:48 GMT -5 danny said:

btw,are detritus healthy as food?

Yes, I have seen many fish eat these.

Carl

[babygeige]

I had little wormy things in my 10 gallon a couple of years ago. My male betta Jasper would eat them, lol. Then they disappeared and I haven't seen them since.