Pond Jellyfish

[Turkeyfether]

I have a very nice spring fed pond in upper Pa. full of fish. Just noticed jellyfish the size of a nickel. Any clue what these are & how to get rid of them so they don't create havoc to the balance of things in there?
I also just learned today that if you have a pond,get rid of the tadpoles & the eggs in the spring.They destroy the minnows.

[HiouchiDump]

This is almost certainly Craspedacusta sowerbii, not truly a jellyfish, but the medusa of a fresh water Hydrozoan.

Hydrozoans are relatives of jellyfish, which are Scyphozoans. You may be familiar with the hydra, which is another Hydrozoan.

Hydrozoans have a complex life cycle, which often includes both a polyp form that is physically attached to something (the bottom, rocks, plants, etc) and a medusa form, which is free floating. The polyp form generally reproduces asexually, but may also split into a medusa. The medusa may reproduce sexually or not at all.

So, it seems you have had a "bloom" of medusae.

I wouldn't worry to much about these upsetting the balance. Medusae are composed almost entirely of water, so they won't create much waste when they die. They prey on very small insects and microbes, so they are no threat to fish. If you really want to get rid of them, you could just scoop them out with a fine net.

I'd take the time to enjoy them, as you don't see these things every day. I've always wanted to find some, but I've been limited to books so far.

[moonwolf]

That is very interesting.

My pond one day had an almost instantaneous 'flush' of snails. The day before, I didn't notice any on the bottom, and when they 'hatched' (they must have....all at the same time) I counted something approximately over a hundred per a square foot. That is Very many by any circumstance. Many died off about a week or two later, but the bottom still has a good number of visible snails. There were a lot of minnows that winter killed this spring, and a lot more frogs are in there that weren't last year. Interesting how pond life changes to 'rebalance' itself.

[pygmywombat]

Wouldn't destroying the frog's also be screwing with the pond's natural balance? We have tons of frogs and tadpoles every year and a healthy population of minnows. Sometimes more or less of each, they always balance out.

[Cyngbaeld]

Frogs are a sign that the water is pure, according to the old folks. Why do you need minnows?

[Turkeyfether]

Thank you all for your input. I don't like to kill wildlife unless I want to EAT IT or if it's destroying my farm/pond supply. Flies are a pain in the butt.I kill them by the hundreds.
Why do I want minnows?? Future fish.Also,food for bigger fish.I don't eat frogs.
OK,so,I'll leave these Jellies alone to enjoy life!(smile)

[Turkeyfether]

Hiouchidump~~ That is pretty amazing information you gave there. How did you learn all this? I'm impressed!

[Hovey Hollow]

As tadpoles frogs are generally vegetarian, and as adults, eat tons of flies. I know larger frogs will eat fish small enough to fit in their mouths that they can catch, but they shouldn't make too much of an impact if the pond is big enough. Frogs typically stick around the edges.


Forgot to add that the fish WILL feed heavily on the tadpoles. Therefore, maintaining a balance in your pond. I would leave all of the creatures there to maintain their own balance.

[HiouchiDump]

Originally Posted by Turkeyfether

Hiouchidump~~ That is pretty amazing information you gave there. How did you learn all this? I'm impressed!

Ha! All I do is remember which books I read things in and pull them off the shelves when I need the info again.

I'm a biology geek - particularly invertebrates. Show me something without a spine and there's a pretty good chance I'll remember some random, obscure information about it. (Politicians not included.)

[chas]

Originally Posted by HiouchiDump

Ha! All I do is remember which books I read things in and pull them off the shelves when I need the info again.

I'm a biology geek - particularly invertebrates. Show me something without a spine and there's a pretty good chance I'll remember some random, obscure information about it. (Politicians not included.)

What do ya know about my brother-in-law ?

[Lararose]

Originally Posted by chas

What do ya know about my brother-in-law ?

Laughing really hard....