Creature ID?

[Morgan]

So my tank's alive with small lifeforms, lots of copepods and nematodes and who knows what else. I noticed something I couldn't identify and I'm hoping someone knows what it is.

 

To the naked eye it looks sort of like a small green beetle or insect. It's about 1mm long, and both swims through the water column and settles on the glass/plants. Swimming is fast and smooth, not like a copepod, actually reminds me a bit of watching a blowfly hum around a room before settling.

 

Anyone seen this or knows what it is?

 

 

[petfish]

only a guess, Daphnia (water flea)

[kizshrimp]

Probably a seed shrimp, an Isopod. Swimming habit sounds right; daphnia don't swim so deliberately and never settle on surfaces. 

[2OFUS]

That's definately a seed shrimp

Harmful

And it also is a sign of a good balance in your water column

[Morgan]

Thanks guys. I knew it wasn't a daphnia, I kept a daphnia culture years ago and their popping movements are pretty distinctive.

 

Harmful how, 2OFUS? To shrimplets? I can try to suck them out them with a pipette, there's only a couple in there atm.

[Shrimpy Daddy]

Seed shrimp a.k.a Ostracod: http://en.wikipedia.org/wiki/Ostracod

 

Due to their hard shell, they are dislike by predator. Hence, if you have a lot of uneaten food in the substrate, their population will bloom exponentially.

 

They are pretty harmless. In actual fact, you are able to use their population and activity to gauge the quality of your water. If your water quality is bad, they will start dying even before your shrimp.

[kizshrimp]

Must have been a bit early when I posted. Isopod... dumbass. Thanks shrimpy daddy for posting the correct name for these. 

[jayc]

Harmful how, 2OFUS? To shrimplets? I can try to suck them out them with a pipette, there's only a couple in there atm.

 

I'm pretty sure 2OFUS meant harmless, instead of harmful.

[2OFUS]

That's rite :)I was suppose to say harmless

[Morgan]

Phew, thanks for that. Looks like I've got an early warning system then. They're rather cute and now that i know they aren't going to get bigger and eat anything I can enjoy them.

[Shrimpy Daddy]

Phew, thanks for that. Looks like I've got an early warning system then. They're rather cute and now that i know they aren't going to get bigger and eat anything I can enjoy them.

 

If you have plant (not moss), they will eat it. Frequently, you will find tiny holes appearing at the bottom leaves. When their colony grew (it can reaches hundreds and thousands easily), they can get pretty disgusting when they swam (When you turn off and off the filter/pump), they will swam to the surface of the substrate to consume the plankton.

[Shrimpy Daddy]

Forgot to mention this. If their colony gets big and food are scarce, they will eat pond snail or any snail that has very tender skin. 

[Morgan]

A mixed blessing then. I wouldn't mind them eating pond snails, I've had a couple of small ones show up so far. I don't want them eating my plants though, like little water-aphids. I'll keep an eye on the plants and see if they start getting eaten.

[Shrimpy Daddy]

They don't eat plant like water aphid per se. They will only eat the weak and/ or old leaves. They are scavenger like shrimp too.