Strange brown thing in fry grow tank!!!!

[humdedum]

Sorry if this is another thread, but i need help RIGTH NOW! I have a ten-gallon spare tank, cycled and waiting around for an emergency. So last Saturday, i found 22 zebra danio fry from my Narnia tank! (20 long, 6 danios, 1 platy, 2 cory cats). So i moved them to this new emergency tank. They are tiny, 3mm long and as thin as a hair.
So today, i look in from the top to count them (i counted only 19) and then i though i saw like 4 clumped together! LOOKED CLOSER, AND it was a brown....thing????????????? No idea what it is! Imagine a crab. Turn it brown. Make it smaller, 3 or 4 mm across. Then simplify it, to maybe just four little "legs??". *shudder* Please help!!!!!!!!!!!


**UPDATE** I looked again and saw TWO this time. And i was able to catch one. Two long legs on either side, bunch of little ones on its underside. Pic late maybe.

 

[buddha_red]

A pic would be a great help in ID'ing this thing.

 

[humdedum]

pic!!

Here's a pic. Sorry, a little late. Hope it helps.

 

[peaceablegarden]

Wish I could say what it was, I'm sure someone else will be able to identify it. I think I've seen these guys in freshwater ponds and lakes in upstate NY.

 

[gzeiger]

That's a water boatman (likely family Corixidae, of which numerous species look the same; possibly Notonectidae - Wikipedia will tell you how to distinguish them if you care). It's an aquatic insect, and it's probably quite harmless both to you and your fish. Corixidae are herbivorous, living on algae or stem plants in your tank. Notonectidae are predators and may attack your fry. Both can fly and may or may not have come from your other tank. If you want more information, Google knows all now that you have the names.

 

[GhostKnife]

Yea its what some call a water bug. You can see them on streams, rivers, ponds and bay areas here in ohio ... Around lake erie as well. The two long oar looking things are just that ... that is how they scoot along the water kind of like a canoe. Just toss it outside or in trash or something. How it got there is what you want to find out. Is it still warm where you are? windows open?

 

[humdedum]

Okay, i think it's that new hornwort i bought. Here's what happened in order of events:

I found fry.
I bought hornwort and washed it real , then put it in the tank.

One day later....

"AHHH DAD WHAT'S THIS!"

Basically. No, here in Illinois, it's been pretty cold, but we did have a warm spell. The warmest it got was probably 55 last week. or so. The tanks are in the basement, and the basement isn't finished, and the tanks aren't in a fishroom in a basement, much as i'd like to build one later on. ^.^