Strange Critters in My Tank

[FoundMoney]

I was doing a water change yesterday and a bit of a vacuum of the gravel. When I went to dump out the water in the sink I saw a little creature swimming around. I'd say it was about an inch long, and it was mostly tail. The tail took up about 2/3 of the body mass. The rest of the animal had six legs (I think) and a round bulbous head. The color was a light brown, but the body was almost translucent. The way it was swimming when I first saw it, I thought was some kind of fry. But after taking it out of the water it could crawl on its legs, although it seemed much more content in the water. My guess is that it was some kind of fly larva, as the head looked something like a fly.

Before dumping out the rest of the water, I examined the last quart or so of water in the bucket for more creatures. Sure enough I found two other animals. These were much smaller and looked at first like brine shrimp. However, this being a fresh water aquarium I highly doubt that. After further consideration, they most closely resembled mosquito larvae. I'm wondering how fly and mosquito larvae got in the tank in the first place?

Should I be concerned about these "nymphs" floating around in my fishtank? Is this something common in a tank that are usually eaten by fish? I guess the worst thing that could happen is that flies and mosquitos start coming out of the tank, but does the presence of insect larvae indicate some other kind of problem with the tank? What, if anything, should I do?

 

[phil]

Hi Foundmoney

I`ve found a lot of little flies in my tank (mostly on the lights) and I`ve no idea how they got there - I am assuming that when they die they fall in the water and give a little more protein to my fish - I can`t tell you what the other critter was but it does sound like some knind of nymph.

Phil

 

[Squirrelbuddies]

I think they must be sea monkeys!! Does anyone remember those from the 70's?

But seriously--- I did a quick search and found this link:

http/www.uta.edu/biology/gough/courses/w...vertebrates.pdf

It's not specific to aquariums - but describes different types of larvae. Maybe you can find your mystery critter here.

 

[smithrc]

sounds like a damsel fly larve.

 

[FoundMoney]

It definitely looked like a damsel fly larva. According to the linked article, the presence of insects indicates good water quality, although the damsel fly can tolerate less than perfect conditions.

So how does a damsel fly larva get in my tank (or sea monkeys for that matter)? Is it something to be concerned about?

 

[yvez9]

have you recently added anything to the tank recently?

 

[FoundMoney]

Some Vallisneria about two weeks ago. I suppose insects could have come in on that.

 

[evilbunny]

aren't sea monkeys brine shrimp ? just breed bigger ?