Backyard Aquaponics
A place to discuss aquaponics

Hey guys,
A few weeks ago I noticed these small, round worms (little under a cm) swimming around my tilapia tank. They are extremely thin and move their body rapidly in a flagellum motion to swim. My first instinct was to assume these guys were nematodes, and since none of my fish seem to be dying or affected, I figured I'd let them stay in the tank. Now, they have proliferated and found a way into the NFT i'm cycling. Another concern is i've been told nematodes are usually white. These guys are orange, which is potentially a byproduct of them eating the fish food which has an orangish brown color. The following link is a picture. http://i57.tinypic.com/2unvgps.jpg

Can someone please help me identify this mysterious worm?

Much thanks!

Most likely midge larvae.. Do a search online for midge larvae and see if that's them... Bit hard to tell for sure from your photo..

I get these in small ponds, there seems to be two types i have witnessed, i can not help you with what it is though.

one type is more red than orange, they make tubes of dirt/fecal matter on the bottom and sit in there, sometimes sticking out and waving around - i gather to collect food. These are usually very prolific, but may not be so much in a clean bottom fish tank.

the other type im not so sure about, i just see the odd one or two swimming around, in the manner you mentioned, they are less red than the other type.

I have not witnessed either of these worms interacting with fish or plants.