What is this disturbing large larvae in the pond outside?

September 20, 2009 10:34 PM

What is this strange larvae in the puddle outside my dorm?

So there's this large puddle outside my dorm by the bike racks that's usually there the majority of the semester, due to the amount of rain we get. Think small vernal pool. Usually it's home to mosquito larvae, mass concentrations of toad tadpoles (excellent for pranking dormmates with fishtanks--last year we convinced one guy his guppies had had ugly babies, and he didn't figure it out until they spouted legs) and waterbugs. However, this year there's something strange living in there that I don't recognize.

From above, they look very much like minnows, a good inch long and that grey color, which is what made me notice them, as I was trying to figure out how fish would get into a temporary pond. However, on close inspection they are typical larvae shape, no fins, and instead of a head they have sort of a weird short tentacle-y mouthpart, almost cthulu-esque. A bit freaky, really, which is why I didn't pull one out for a picture or closer inspection. They swim sort of like minnows would, though, and not with the jerky movements that mosquito larvae have.

So, any ideas what the hell has moved in by the dorm? Some sort of leech thing? Strange water-beetle larvae? Elder-god grandchildren? Swine flu? This is central Texas, and having grown up a tomboy, I'm familiar with most pond-life, but this one is a new one to me. Any help is appreciated, googling variants of "puddle" and "larvae" bring up only endless pages on mosquitoes.

posted by internet!Hannah to science & nature (9 comments total)

could they be nymphs?
posted by buggzzee23 at 10:44 PM on September 20

No, there weren't any obvious legs, and they were definitely swimming around (they very much look like small fish at a distance), not clinging to any plants or at the bottom of the puddle.
posted by internet!Hannah at 10:53 PM on September 20

Are they cranefly larvae or something similar? if it looks at least vaguely similar, I would bet that it's some Dipteran larva.
posted by pemberkins at 4:08 AM on September 21

Oh, except I'm not sure that they would be swimming around like fish. Hm.
posted by pemberkins at 4:09 AM on September 21

Chaoborus?
posted by kuujjuarapik at 5:20 AM on September 21

I'm going to throw out leeches. It kind of looks like what you described.
posted by Mastercheddaar at 7:13 AM on September 21

Perhaps a rat-tailed maggot?
posted by tomierna at 12:20 PM on September 21

None of the above choices seem quite right. The things are getting bigger, and definitely eating the tadpoles. I am thinking they might be some sort of shrimp...thing...now that they are a bit bigger, as it looks like they have some small legs up at the front of their bodies. Still can't find anyting online that resembles them, though.
posted by internet!Hannah at 8:57 PM on September 22

Diving beetle larva will eat tadpoles.
posted by kuujjuarapik at 9:16 AM on September 23