Pond 'worm' identification.
I have some 'worms' I've never seen before in one of the ponds in my backyard, and was hoping you could identify them. [There are actually two kinds that I have never before seen. However, a fish pond identification page helped me identify the first ones as bloodworms.]
The other 'worms' are the real reason I'm writing.
Pictures of one of them can be seen here:
They are around 2" total length (if I pick up some of the larger ones by the tail and hang them, their tail itself is 2" and the body an additional ~1"). [In that first picture, the creature still all curled up from having been pulled from the water. They don't like to be out of the water.]
Their tails stop getting 'coated' near the tip. When moving on a surface, or attempting to 'swim', they undulate their bodies like an elephant seal or a caterpillar.
They have (on their translucent bodies) rows of stumpy legs 'underneath' (so they do have a distinct top and bottom), like a caterpillar or sea-cucumber. (I didn't count them but I believe it was around 4 or 5 pairs.)
They exhibit two interesting behaviors: 1) The majority of them have the tip of their tail just breaking the surface of the water, and they hang from this tip (held up by surface tension) straight down.
2) They seem to be able to control their buoyancy. When hanging in this state, their body will occasionally and suddenly float upwards, only to bob back down again. It may be that they are pulling themselves up by bending sideways with their tail, but my instincts from the way they were moving made me believe that it was the body floating/sinking unrelated to tail leverage.
These 'worms', like the bloodworms, are in a rather oxygen-poor pond, and I believe all the fish are not in this section (so they're not being preyed upon). Looking today, I see that there are some mosquito larvae in the pond also, if that helps describe the conditions.
Thanks for your excellent pictures (link below), not everybody takes the time to shoot a portrait of a Rat-tailed Maggot! Click on the link to our field guide (at top right of this page) and read all about these common creatures.