I found several of these dipping the same pond in Suffolk over the last few weeks. Ranging from about 5-10mm in length and about 1-2mm in diameter with a transprant body, the mosyt noticable feature is what looks like a central black line down about 2/3 the length of the body that is periodically extruded from the body and moved around, rather like a lashing tail, possibly in search of food.
Could this be a proboscis worm - Prostoma sp? The major diference form the descriptions I've read are that they are not described as transparent, but redish-brown to pink.
Are there other species that have this apparent eversible probiscis that it could be?
The attached very brief video clip shows the "proboscis" in action.
The photo is about x2 magnification. I think it may have captured a food item - the dark linear object across the end of the worm - and the "proboscis" apperas to be slightly extended as there is a small area at its internal end which looks to form part of the body cavity in which it is located when not extended.
Hi, Looks to me like a chironomid midge larva (which you referred to as the dark linear object) in one of its casings (which you referred to as the transparet body). This becomes quite clear in your 1 second video, which shows the chironomid larva sticking part of its body out of its tubular casing.