Insect larvae??

Insect larvae??

Observation - Insect larvae?? - UK and Ireland. Description: I thought these were leeches until I had a good look. Then maybe some sort of fly larvae. Now I'm completely unsure... They live in my garden pond and I find them in the pond filter... they are typically about 25mm when stretching out with that tube at th

I thought these were leeches until I had a good look. Then maybe some sort of fly larvae. Now I'm completely unsure... They live in my garden pond and I find them in the pond filter... they are typically about 25mm when stretching out with that tube at the front and 5mm when hunched up...