Aquatic forest insect identification
This is a caddisfly larvae (Trichoptera). They live in streams and other water that are rich in oxygen. 
They protect themselves by building there own 'house', with whatever is available, e.g. plant or wood fragments, gravel or even snail shells (see picture below)


Picture from Dutch wiki

https://en.wikipedia.org/wiki/Caddisfly



Id to species level probably requires microscopic work.