unknown shrimp and slug?

[johnd185]

first off i was itching to go check out my new tonight(lights off)
when i turned the light on i saw about ten shrimp that look like mantis's(or at least the heads)there tails are curled in and they were in little caves in the lr(they did not make the caves natural forming)when they retreated i noticed they fliped or rolled backwards into there cave
too small to take a pic
the largest one is about 2 centimeters others r smaller
the coloring is red-ish with a black or at least dark line down the back
i have red and green striped mushrooms and yellow polyps
now the snails have no shells
Help

 

[johnd185]

heres a pic i found on the internet
its on the tube curled up just like i saw them

 

[ophiura]

Those are gammarid amphipods which are generally beneficial. No worries at all.
Snails don't lose their shells...but there are hitch hiker snails that don't appear to have shells (called Stomatella)

 

[cranberry]

Here's a pic of one in my tank that I removed fro easy viewing....

 

[mr.clownfish]

its cute

 

[johnd185]

ok thanks

if its peacful im peaceful