hermit crab or shrimp or um... thing question

[AlienAnchovies]

over the weekend my friend went to corpus christi texas and collected tons of hermit crab shrimp things, i wanted to know if it was safe to keep them and if any one knows what they are.
they look like hermit crabs but i saw one change into an old turbo snail shell and it had a body that reminded me of a shrimp

 

[odoprelude]

hermit crabs do have a body kind of like a shrimp, their appendages have evolved so that they can hold tight to there shells. They really do look weird when changing up shells... hth