amphipod

amfipodi A member of taxonomic order Amphipoda of small, shrimp-like crustaceans.
2003, (w), A Short History of Nearly Everything, BCA, p. 212:

We have managed just once, briefly, to send humans to that depth in a sturdy diving vessel, yet it is home to colonies of amphipods, a type of crustacean similar to shrimp but transparent, which survive without any protection at all.