re·mor·a 
(rĭ-môrə, rĕmər-ə)
(rĭ-môrə, rĕmər-ə)n.
Any of several marine fishes of the family Echeneidae, having on the head a sucking disk with which they attach themselves to sharks and other fishes, whales, sea turtles, or the hulls of ships. Also called shark sucker, suckerfish.
[Latin, delay (from the belief that they could slow ships down), from remorārī, to delay : re-, re- + morārī, to delay (from mora, delay).]