A black slug lined in blue-white and edged in orange, gliding over sand with a flat shield over its head and two unequal tails trailing behind.
The shield is the tool the group is named for. It is a smooth wedge used to plow through the top layer of sand without the animal having to lift anything, so the slug can hunt below the surface while moving. There are no tentacles on top - they would be in the way.
What it hunts is worth knowing: flatworms, and small ones almost exclusively. Headshield slugs follow the mucus trail a flatworm leaves, catch up with it, and swallow it whole - one of the few predators of a group that is otherwise very well defended chemically.
It is a simultaneous hermaphrodite like other sea slugs, and it lays a coiled ribbon of eggs in the sand. Five centimeters (2 in), common on shallow sand flats, and usually found by noticing a moving line of blue where nothing should be moving.
- black body with fine blue-white lines and orange margins
- flattened shield over the head, with no visible tentacles
- two unequal tail lobes trailing behind
- length up to 5 cm
