Alder's Acanthozoon

Acanthozoon alderi is a species of flatworm polyclads belonging to the Pseudocerotidae family.

Description

It has an elongate oval body 8-12 cm long. Body is black with lots of little black bumps (papillae) that are yellow or orange tipped, some with a white base that gives the appearance of larger white spots. Margin is white. Underside is pale-whitish with a white outer margin and a black inner margin. It has a pair of small, pointed, ear-like pseudotentacles made up of simple folded edges of the body.

Distribution

Indo-Pacific: from East Africa to South Japan, Nortn Australia, New Caledonia and Fiji.

Habitat

It is benthic and carnivorous.It can be quite active, especially at night. Like a stealthy spotted mat, it is often seen gliding rapidly, hugging the surface closely, ruffling the body edges as it moves. When it swims it elegantly ruffling its body edges to 'fly' or dance through the water.

Biology

Acanthozoon species look very much like Thysanozoon species. They are only positively identified by microscopic examination: Acanthozoon has only one male pore while Thysanozoon has two.