ANASPIDEA in the Red Sea

Erwin, Its a bit difficult from the angle of your photo to be sure but I am pretty sure it is the circum-global Dolabrifera dolabrifera. As you suggest it is a member of the Anaspidea, and could be considered almost a "limpet" version of the sea-hares. It is much more flattened than most of its relatives and it is a very characteristic leech-like form of locomotion, the posterior foot forming a large rounded sucker while the neck and head, raised off the ground, stretch ahead. The head then makes contact with the ground and the posterior part of the body is drawn forward. Dolabrifera dolabrifera is now considered to be a single world-wide species, although there are clearly some quite distinct "forms". In southeastern Australia there is a large form, growing to more than 12cm long unstretched. It was previously named Dolabrifera brazieri. It has a smooth skin and distinctive low rounded tubercles. In the tropical Pacific the common for is seldom more than 4cm long, ranges in colour from mottled reddish pink, to brown or green. It usually has low papillae on its skin giving it a "hairy" or "furry" appearance. Your animal seems to have a smoother appearance, more like a typical Aplysia. Dolabridera dolabrifera has a very characteristic egg mass, the ribbon being layed flat onto a hard surface in a tight zigzag pattern ... Bill Rudman