Flatworm Discodoris

Description

Colour usually translucent white with dark brown patches, the amount of dark brown varying between individuals. The gill and rhinophore pockets are raised. The rhinophore stalk and club are dark brown with a white line up the posterior midline of the stalk and along the anterior (upper) surface of the club. The dark brown gills have a distinct pattern of white lines. It has the narrow visceral hump, (which forms a narrow median ridge from the rhinophores to the gills), and wide mantle skirt, often autotomised when disturbed. Under the mantle skirt is the foot with another pair of tentacles. This nudibranch reaches a length of 12 centimetres. People should avoid handling the animal as it easily breaks off (autotomises) portions of its body (mantle skirt).

Distribution

Indo-West Pacific region from the eastern coasts of Africa to the Papua New Guinea, Vanuatu and Solomon Islands.

Habitat

It is usually hidden during the day, so its fast crawling may have been caused by its trying to find somewhere to hide. Of course its little brain can't actually think about such things, but many animals that hide during the day are what is called photokinetic that is they move quite fast when they are in the light, and stop or slow down considerably when they are in the dark. This helps to get them to a dark place, which ususally means a shaded overhang or crevice where they can hide. It feeds on sponges and inhabits shallow coral reefs. They are simultaneous hermaphrodites. Mating behavior: both individuals darts their penis toward each other to induce one to act as a male and the other as the female. The victorious one to penetrate the body wall is the dominant male. Life cycle: eggs are deposited on a substratum where they develop and hatch into (planktonic) vestigial veliger larval stage and further grow as adults