Order : NUDIBRANCHIA
Infraorder : CLADOBRANCHIA
Parvorder : EUARMINIDA
Superfamily : ARMINOIDEA
Family : Arminidae
Body with white ridges usually bearing a median yellow line. Between the ridges, the ‘valleys’ are a darker translucent grey or yellow.
Dermatobranchus albus (Eliot, 1904) “Back white with distinct low ridges, longitudinal but not parallel to median line, each with a yellow line along its summit. The rhinophores stand vertically or point forwards and bear longitudinal perfoliations. The base is white, the main part black, the apex truncated and yellow. They are not retractile into pockets, but can be withdrawn under the mantle-edge. They are not very sensitive. The large velum and the mantle are edged with bright yellow. Foot not half the width of mantle. In crawling, the underside of the mantle is applied to the substratum over which the animal moves. Length 13 mm, breadth 4 mm.”
Dermatobranchus albus (Edmunds & Thompson, 1972): “The two animals were 16 and 9 mm long alive and they crawled actively in captivity. Dorsally the mantle has a series of almost parallel longitudinal ridges and grooves. The ridges have a yellow crest with white sides, and the grooves are grey. The edge of the mantle is yellow. Between the rhinophores the mantle is continuous with the head, unlike Armina which has a ridge and a groove here. The oral veil is white with a broad yellow anterior border. The rhinophores are white at the base with a yellow club and tip, but the club has dense black spots so appears dark. There are about eight longitudinal ridges on the club. The foot is rounded anteriorly with angled corners. Preserved, it is rounded with rounded corners. On the ventral surface, both the mantle and the foot are white. As usual in this family, there are openings of glands all along the edge of the mantle on the ventral side, but there are no lateral lamellae or gills such as occur in Armina. The smaller animal has a similar pattern to the larger one except that many of the yellow ridges on the mantle are discontinuous.”