Noumea norba
Marcus & Marcus, 1970

Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Chromodorididae

DISTRIBUTION

Widespread in tropical Indo-West Pacific

PHOTO

Split Solitary Is, Coffs Harbour, northern New South Wales, December 1990. Lower photo showing two animals on sponge with eggs, 70ft (approx 24m), PHOTOS: C. Buchanan.

In Noumea norba the background colour of the mantle can vary from reddish purple to pinkish orange in different specimens. There is a broad milky yellow or creamy white band around the mantle edge and on the inside edge of this band are a series of reddish purple streaks or smudged marks. In the midline there is a broad band of irregular width of the same colour as the mantle border. This band always encircle the gill pocket and can be broken in two about half way along its length. The gills and rhinophores are tinged with orange-red. Noumea norba and Noumea varians are quite similar in colour however their internal anatomy is quite different. One way of distinguishing living animals is that N. norba is quite like a species of Chromodoris in shape with a relatively wide flattened body and broad mantle skirt while N. varians is more like a Hypselodoris with a relatively high body and narrow mantle skirt.

In an earlier revision (Rudman, 1986) I considered this species to be a synonym of Noumea purpurea but now that we no more about the anatomy and colour variation in that species, they are clearly distinct.

See the Noumea purpurea Colour Group Page to compare this species with others of similar colour.

Reference:
•Rudman, W.B. (1986) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Noumea purpurea and Chromodoris decora colour groups. Zoological Journal of the Linnean Society 86(4): 309-353.

Authorship details
Rudman, W.B., 1999 (December 5) Noumea norba Marcus & Marcus, 1970. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/noumnorb

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