Sagaminopteron nigropunctatum
Carlson & Hoff, 1973

Order: CEPHALASPIDEA
Superfamily: PHILINOIDEA
Family: Gastropteridae

DISTRIBUTION

Possibly widespread in the western Pacific. Records from Guam, Rota (Northern Marianas), Palau, and Cabilao in the Philippines. (See Carlson & Hoff message below.

PHOTO

UPPER: 5.5 mm; Guam, Cocos reef, 8m; 27 September 1970,
On Dysidea granulosa
LOWER: 8.0mm; Palau, Wonder Channel, 13m; 24 September 1996, On Dysidea granulosa with  egg masses.
PHOTOS: C. Carlson & P.J.Hoff.

Sagaminopteron nigropunctatum is well camouflaged on the grey sponge on which it is usually found, the colouring and texture being almost identical. It is a translucent greyish with fine black specks and light grey to cream coloured pustules, the upper photo showing a 'typical' example. There is some variation in the background colour with some animals appearing translucent cream, and the black speckling varies from dense to very sparse in different animals. The edges of the siphon are usually orange, and sometimes the tip of the siphon as well. There are two distinctive orange spots on the headshield, one at each anterior corner, and the flagellum is also often edged with orange. In different specimens varying numbers of other orange specks can be found.

It is always found associated with a species of the sponge Dysidea and compared with other gastropterids, S. nigropunctatum is reported to be rather 'sluggish' seldom seen to swim.

Reference:
• Carlson, C.H. & Hoff, P.J. (1973). Two new species of Gastropteridae from Guam, Marianas Islands (Opisthobranchia: Cephalaspidea). Publications of the Seto Marine Biological Laboratory, 21(2): 141-151.

See Carlson & Hoff message for further photos.

Authorship details
Rudman, W.B., 1999 (August 5) Sagaminopteron nigropunctatum Carlson & Hoff, 1973. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/saganigr

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