Dendronotus nanus
Marcus & Marcus, 1967

Family: Dendronotidae


Sonora, Mexico to San Diego, California


La Jolla, San Diego, California, Depth: 46 feet. Length: 3 inches. 31 July 2001. Intertidal sand flats. Photographer: Mark Chapman

Dendronotus nanus, was described from Sonora, Mexico, in 1967 (Marcus & Marcus, 1967) but I can't find any other information on this species. The body is a translucent grey with scattered opaque white spots and an opaque white border to the foot. The branchial and rhinophoral papillae are translucent grey with an opaque white tip, then a median band of black and a lower band of bright orange. Any of these colours can be absent in one or more papillae, and the black band often consists of a few black patches.

There are six pairs of branchial papillae, the anterior pair being the largest. The papillae seem to lack a common stalk or trunk, and so look like a series of cerata arranged in an arch. The anterior papillae around the head consist of 3 rows of relatively small papillae, each with small black secondary papillae.

Gordon Robilliard ( 1972) compares this species with D. iris; and suggests they should be considered distinct, but felt that the question should be re-examined if the geographical distributions were shown to overlap, as they clearly do.

  • Marcus, Er. & Marcus, Ev (1967) American opisthobranch mollusks. Part 2, Opisthobranchs from the Gulf of California. Studies Tropical Oceanography, Miami: 6(1-2), 141-256. (Figs 1-95)
  • Robilliard, G. A. (1972) A new species of Dendronotus from the northeastern Pacific with notes on Dendronotus nanus and Dendronotus robustus (Mollusca: Opisthobranchia). Canadian Journal of Zoology, 50(4): 421-432.
Authorship details
Rudman, W.B., 2005 (August 11) Dendronotus nanus Marcus & Marcus, 1967. [In] Sea Slug Forum. Australian Museum, Sydney. Available from