Description: This tiny nudibranch lives and feeds on the bryozoan Membranipora membranacea, and blends in to the surface patterns extremely well. Instead of having a ring of gills around the posterodorsal anus, the anus is on the posterior midline of the body in the groove between the foot and the dorsum and it has 1-2 gills on each side of the anus (photo). The dorsum is smooth without dorsal tubercles, ridges, nor cerata, but does have simple, tapered rhinophores (photo) and a pattern of gray and yellow-brown spots and white lines that look very much like the pattern of zooids on the surface of M. membranacea. There is no notch on the posterior border of the dorsum. Length to 1.7 cm but usually 5 mm or less. Many may be only 1 mm long.
How to Distinguish from Similar Species:Corambe pacifica has a notch on the posterior dorsum and has 6-14 gills.
Geographical Range: Central Alaska to Baja California, Mexico
Depth Range: Intertidal and subtidal
Habitat: Lives and feeds on the bryozoan Membranipora membranacea, which lives on various species of kelp.
History: In Washington
it lays tiny masses of eggs in individual capsules in July and August,
attached to the kelp. The egg masses of C.
steinbergae are curved but never exceed one complete turn
while those of C.
which may be found in similar places, usually have more than one and
have 2-3 turns (Anderson, 1971). The larvae hatch as a trochophore,
to a veliger and swim for about a month, and settle on kelp
membranacea which are being attacked by this
develop large spines on some of the zooids
within 36 hours, which decreases the rate of feeding of the nudibranchs.
may be found on M.
membranacea year-round but is most abundant in
summer when kelp
growth is most robust.At Friday Harbor in the summer, this nudibranch
can reach a density of 240 individuals per plant for Laminaria
saccharina kelp less than 1 m long (Seed, 1976).
Kozloff, 1987, 1996 (as Doridella steinbergae)
Lance, James Robert, 1962. A new Stiliger and a new Corambella (Mollusca: Opisthobranchia) from the northeastern Pacific. Veliger 5:1 pp 33-38, plate 6, and figures 6-10.
Seed, R., 1976. Observations on the ecology of Membranipora (bryozoa) and a major predator Doridella steinbergae (nudibranchiata) along the fronds of Laminaria saccharina at Friday Harbor, Washington. Journal of Experimental Marine Biology and Ecology 24:1 pp 1-17
Turner, Teresa, 1978. Adaptive significance of foot forms and types of locomotion in Opisthobranchs. M.A. Thesis, California State University, Hayward. 66 pp.
General Notes and Observations: Locations, abundances, unusual behaviors:
Authors and Editors
Salish Sea Invertebrates web site provided courtesy of Walla