Cauloramphus spiniferum (Johnston, 1832)

Common name(s): 

Phylum Bryozoa (Ectoprocta)
Class Gymnolaemata
Order Cheilostomata
Suborder Anasca
Family Hincksinidae
Cauloramphus spiniferum is seen above as the bryozoan patch to the left within the mouth of a small moon snail collected at 120 m depth west of Yellow Island, San Juan Channel, WA.  The patch is 5 mm long vertically.  The bryozoan to the right is Lichenopora verrucaria.
(Photo by: Dave Cowles, July 2007)
Description:  Like other Cheilostome bryozoans, this species has calcified zooecia and the opening is not closed by a constriction.  Cauloramphus spiniferum makes a crustlike colony which forms a patch rather than an elongated stolon.  The zooecia have an operculum and spines.  A large portion of the frontal of the zooecium is an uncalcified membrane and protected by straight, simple spines around the margin.  The avicularia are tall and slender, stalked, and found among the spines.  The zooecia are not separated from one another by grooves.

How to Distinguish from Similar Species:  Cauloramphus brunea and C. echinus have large grooves between the zooids.

Geographical Range:

Depth Range:


Biology/Natural History:



Dichotomous Keys:
  Kozloff 1987, 1996
  Smith and Carlton, 1975

General References:

Scientific Articles:
Wollacott, Robet M. and Wheeler J. North, 1971.  Bryozoans of California and northern Mexico kelp beds.  pp. 455-479 in North, Wheeler J. (ed.), The Biology of Giant Kelp Beds (Macrocystis) in California.  Beihefts zur Nova Hedwigia Heft 32.  Publisher: J. Cramer, Lehre, Germany.

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:

This closeup shows the individual zooids.  Note that the frontal area of the zooids is soft and membranous but it is protected by a sheath of spines around the margin.
Here and there among the spines are thicker, stalked clublike avicularia.  There are no large grooves between the zooids.

Here is a full view of the moon snail shell, which has a diameter of 2.6 cm in this view.
Cauloramphus spiniferum is the bryozoan colony farthest inside the shell mouth (the topmost colony in this view).
The other two colonies are Lichenopora verrucaria (middle left) and Lichenopora novae-zelandiae (bottom right).

Authors and Editors of Page:
Dave Cowles (2007):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)