Alcyonidium pedunculatum Robertson, 1902

Common name(s):  Smooth leather bryozoan

Synonyms:  Alcyonidium pedunculatum
Phylum Bryozoa (Ectoprocta) 
  Class Gymnolaemata
      Suborder Euctenostomata
        Family Alcyonidiidae
Alcyonidium pedunculatum, about 10 cm long.  Colllected at about 75 m depth in San Juan Channel July, 2008
(Photo by: Dave Cowles, July 2008)
Description:   As with all members of Bryozoan Class Gymnolaemata, Order Ctenostomata, the individual zooecia are not calcified and the zooecia are united into a fleshy, leathery, or gelatinous mass or connected by stolons, plus the apertures are closed by a constriction. Alcyonidium pedunculatum has zooecia in an erect, stalked (photo), sheetlike leathery or hard gelatinous mass.  The colony has no spines.  Yellowish or pale pink.  Up to 30 cm tall.

How to Distinguish from Similar Species:Alcyonidium gelatinosum has similar texture but is encrusting. Flustrellidra corniculata is erect but has many forked spines.

Geographical Range:  Alaska to (central BC)--apparently plus the San Juan Islands.

Depth Range:  Subtidal


Biology/Natural History:



Dichotomous Keys:
  Kozloff, 1987, 1996

General References:
  Lamb and Hanby, 2005

Scientific Articles:

Web sites:

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

Closeup of zooids
This closeup of the colony shows the zooids feeding with their lophophores.

In dish
View of another individual, showing the lobed edges of the colony.

The colony grows from a distinct stalk.

Authors and Editors of Page:
Dave Cowles (2008):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)