Hippodiplosia insculpta (Hincks, 1882)

Common name(s): Fluted bryozoan, fluted coral bryozoan, sculptured bryozoan

Synonyms: Schizoporella insculpta
Phylum Bryozoa (Ectoprocta) 
Class Gymnolaemata 
Order Cheilostomata 
Suborder Ascophora 
Family Schizoporellidae 
Hippodiplosia insculpta, found under a rock.
(Photo by: Dave Cowles, July 2009 )
Description:   Bryozoans of Class Gymnolaemata have zooids which are polymorphic and usually not cylindrical, with a circular lophophore.  Order Cheilostomata has box-shaped zooids with calcareous walls, the openings of which usually have opercula.  Embryos are usually brooded in ovicellsHippodiplosia insculpta has an erect (not simply encrusting), leaflike colony.  Most of the frontal region of the zooecia is calcified and covered with large pores which are not arranged in rows.  The frontal is not rough.  No avicularia or ascopores are present (but Carlton says the suboral depression mentioned below may have a tiny avicularium in Hippoporina insculpta).  Ovicells are large and globular, without pores but with radiating ribs.  The rim of the aperture of the zooecia is raised into a peaked mound (umbo) which is separated from the aperture by a deep depression (but it has no pointed proximal tooth nor a U-shaped sinus).  Young colonies may be flat but quickly extend into leaflike projections, especially when growing under rocks.  Color yellow to yellow-brown, often growing in double sheets.  May have orange borders, especially when ova are present.  Individual zooecia are about 0.3 to 0.4 by 0.5 to 0.7 mm and rectangular to hexagonal.  The largest individuals are found at colder latitudes.  Colonies up to 15 cm diameter.

Note:  Part of this species has now been split off as Hippoporina insculpta.

How to Distinguish from Similar Species:  The color and growth form of this colony with the large, striated ovicells without pores and no avicularia is distinctive.

Geographical Range:  Alaska to Gulf of California and Costa Rica

Depth Range:  Lower intertidal to over 234 m

Habitat:  Rocks, shells, hydroids, algae, and other bryozoans, on some polychaete worm tubes, pilings; especially in areas with substantial water movement.

Biology/Natural History:

This species may sometimes host the entoproct Loxosomella sp.  Predators include the topsnail Calliostoma canaliculatum.



Dichotomous Keys:
  Carlton, 2007 (on Hippoporina insculpta)
  Flora and Fairbanks, 1966
  Kozloff, 1987, 1996

General References:
  Harbo, 1999
  Lamb and Hanby, 2005
  Morris et al., 1980
  Ricketts et al., 1985

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:

Authors and Editors of Page:
Dave Cowles (2009):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)