Membraniporidae Busk, 1852

Colonies encrusting or erect; unilaminar or bilaminar; weakly to well-calcified. Zooids with vertical and basal calcified walls, but virtually no frontal calcified wall: most of the frontal surface is occupied by frontal membrane. Intertentacular organ present. Spines or tubercles may be present at corners of zooid.Spines at the margin of the opesia in few species. Larvae not brooded; planktotrophic, of bivalved (cyphonautes) form where known. Ancestrulae generally twinned. Kenozooids may be present in a few species; modified zooids analogous to avicularia are rare.

This family includes the genera

1. Acanthodesia
2. Biflustra
3. Conopeum Now in Electridae
4. Jellyella
5. Membranipora
6. Tamanicella (Now in Electridae)

The family is often used as a "catch-all" for anascans with little or no calcification of the frontal wall, and no information about larval brooding. Many bryozoans have been assigned to the the family with insufficient information about relationships.

It has been proposed (by Taylor & Monks 1997) to restrict the definition of the family to the genera whose members develop from a twinned ancestrula. The genus Conopeum then would be placed provisionally in the family Electridae.

The genus Parastichopora is similarly excluded from the Membraniporidae, but its relationships with other families are still uncertain.

Reference: Taylor, Paul D. & Monks, Neale, 1997. A new cheilostome genus pseudoplanktonic on molluscs and algae. Invertebrate Biology, 116: 39-51.

Biflustra arborescens	Biflustra perfragilis	Biflustra savartii	Membranipora membranacea
Jellyella eburnea	Jellyella tuberculata (thanks to Dennis Gordon, NIWA)

Membranipora membranacea by Peter J. Bryant - at Natural History of Orange County.
Jellyella tuberculata by Peter J. Bryant - at Natural History of Orange County.

Biflustra page at NMITA

Biflustra denticulata at The Bryozoans of the Pacific.

Membranipora membranacea at Encyclopedia of Marine Life of Britain and Ireland, Ulster Museum.

Membranipora membranacea - at the British Columbia Creature Page.

Membranipora - at MBL/WHOI Web Site.

Membranipora membranacea - from San Francisco, at the California Academy of Sciences.

Photos of Membranipora sp. - at Phillip Colla Photography.

Parastichopora vanna. This genus has been placed in the family, but here is included with the group of cheilostomes of uncertain affinities.