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Species Name:    Membranipora savartii
Common Name:                         (None)

 

I.  TAXONOMY

Kingdom Phylum/Division: Class: Order: Family: Genus:
Animalia Ectoprocta Gymnolaemata Cheilostomata Membraniporidae Membranipora


SEM of Membranipora savartii, an encrusting bryozoan.  Note heavy calcification and pattern of fine tubercles along the frontal surface.  Photo by J. Winston, courtesy of the American Museum of Natural History.  Used with permission.  
Species Name:
Membranipora savartii (Audouin), 1926

Voucher Specimen
American Museum of Natural History
# 579

Common Name:
None

 

 


Species Description:
M. savartii forms encrusting colonies that may be one or more layers thick. Zooid shape varies from elongate to rectangular or quadrangular. Individuals measure an average of 0.27 X 0.55 mm. A variable denticulated (toothed) shelf is formed under the proximal half of the frontal surface. Proximal teeth are variable in number or absent. Zooid walls are heavily calcified and have fine tubercles. No avicularia are present.

Synonymy:
None

Other Taxonomic Groupings:
Suborder: Anasca


II.  HABITAT AND DISTRIBUTION 
Regional Occurrence:
M. savartii is highly cosmopolitan in warm water areas. In the western Atlantic, it ranges from the Carolinas to Brazil, including Florida, the Gulf of Mexico and the Caribbean.

IRL Distribution:
M. savartii was collected from the Sebastian Inlet area, both at the inlet, and in the adjacent grass flat areas (Winston 1982). It was also collected from coastal stations at Walton Rocks, Seminole Shores, and on Capron Shoals.


III.  LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Individual zooids measure an average of 0.27 X 0.55 mm.

Abundance:
M. savartii occurs year round, but is most abundant in April and October. In the IRL, it is considered a fouling organism (Winston 1995).

Locomotion:
Sessile

Reproduction:
No ovicells are present in this species.  Like other membraniporids, Membranipora savartii spawns small eggs which develop into planktonic cyphonautes larvae.


IV.  PHYSICAL TOLERANCES
Temperature:
As it is present year-round, M. savartii is considered to be eurythermal.

Salinity:
M. savartii was typically collected in areas where salinity exceeded 30 (Winston 1995).


V.  COMMUNITY ECOLOGY
Trophic Mode:
M. savartii, like all bryozoans, is a suspension feeder. Each individual zooid in a colony has ciliated tentacles that are extended to filter phytoplankton less than 0.05 mm in size (about 1/1800 of an inch) from the water column. Bullivant (1967; 1968) showed that the average individual zooid in a colony can clear 8.8 ml of water per day.

Habitats:
Typical habitat for ectoprocts in the Indian River Lagoon include seagrasses, drift algae, oyster reef, dock, pilings, breakwaters, and man-made debris (Winston 1995). M. savartii was typically found on dead shells and rock substrata at all locations (Winston 1982).

Associated Species:
Seagrasses as well as floating macroalgae, provide support for bryozoan colonies. In turn, bryozoans provide habitat for many species of juvenile fishes and their invertebrate prey such as polychaete worms, amphipods and copepods (Winston 1995).

Bryozoans are also found in association with other species that act as support structures: mangrove roots, oyster beds, mussels, etc.


VI.  SPECIAL STATUS
Special Status:
None.

Benefit in IRL:
Bryozoans are ecologically important in the Indian River Lagoon due to their feeding method. As suspension feeders, they act as living filters in the marine environment. For example, Winston (1995) reported that bryozoan colonies located in 1 square meter of seagrass bed could potentially filter and recirculate an average of 48,000 gallons of seawater per day.

Economic Importance:
None.

 

Report by:  K. Hill, Smithsonian Marine Station
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Page last updated: July 25,  2001