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Species Name:    Synnotum aegyptiacum
Common Name:                          (None)

 

I.  TAXONOMY

Kingdom Phylum/Division: Class: Order: Family: Genus:
Animalia Ectoprocta Gymnolaemata Cheilostomata Epistomiidae Synnotum


SEM of Synnotum aegyptiacum, an erect, branching bryozoan.  Photo by J. Winston, courtesy of the American Museum of Natural History.  Used with permission.
Species Name:
Synnotum aegyptiacum (Audouin), 1826

Voucher Specimen: 
American Museum of Natural History 
# 597

Common Name:
None



Species Description:
S. aegyptiacum forms erect, branching and stolonate colonies that resemble strings of glass beads. Zooids are scoop-shaped and occur in pairs, back to back along branches, with joints between each pair. Zooids have large frontal areas that are lightly calcified, and measure approximately 0.24 X 0.10 mm on average. Two types of avicularia are present: box-shaped, sessile avicularia located in the distal corners of zooids, and bulbous pedunculate avicularia located on the dorsal surface. Radicles used for attachment to the substratum may have elaborate hook-like ends. The lophophore averages 0.231 mm in diameter and bears 10 tentacles.

Synonymy:
Loricaria aegyptica Audouin, 1826
Synnotum aviculare Osburn, 1914

Other Taxonomic Groupings:
Suborder: Anasca


II.  HABITAT AND DISTRIBUTION 
Regional Occurrence:
S. aegyptiacum is highly cosmopolitan in warm waters. In the western Atlantic, this species is distributed from Cape Hatteras south to Florida, the Gulf of Mexico, the Caribbean and Brazil.

IRL Distribution:
S. aegyptiacum occurs year-round at coastal stations and within the IRL, though IRL colonies may sometimes overwinter in a dormant state.


III.  LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Individual zooids average 0.24 X 0.1 mm in size. The lophophore measures an average of 0.231 mm in diameter and bears 10 tentacles.

Abundance:
S. aegyptiacum colonies are large and abundant between October and December.

Locomotion:
Sessile

Reproduction:
Midsummer is the likely reproductive season for this species, as zooids containing sperm were reported in July (Winston 1982). No ovicells are present in this species.

Embryology:
Embryos are brooded inside gonozooids that become enlarged when embryos are present.


IV.  PHYSICAL TOLERANCES
Temperature:
S. aegyptiacum is considered to be a warm water species. It is collected year-round in the IRL, but colonies may overwinter in a dormant state. Winston (1982) reported that colonies collected in January from Sebastian Inlet contained only brown bodies in distal zooids, and had granular, starchy material in proximal zooids.

Salinity:
S. aegyptiacum is typically collected at locations where salinity exceeds 30.


V.  COMMUNITY ECOLOGY
Trophic Mode:
S. aegyptiacum, like all bryozoans, is a suspension feeder. Each individual zooid in a colony has 10 ciliated tentacles that are extended to filter phytoplankton less than 0.045 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 could 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). S. aegyptiacum is typically found entangled among hydroid stems, primarily Thyroscyphus and Eudendrium species. It has also been documented to colonize both benthic and floating algae, and may utilize other substrata such as shell fragments and beach rock. It has also been collected from depths of 10 m from Capron Shoals, Florida (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