They are arranged in small clumps
of 4 - 8 pairs and turn partially around the axis of the stolon at the distal
(far) end. The proximal (near) end of the stolon often remains bare. Color is
from white to tan, with light chitinization apparent.
Other Taxonomic Groupings:
Potentially Misidentified Species:
Superficially resembles Amathia distans, but
has a wider stolon with somewhat stiffer branches.
II. HABITAT AND
A. vidovici is
highly cosmopolitan and occurs in the western Atlantic from Massachusetts south
to the Gulf of Mexico and the Caribbean. In the Pacific Ocean, it occurs from
California to the Galapagos Islands. It is also found in the Mediterranean, the
eastern Atlantic, and the Indian Ocean.
A. vidovici is
found year-round in the Indian River Lagoon between Sebastian and Ft. Pierce
Inlets. Coastally it has been collected at Seminole Shores and other sites. It
is also commonly observed in the spring attached to the Rhodophyte Solieria
tenera in the Sebastian seagrass flats.
III. LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Individual zooids measure approximately 0.4 mm in
height. Stolons are wider than those of A. distans and measure
0.3 - 0.20 mm.
A. vidovici is
one of the most abundant bryozoans in the Indian River Lagoon (Winston 1995). It
is most common in the winter months.
The embryology of A. alternata is unknown.
IV. PHYSICAL TOLERANCES
As a highly cosmopolitan species, A. vidovici
is considered to be eurythermal.
A. vidovici was
typically collected in areas where salinity exceeded 30‰ (Winston 1995).
V. COMMUNITY ECOLOGY
like all bryozoans, is a suspension feeder. Each individual zooid in a colony
has ciliated tentacles that are extended to filter phytoplankton less than 0.045
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 can clear 8.8 ml of
water per day.
Typical habitat for ectoprocts in the Indian River
Lagoon include seagrasses, drift algae, oyster reef, dock, pilings, breakwaters,
and man-made debris (Winston 1995). A. vidovici occurring in the IRL were
collected from rocks, seagrasses and algae.
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,
VI. SPECIAL STATUS
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
Report by: K. Hill,
Smithsonian Marine Station
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Page last updated: July 25, 2001