Typical branching pattern in this species is Type 4. The outer distal corner of
zooids is elongated into a large spine that often has 1 or 2 smaller spines
directly below it. The inner distal corner also has a spine. Pedunculate
avicularia, shaped like bird's heads, are located down the lateral edge of the
frontal membrane. Round avicularia with decurved beaks occur in 3 size classes
(Small, medium and large) depending on their position with respect to branch
bifurcations. The lophophore bears 14 tentacles and is obliquely truncate,
measuring an average of 0.441 mm in diameter.
Other Taxonomic Groupings:
II. HABITAT AND
commonly occurs in both the eastern and western Atlantic Ocean, and the
Mediterranean. In the western Atlantic, B. stolonifera occurs along the
U.S. east coast from Massachusetts to Florida, through the Gulf of Mexico, to
is a common fouling species along the Florida coast, and in the Indian River
Lagoon. It has been collected from the Sebastian Inlet area, Link Port, and from
other locations in the IRL. Along the Florida coast, it has been collected at
III. LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Individual zooids measure an average of 0.78 X 0.19
mm. The lophophore bears 14 tentacles and measures an average of 0.441 mm
is among the most abundant species of bryozoa in the Indian River Lagoon. It is
an important member of the fouling community.
Yellow-brown embryos are brooded in subglobular
ovicells. Larval settlement occurs from December to April.
IV. PHYSICAL TOLERANCES
is less tolerant of warming temperatures than is B. neritina. Young colonies are
not successfully established in the IRL after early May, and older colonies
appear not to over summer (Winston 1982).
In the Indian River Lagoon, B. stolonifera
is typically collected in areas where salinity is below 30‰.
V. COMMUNITY ECOLOGY
like all bryozoans, is a suspension feeder. Each individual zooid in a colony
has 14 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). B. stolonifera in the IRL attaches to
a wide variety of substrata, including B. neritina.
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. B. stolonifera in the IRL typically occurs in association with B.
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 day.
Report by: K. Hill,
Smithsonian Marine Station
Submit additional information, photos or comments to:
Page last updated: July 25, 2001