Species Description:
V. contei forms delicate translucent
white colonies with short branches. Zooids are short, widening
distally and tapering proximally. Zooids measure an average of 0.33 X 0.14 mm in
size, but fertile zooids tend to be shorter. Avicularia are not present in this
species. Rather, there is a long pointed process on either side of the
semicircular orifice. The lophophore measures approximately 0.25 mm in diameter,
and bears 12 tentacles.
Synonymy:
None
Other Taxonomic Groupings:
Suborder: Ascophora
Potentially Misidentified Species:
V. contei is often confused with other
bryozoan species, especially Celloporina costazii.
II. HABITAT AND
DISTRIBUTION
Regional Occurrence:
V. contei is a potentially cosmopolitan
species; however, it has often been confused with other bryozoan species,
especially Celloporina costazii. Its documented range in the western
Atlantic extends from Cape Hatteras south to Florida.
IRL Distribution:
V. contei is found year-round at coastal
stations surrounding the Indian River Lagoon. It has been recorded from several
locations within the Indian River Lagoon, notably from around the Fort Pierce
Inlet; but it is likely to be somewhat more widespread than reported due to its
cryptic nature and small stature.
III. LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Zooids measure an average of 0.33 X 0.14 mm in
size. The lophophore measures approximately 0.25 mm in diameter, and bears 12
tentacles.
Abundance:
V. contei is common around the area of Ft.
Pierce Inlet and Seminole Shores, Florida. It is found year-round along the
coast.
Locomotion:
Sessile
Reproduction:
The reproductive season of this species has not
been well documented.
Embryology:
Ovicells are large and found embedded in the distal
zooid. They are generally outlined by a beaded border, with a longitudinal
groove down the front. The orifice of the ovicell is transversely elongate and
separate from the orifice of the fertile zooid. Embryos are pink to pink-red in
color.
IV. PHYSICAL TOLERANCES
Temperature:
As V. contei is found year-round along the
Florida coast and is thus eurythermal.
Salinity:
V. contei is typically collected at sites
where salinity averages over 30 ‰.
V. COMMUNITY ECOLOGY
Trophic Mode:
V. contei, like all bryozoans, is a
suspension feeder. Each individual zooid in a colony has 12 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.
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). V. contei is highly cryptic in its
habitat preferences and occurs principally in the roots of hydroids such as Thyroscyphus
and Endendrium. It also is found growing on sponges, rocks, breakwaters,
and attached to Sargassum.
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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irl_webmaster@si.edu
Page last updated: July 25, 2001
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