Bugula stolonifera Ryland
Family: Bugulidae
Bugula stolonifera image
Bugula stolonifera  

Species Description: Colonies of B. stolonifera are erect and branching. Young colonies take on a fan or funnel shape, while established colonies form dense tufts. Color is a grayish tan overall. Zooids of B. stolonifera are smaller than those of B. neritina, yet still taper proximally. They average 0.78 X 0.19 mm in size and have a U-shaped frontal membrane that occupies 3/4 of the frontal surface.

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 birds' 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.

Regional Occurrence: B. stolonifera 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 Brazil.

IRL Distribution: B. stolonifera 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 Capron Shoals.

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 in diameter.

Abundance: B. stolonifera is among the most abundant species of bryozoa in the Indian River Lagoon. It is an important member of the fouling community.

Locomotion: Sessile

Embryology: Yellow-brown embryos are brooded in subglobular ovicells. Larval settlement occurs from December to April.

Temperature: B. stolonifera 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).

Salinity: In the Indian River Lagoon, B. stolonifera is typically collected in areas where salinity is below 30‰.

Trophic Mode: B. stolonifera, 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.

Habitats: Typical habitat for ectoprocts in the Indian River Lagoon include seagrasses, drift algae, oyster reef, dock, pilings, breakwaters, and human-made debris (Winston 1995). B. stolonifera in the IRL attaches to a wide variety of substrata, including B. neritina.

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. B. stolonifera in the IRL typically occurs in association with B. neritina.

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.

Winston JE. 1982. Marine bryozoans (Ectoprocta) of the Indian River area (Florida). Bull Amer Mus Nat Hist 173: 99-176.

Winston JE. 1995. Ectoproct diversity of the Indian River coastal lagoon. Bull Mar Sci 57: 84-93.

Bugula stolonifera image
Bugula stolonifera