Bugula neritina (Linnaeus, 1758)

Brown bryozoan

Phylum Ectoprocta
Class Gymnolaemata
Order Cheilostomata
Family Bugulidae

Description
Flexible bushy colonies, branching biserial, to about 10 cm high. Color is purplish-brown. Zooids alternating, with the outer corner pointed, but not spined. No avicularia, ovicell large, white, and globular (from Gordon & Mawatari, 1992).
Habitat
Typically found in harbors and embayments, especially Pearl Harbor, intertidal to 5 m, attached to any available hard substrate.
Distribution
Hawaiian Islands
Throughout the main islands, in harbors, embayments, and shallow reef areas.
Native Range
Unknown, perhaps the Mediterranean
Present Distribution
Worldwide in tropical and temperate seas
Mechanism of Introduction
Unintentional, most likely as fouling on ships' hulls.
Impact
Fouling organism. Ecological impact unstudied, likely some competition for space with native species.
Ecology
Feeding
The bryozoan is a suspension feeder. It has a retractable U-shaped crown of tentacles (lophophore) which bear cilia that create a current, bringing food particles toward the animal. Particles are then guided into the mouth by action of the tentacles and cilia.
Reproduction
Each bryozoan colony begins from a single, sexually produced, primary zooid. This zooid undergoes asexual budding to produce a group of daughter cells, which themselves form buds, and so on. Most bryozoans are hermaphroditic, each zooid capable of producing sperm and eggs. Sperm is released into the coelom and the fertilized eggs are retained and brooded for a time before being released.
Remarks
A common fouling organism worldwide, reported from all seas except subarctic and subantarctic regions, this species is most likely a suite of very similar species. It's presence in Hawaii was first reported by Edmondson (1933). He noted that it was one of the most common fouling species in harbors and bays around Oahu. It has since been widely reported throughout the main Islands by a number of authors.
Recently, B. neritina has been a subject of a great deal of biochemical research. It is the source of a novel chemical, bryostatin, which has been shown been effective against leukemia.
There are three additional alien species of Bugula reported in Hawaii; B. dentata, B. robusta, and B. stolonifera (Zabin, 1999).
References
Edmondson, C.H. 1933. Reef and Shore Fauna of Hawaii. B.P. Bishop Museum Spec. Pub. 22.
Gordon, D.P. and S.F. Mawatari. 1992. Atlas of marine-fouling Bryozoa of New Zealand ports and harbours. New Zealand Oceanographic Institute, Pub. 107: 1- 52.
Zabin, C.J. 1999. New records of introduced fouling Bryozoa from Oahu, Hawaii. Occ. Pap. Bishop Mus. 59: 46-47.