Regional Distribution Map
|Bioregion||Region Name||Year||Invasion Status||Population Status|
|NEP-I||Alaska north of the Aleutians||1998||Def||Estab|
|NEP-III||Alaskan panhandle to N. of Puget Sound||1927||Def||Estab|
|NEP-IV||Puget Sound to Northern California||1970||Def||Estab|
|NEP-V||Northern California to Mid Channel Islands||1952||Def||Estab|
|P292||_CDA_P292 (San Juan Islands)||1969||Def||Estab|
|P297||_CDA_P297 (Strait of Georgia)||1974||Def||Estab|
|P293||_CDA_P293 (Strait of Georgia)||1927||Def||Estab|
|P112||_CDA_P112 (Bodega Bay)||1975||Def||Estab|
|P090||San Francisco Bay||1963||Def||Estab|
|P116||_CDA_P116 (Big Navaro-Garcia)||2001||Def||Estab|
|NEP-VI||Pt. Conception to Southern Baja California||2015||Def||Estab|
|P050||San Pedro Bay||2017||Def||Estab|
Schizoporella japonica is a heavily calcified encrusting bryozoan, growing on rocks, shells, and algae. The colonies sometimes form a double layer, due to overgrowth of one colony over another and occasionally form leaf-like lobes free from the substrate. Colonies range in color from whitish pink to deep red and can grow up to 5 cm across. Its zooecia are roughly rectangular, arranged in columns radiating from a center, with distinct grooves at lateral walls. The width of the zooids increases along the column, until a bifurcation point is reached where the zooids are nearly as wide as long. After the bifurcation point, daughter zooids are again narrow and elongate. The frontal wall is somewhat convex, with areolar pores (in circular pits) around the margins, and small pseudopores (not in pits) covering the entire frontal surface. There is often a small umbo (knob) below the orifice. The orifice is broader than long, semicircular on the distal side, with the proximal side separated by a pair of blunt condyles, and forming a broad sinus. The zooecia lack spines and the avicularia may be single, paired, or absent on a zooid. The ovicells are globose, with scattered small pores, and resting on the frontal walls of zooids. They may have a calcified, rough surface and can be scattered among the zooids or form a reproductive band within the colony (description from Dick et al. 2005).
In California, S. japonica is bright orange in color, whereas the similar S. errata tends to be paler. The latter can have adventitious, large, frontal avicularia, though they may be rare. Schizoporella errata is rare on experimental fouling panels, but quite abundant in San Francisco Bay as bryoliths (unattached, living colony masses), whereas S. japonica is very abundant on panels, but has never been seen to form bryoliths (Linda McCann, personal communication 2009).
Schizoporella unicornis var. japonica (Ortmann, 1890)
Potentially Misidentified Species
Several species of Schizoporella have been reported from California waters. One form appears to be the Northeast Atlantic warm-water form S. errata (Linda McCann, personal communication).
This very similar species was newly described is known from California fouling communities, but is not likely to be a native species and may be a redescription of a form of a previously described Schizoporella (James T. Carlton, personal communication, 2013). and is presumed to be native. See Soule et al. 2007) for a description.
One morphotype found in San Diego may be the species described by the Soules from Baja, Cal (Soule and Soule 1964), as S. occidentalae, but more specimens are necessary to confirm the identification (Linda McCann personal communication, 2013)
Dick et al. (2005) have re-examined Schizoporella sp. from Ketchikan, Alaska, and both sides of the Pacific, and have raised Ortmann's S. unicornis var. japonica' to the status of a distinct species, noting differences between this form and British S. unicornis, and similarities between the Japanese type specimen and Alaskan Schizoporella, as well as specimens collected from Smithsonian Environmental Research Center fouling plates from Puget Sound to San Francisco.
Invasion HistoryFirst Non-native North American Tidal Record: 1927
First Non-native West Coast Tidal Record: 1927
First Non-native East/Gulf Coast Tidal Record:
General Invasion History:
The encrusting bryozoan Schizoporella japonica was first described from Sagami Bay, Japan, as a variety of S. unicornis. It is native to the Northwest Pacific, from China to northern Japan (Dick et al. 2005). However, the extent of its native and introduced ranges is uncertain because of confusion with S. unicornis, S. errata, and other Schizoporella species.
North American Invasion History:
Invasion History on the West Coast:
In the Northeast Pacific, Schizoporella japonica has been introduced in many locations, from Alaska to Morro Bay, California, with Pacific Oysters (Crassostrea gigas) from Japan (Powell 1970; Dick et al. 2005). It was first collected on the US West Coast in Samish Bay, Puget Sound in 1927 (McCain and Ross 1974; Ross and McCain 1976, cited by Carlton 1979). Taxonomic uncertainties make it difficult to document the spread of this bryozoan. Powell (1970) reported that in 1969 it was found from central Vancouver Island to Puget Sound and Willapa Bay. It has been found in other coastal bays, including Grays Harbor, Washington (McCain and Ross 1974, cited by Carlton 1979), Coos Bay, Oregon (in 1986, Carlton 1989), and Humboldt Bay (in 1992, Barnhart et al. 1992, cited by Boyd et al. 2002), Fort Bragg Harbor (in 2001, Fairey et al. 2002), Bodega Harbor (Standing et al. 1975, cited by Carlton 1979), Tomales Bay (in 1947, Carlton 1979), Elkhorn Slough (Osburn 1952, cited by Carlton 1979), Monterey Bay (Haderlie 1971, cited by Carlton 1979), and Morro Bay, California (in 1964, Powell 1970). In San Francisco Bay, it was first collected from Berkeley Yacht Harbor (in 1963, Banta 1963, cited by Cohen and Carlton 1995), and it is now widespread in the central and south portions of the Bay (Cohen et al. 2005; Ruiz et al., unpublished data).
To the north, it has been found in Alaska, from Ketchikan (in 2001, Dick et al. 2005, Ruiz et al., 2006), Sitka (in 2001, Ruiz et al. 2006), and Valdez and Tatilek, Prince William Sound (in 1998, Hines and Ruiz 2000). The southern extent of its range is uncertain. Schizoporella on fouling plates from south of Point Conception (Los Angeles-San Diego) appear to represent a different species (Linda McCann, personal communication).
Invasion History Elsewhere in the World:
Introduced populations in Hawaii, Australia, and New Zealand, identified as Schizoporella unicornis, could represent S. japonica (Dick et al. 2005). Molecular and morphological studies will be needed to determine the identity of Schizoporella populations worldwide.
In February 2011, S. japonica was discovered in fouling communities in Holyhead, Wales. Subsequently, populations were found in the Orkney Islands on the east coast of Scotland, Portavadie on the west coast of Scotland (Ryland et al. 2014) and in the Shetland Islands (Collin et al. 2015). In June-July 2014, this bryozoan was found at Floro, Alesund, and Kristiansund, Norway (61-63 S, Porter et al. 2015).
Life History- Schizoporella japonica is an encrusting, calcified bryozoan composed of many individual zooids. The zooids feed by extending the ciliated tentacles of the lophophore as a funnel, creating a current, and driving food particles into their mouths. The food is guided along the tentacles and through the pharynx by the cilia. Larger food particles can be moved or captured by flicking or contracting the tentacles (Barnes 1983). Larvae of the congeneric S. errata are lecithotrophic, and have a short planktonic period (less than 1 day, Hayward and Ryland 1998). This is likely for S. japonica also. Larvae settle on a substrate and metamorphose into the first zooid of a colony, an ancestrula (Barnes 1983).
Ecology- Schizoporella japonica is known from oyster beds, pilings, shells, rocks, algae, and fouling plates (Powell 1970; Dick et al. 2005).
|General Habitat||Coarse Woody Debris|
|General Habitat||Oyster Reef|
|General Habitat||Marinas & Docks|
|General Habitat||Vessel Hull|
|Salinity Range||Polyhaline||18-30 PSU|
|Salinity Range||Euhaline||30-40 PSU|
|Tidal Range||Low Intertidal|
Tolerances and Life History Parameters
|Broad Temperature Range||Cold temperate-Warm temperate|
|Broad Salinity Range||Polyhaline-Euhaline|
General ImpactsEconomic Impacts
Schizoporella spp. are common fouling organisms on ships' hulls, docks, and other hard surfaces (Woods Hole Oceanographic Institution 1952). Ryland (1971) suggests that the calcareous layers produced by the bryozoans may actually protect pilings and docks from borers. Powell (1970) considered that S. japonica (as S. unicornis) had little effect on live oysters, because the bryozoans settled primarily on dead shells and rocks, but were rarely seen on the living animals.
Schizoporella spp. frequently dominate the fouling community on man-made structures and on rocks, shells, and algae (Ryland 1965; Powell 1970; Sutherland 1981; Hayward and McKinney 2002).
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