Schizoporella japonica

Invasion History

First Non-native North American Tidal Record: 1927
First Non-native West Coast Tidal Record: 1927
First Non-native East/Gulf Coast Tidal Record: 2022

---

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Carlton 1995), and it is now widespread in the central and south portions of the Bay (Cohen et al. 2005; Ruiz et al., unpublished data).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).

---

Description

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).

---

Taxonomy

Ecology

General:

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).

Food:

Phytoplankton

Trophic Status:

Suspension Feeder

SusFed

---

Habitats

General Habitat	Coarse Woody Debris	None
General Habitat	Oyster Reef	None
General Habitat	Marinas & Docks	None
General Habitat	Rocky	None
General Habitat	Vessel Hull	None
Salinity Range	Polyhaline	18-30 PSU
Salinity Range	Euhaline	30-40 PSU
Tidal Range	Subtidal	None
Tidal Range	Low Intertidal	None
Vertical Habitat	Epibenthic	None

---

---

Tolerances and Life History Parameters

Broad Temperature Range	None	Cold temperate-Warm temperate
Broad Salinity Range	None	Polyhaline-Euhaline

General Impacts

Economic 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.

Ecological Impacts

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).

---

References

Aarnio, Katri; Törnroos, Anna; Björklund, Charlotta; Bonsdorff, Erik (2015) Food web positioning of a recent coloniser: the North American Harris mud crab Rhithropanopeus harrisii (Gould, 1841) in the northern Baltic Sea, Aquatic Invasions 10: In press

Barnes, Robert D. (1983) Invertebrate Zoology, Saunders, Philadelphia. Pp. 883

Bishop, John D. D.; Wood, Christine A.; Lévêque, Laurent; Yunnie, Anna L. E.; Viard, Frédérique (2015b) Repeated rapid assessment surveys reveal contrasting trends in occupancy of marinas by non-indigenous species on opposite sides of the western English Channel, Marine Pollution Bulletin 95: 699-706

Bishop, John D.D.; Wood, Christine A.; Yunnie, Anna L. E.; Griffiths, Carly A. (2015a) Unheralded arrivals: non-native sessile invertebrates in marinas on the English coast, Aquatic Invasions 10: 249-264

Boyd, Milton J.; Mulligan, Tim J; Shaughnessy, Frank J. (2002) <missing title>, California Department of Fish and Game, Sacramento. Pp. 1-118

Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America., Ph.D. dissertation, University of California, Davis. Pp. 1-904

Carlton, James T. (1989) <missing title>, <missing publisher>, <missing place>. Pp. <missing location>

Carlton, James T. (Ed.) (2007) The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon Fourth Edition, Completely Revised and Expanded, University of California Press, Berkeley. Pp. <missing location>

Cepeda, D.; Rodriguez-Flores, P. C. (2017) First record of the invasive worm Branchiomma bairdi(Annelida: Sabellidae) in the Balearic Sea (Western Mediterranean), Journal of the Marine Biological Association of the United Kingdom 98(Special Issue 8): 1955-1963

Cohen, Andrew N. and 10 authors (2005) <missing title>, San Francisco Estuary Institute, Oakland CA. Pp. <missing location>

Cohen, Andrew N. and 22 authors (2001) <missing title>, Washington State Department of Natural Resources, Olympia. Pp. <missing location>

Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

Cohen, Andrew N.; Zabin, Chela J. (2009) Oyster shells as vectors for exotic organisms, Journal of Shellfish Research 28(1): 163-167

Cohen, Andrew; and 16 authors. (1998) <missing title>, Washington State Department of Natural Resources, Olympia, Washington. Pp. 1-37

Collin, Samuel B.; Tweddle, Jacqueline F.; Shucksmith, Rachel J. (2015) Rapid assessment of marine non-native species in the Shetland Islands, Scotland, BioInvasions Records 4: In press

Crane, Laura C.; Goldstein, Jason S.; Thomas, Devin W.; Rexroth, Kayla S.; Watts, Alison W. (2021) Effects of life stage on eDNA detection of the invasive European green crab (Carcinus maenas) in estuarine systems, Ecological Indicators 124(107412): Published online

de Rivera, Catherine, and 27 authors (2005) Broad-scale non-indigenous species monitoring along the West Coast in National Marine Sanctuaries and National Estuarine Research Reserves report to National Fish and Wildlife Foundation, National Fish and Wildlife Foundation, Washington, D.C.. Pp. <missing location>

Dick, Matthew H.; Grischenko, Andrei V.; Mawatari, Shunsuke F. (2005) Intertidal bryozoa (Cheilostomata) of Ketchikan, Alaska., Journal of Natural History 39(43): 3687-3784

Faasse, Marco (2012) The exotic isopod Synidotea in the Netherlands and Europe, A Japanese or American invasion (Pancrustacea: Isopoda)?, Nederlandse Faunistiche Mededelingen 108: 103-106

Fairey, Russell; Dunn, Roslyn; Sigala, Marco; Oliver, John (2002) Introduced aquatic species in California's coastal waters: Final Report, California Department of Fish and Game, Sacramento. Pp. <missing location>

Gartner, Heidi N.; Murray, Cathryn Clarke; Frey, Melissa A.; Nelson, Jocelyn C.; Larson, Kristen J.; Ruiz, Gregory M.; Therriault, Thomas W. (2016) Non-indigenous invertebrate species in the marine fouling communities of British Columbia, Canada, BioInvasions Records <missing volume>: <missing location>

Gordon, Dennis P. (2016) Bryozoa of the South China Sea: an overview, Raffles Bulletin of Zoology 34: 604-618

Green, Stephanie J. and 7 authors (2021) Broad-scale acoustic telemetry reveals long-distance movements and large home ranges for invasive lionfish on Atlantic coral reefs, Marine Ecology Progress Series 673: 117-134

Hayward, P.J.; Ryland, J. S. (1998) Cheilostomatous Bryozoa. Part 1: Aeteoidea-Cribilinoidea., Synopses of the British Fauna 10 (2nd edition): 1-366

Hines, Anson H.; Ruiz, Gregory M. (2000) Biological invasions of cold-water coastal ecosystems: ballast-mediated introductions in Port Valdez/Prince William Sound (Final Report), In: (Eds.) . , Valdez, Alaska. Pp. <missing location>

Huang, Zongguo (Ed.), Junda Lin (Translator) (2001) Marine Species and Their Distributions in China's Seas, Krieger, Malabar, FL. Pp. <missing location>

Keppel, E. ; Ruiz, G. M.; Tovar–Hernández, M. A. (2020) Re-description of Parasabella fullo (Grube, 1878) (Polychaeta: Sabellidae) and diagnostic characteristics for detection in California, European Journal of Zoology 87(1): 105-115
DOI: 10.1080/24750263.2020.1721578

Kim, Daemin; Taylor, Andrew T.; Near, Thomas J. (2022) Phylogenomics and species delimitation of the economically important Black Basses (Micropterus), Scientific Reports 12(9113): Published online
https://doi.org/10.1038/s41598-022-11743-2

Liu, Wenliang; Liang, Xiaoli ; Zhu, Xiaojing (2015) A new record and mitochondrial identification of Synidotea laticauda Benedict, 1897 (Crustacea: Isopoda: Valvifera: Idoteidae) from the Yangtze Estuary, China, Zootaxa 4294: 371-380

Llansó, Roberto J.; Sillett, Kristine; Scott, Lisa (2011) <missing title>, Versar, Inc., Columbia MD. Pp. <missing location>

Lu, L.; Levings, C. D.; Piercey, G. E. (2007) Preliminary investigation on aquatic invasive species of marine and estuarine macroinvertebrates on floating structures in five British Columbia harbours, Canadian Manuscript Report of Fisheries and Aquatic Sciences 2814: 2-30

McCain, K. W.; Ross, J. R. P. (1974) Annotated faunal list of cheilostome Ectoprocta of Washington State, Northwest Science 48: 9-16

Murray, Cathryn Clarke, and 5 authors (2014) Spatial distribution of marine invasive species: environmental, demographic and vector drivers, Diversity and Distributions 20: 824-836

Murray, Cathryn Clarke; Pakhomov, Evgeny A.; Therriault, Thomas W. (2011) Recreational boating: a large unregulated vector transporting marine invasive species, Diversity and Distributions 17: 1161-1172

Nall, Christopher R.; Guerin, Andrew J.; Cook, Elizabeth J. (2015) Rapid assessment of marine non-native species in northern Scotland and a synthesis of existing Scottish records, Aquatic Invasions 10(1): 107–121
http://dx.doi.org/10.3391/ai.2015.10.1.11

Needles, Lisa A. (2007) <missing title>, M.S. Thesis, California Polytechnic State University, San Luis Obispo. Pp. <missing location>

Needles, Lisa A.; Wendt, Dean E. (2013) Big changes to a small bay: Introduced species and long-term compositional shifts to the fouling community of Morro Bay (CA), Biological Invasions 15(6): 1231-1251

Porter, Joanne S.; Spencer Jones, Mary E.; Kuklinski, Piotr; Rouse, Sally (2015) First records of marine invasive non-native Bryozoa in Norwegian coastal waters from Bergen to Trondheim, BioInvasions Records 4: In press

Powell, N.A. (1970) Schizoporella unicornis - an alien bryozoan introduced into the Strait of Georgia., Journal of the Fisheries Research Board of Canada 27: 1847-1853

Ribeiro, Romeu S.; Mata, Ana M. T. ; Salgado, Ricardo; Gandra, Vasco; Afonso, Inês; Galhanas, Dina; Dionísio, Maria Ana; Chainho, Paula (2023) Undetected non-indigenous species in the Sado estuary (Portugal), a coastal system under the pressure of multiple vectors of introduction, Journal of Coastal Conservation 27(53): Published online
https://doi.org/10.1007/s11852-023-00979-3

Ruiz, Gregory M. and 6 authors (2006) <missing title>, Prince William Sound Regional Citizens’ Advisory Council & U.S. Fish & Wildlife Service, Edgewater MD. Pp. <missing location>

Ruiz, Gregory M.; Geller, Jonathan (2018) Spatial and temporal analysis of marine invasions in California, Part II: Humboldt Bay, Marina del Re, Port Hueneme, and San Francisco Bay, Smithsonian Environmental Research Center & Moss Landing Laboratories, Edgewater MD, Moss Landing CA. Pp. <missing location>

Ruiz, Gregory; Geller, Jonathan (2021) Spatial and temporal analysis of marine invasions: supplemental studies to evaluate detection through quantitative and molecular methodologies, Marine Invasive Species Program, California Department of Fish and Wildlife, Sacramento CA. Pp. 153 ppl.

Ryland, J. S. (1965) <missing title>, Organization for Economic Co-operation and Development, Paris. Pp. <missing location>

Ryland, J. S. (1971) Bryozoa (Polyzoa) and marine fouling., In: Gareth Jones E.B; Eltringham, S. K.(Eds.) Marine Borers, fungi and fouling organisms of wood. , Paris. Pp. 137-154

Ryland, John S.; Holt, Rohan; Loxton, Jennifer; Spencer Jones, Mary E. ; Porter, Joanne S. (2014) First occurrence of the non-native bryozoan Schizoporella japonica Ortmann (1890) in Western Europe, Zootaxa 3780: 481-502

Seo, Ji Eun (1998) Taxonomy of the marine bryozoans from Namheado Island and its adjacent waters, Korea., Korean Journal of Systematic Zoology 14(4): 415-424

Sloan, N. A., Bartier, P. M. (2004) Introduced marine species in the Haida Gwaii region, British Columbia., Canadian Field-Naturalist 118(1): 77-84

Sorte, Cascade, J. B.; Williams, Susan L.; Zerebecki, Robyn A. (2010) Ocean warming increases threat of invasive species in a marine fouling community, Ecology 91(8): 2198-2204

Soule, Dorothy F.; Soule, John D. (1964) The Ectoprocta (Bryozoa) of Scammon's Lagoon, Baja California, Mexico., American Museum Novitates 2199: 1-56

Soule, Dorothy F.; Soule, John D.; Morris, Penny A.; Chaney, Henry A (2007) The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon (4th edition), University of California Press, Berkeley CA. Pp. 866-904

Sutherland, John P. (1981) The fouling community at Beaufort, North Carolina: a study in stability., American Naturalist 118(4): 499-519

Tompsett, Scott; Porter, Joanne S.; Taylor, Paul D. (2009) Taxonomy of the fouling cheilostome bryozoans Schizoporella unicornis (Johnston) and Schizoporella errata (Waters), Journal of Natural History 43(35-36): 2227-2243

Wasson, Kerstin; Zabin, C. J.; Bedinger, L.; Diaz, M. C.; Pearse J. S. (2001) Biological invasions of estuaries without international shipping: the importance of intraregional transport, Biological Conservation 102: 143-153

Woods Hole Oceanographic Institution, United States Navy Dept. Bureau of Ships (1952) Marine fouling and its prevention., United States Naval Institute., Washington, D.C.. Pp. 165-206

Working Group on Introductions and Transfers of Marine Organisms (WGITMO) (2022) Working Group on Introductions and Transfers of Marine Organisms (WGITMO), ICES Scientific Reports 4(84): 1-209

---