Celleporina porosissima


Scientific Name: Celleporina porosissima

Phylum: Bryozoa

Class: Gymnolaemata

Order: Cheilostomatida

Family: Celleporidae

Genus: Celleporina


porosissima [Describe here as A. iricolor]

Native Distribution

Origin Realm:

Temperate Northern Pacific, Central Indo-Pacific

Native Region:

Origin Location:

Temperate Northern Pacific [Japan] Akkeshi Bay; Oshoro; Hokkaido; Hamada Formation (Grischenko et al 2007; Ikezawa and Mawatari 1993; Hayami 1975) STATUS STATED [Korea] Cheju Island; Yellow Sea; Manjaedo Island; Gampo; Heuksando; Gyeongjeong; Gageodo; Tongyeong; Wido-Island; Boryeong; Yokiljdo; Mijo (Seo 1998; Seo 2000; Seo and Min 2009) STATUS STATED [Korea] All coast of southern Korea. (Seo & Min 2009) STATUS NOT STATED [Japan] Korea Strait. (Okada 1923) STATUS NOT STATED [Japan] Otaru, western shore Oshoro Bay, Hokkaido. (Ikezawa & Mawatari 1993) STATUS NOT STATED [Japan] Akkeshi Bay. (Grischenko et al. 2007) STATUS NOT STATED [Japan] Yokohama, Tokyo Bay. (Hirose 2010) STATUS NOT STATED [Japan] Sagami Bay. (Hirose 2010) STATUS NOT STATED [Japan] Tango Peninsula, Kyoto Prefecture. (Yatsuya et al. 2008) STATUS NOT STATED [Japan] Seto Inland Sea. (Inaba 1988) STATUS NOT STATED [Japan] Wakayama Prefecture. (Nature Conservation Bureau of the Environment Agency 1998) STATUS NOT STATED [Myriozoum marionensis irregulatum (Synonymized taxon)] [Japan] Shimoda, Shizuoka Prefecture. (Okada 1934) STATUS NOT STATED Central Indo-Pacific [Korea] The distribuition of C. p. extends to Indonesia. (Hirose 2010) STATUS NOT STATED Uncertain realm [China] China Seas (Liu 2008, cited in Bock 2015) STATUS NOT STATED

Geographic Range:

[Western Pacific] Japan; Korea; China; Akkeshi Bay, Japan is the northernmost known locality (Seo 1998; Seo 2002; Seo and Min 2009; Grischenko et al 2007) [Japan] Aikappu Cape in Akkeshi Bay: 43°00.4'N, 144°50.1'E. (Grischenko et al. 2007) [Japan] Western shore of Oshoro Bay: 43°12.4'N, 140°51.7'E (Ikezawa & Mawatari 1993) [Japan] Korea Strait: 34°29'N, 130°50'E, 34°17'N, 130°13'E and 34°30'N, 129°51'E. (Okada 1923) [Japan] From 30°N to 35°N both at Pacific side and Japan Sea side. (Inaba 1988)

General Diversity:


Non-native Distribution

Invasion History:

No records of invasion (Global Invasive Species Database 2016)

Non-native Region:

Not applicable

Invasion Propens:

Not applicable

Status Date Non-native:

Not applicable

Vectors and Spread

Initial Vector:

Aquaculture and Fisheries

Second Vector:


Vector Details:

Commonly found in fishing nets (Seo and Min 2009)

Spread Rate:


Date First Observed in Japan:

Fossil records from Japan dating from early Pliocene to Pleistocene (Hayami 1975) CONFLICT: Okada (1923) was apparently the first person to collect this species but described his material from the Korea Strait as a new variety, irregulatum, of Myriozoum marionense Busk 1884 (cited in Grischenko et al 2007)

Date First Observed on West coast North America:



Impact in Japan:


Global Impact:

Fouling species found from fishing nets mostly (Seo and Min 2009)


Native Temperature Regime:

Cold water, Cool temperate, Mild temperate, Warm temperate, Subtropical

Native Temperature Range:

Considered an Asian Pacific Low Boreal-Subtropical species (Grischenko et al 2007) Temperature sampled: 11.614°C (OBIS 2015) [Japan] Akkeshi Bay: The lowest recorded water temperature was -1.4ºC in February 2003, the highest 21.1ºC in August 2004. (Grischenko et al. 2007) Cold water, Cool temperate, Mild temperate, Warm temperate (M. Otani, pers. comm.)

Non-native Temperature Regime:

Not applicable

Non-native Temperature Range:

Not applicable

Native Salinity Regime:

Polyhaline, Euhaline

Native Salinity Range:

Salinity sampled: 34.502 PSU (OBIS 2015) It is said that C. p. is restricted in the intermediate salinity condition between the exposed environment and the estuarine environment in Akkeshi Bay. (Grischenko et al. 2007) Polyhaline (M. Otani, pers. comm.)

Non-native Salinity Regime:

Not applicable

Temperature Regime Survival:

See details

Temperature Range Survival:

Temperature sampled: 11.614°C (OBIS 2015) RELATED: [Celleporina spp.] -0.197 - 26.525 ºC (OBIS 2016)

Temperature Regime Reproduction:


Temperature Range Reproduction:


Salinity Regime Survival:

Euhaline, See details

Salinity Range Survival:

Salinity sampled: 34.502 PSU (OBIS 2015) RELATED: [Celleporina spp.] 27.473 - 36.426 PPS (OBIS 2016)

Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:


Depth Regime:

Supralittoral, Upper intertidal, Mid intertidal, Lower intertidal, Shallow subtidal, Deep subtidal, Bathyal

Depth Range:

Intertidal cheilostome species. Akkeshi Bay: lower intertidal zone (Grischenko et al 2007) Originally collected from depths of 90-200m in the Korea Strait (Grischenko et al 2007) Collected from algae, collected from rocky flat, 0.5m deep (Ikezawa and Mawatari 1993) Collected from depths 18-23m (Seo and Min 2009) Depth sampled at 291m (OBIS 2015) Littoral to sublittoral zone from Hamada Formation forms (Hayami 1975) Sagami Bay: 10-23m. (Hirose 2010) Seto Inland Sea: lower intertidal to 20-30m. (Inaba 1988) Korea Strait: 93-110m. (Okada 1923)

Non-native Salinity Range:

Native Abundance:

Abundant, Common, Few. Rare


Fertilization Mode:


Reproduction Mode:


Spawning Type:


Development Mode:

Lecithotrophic planktonic larva (non-feeding)

Asexual Reproduction:

Budding/fragmentation (Splitting into unequal parts. Buds may form on the body of the “parent”)

Reproduction Details:

Frontal brooding (Ikezawa and Mawatari 1993) RELATED: [Celleporidae] Members of the family Celleporidae...early in their astogeny, zooids in the primary layer begin to bud frontally, becoming buried under the secondary layer of zooids (Ikezawa and Mawatari 1993) [Celleporina] Ooecia budded from the distofrontal wall; 'Kenozooidal ooecia' formed in the genera (Ostrovsky 2013) [Gymnolaemates] Internal fertilization, whether intracoelomic or intraovarian, is obligatory (Temkin 1994 and 1996, cited in Ostrovsky 2013) [Gymnolaemates] Differ from most organisms in that sperm-egg fusion does not stimulate egg activation. Egg activation may not occur until "spawned" outside of maternal zooid (Temkin 1991) [Bryozoans] While sperm is spawned through pores in lophophore tentacles, eggs are usually harbored inside the body wall, and are internally fertilized by sperm, coming in on lophophore feeding currents (Brusca and Brusca 2003, cited in Rouse 2011; Kozloff 1990, cited in Rouse 2011) [Bryozoans] Colonial hermaphrodites, with testes (spermatogenic tissue) and ovaries developing either within the same zooid (zooidal hermaphroditism) or in different zooids within the same colony (zooidal gonochorism) (Ostrovsky 2013) [Bryozoans] Members of the phylum Bryozoa are hermaphroditic. Both fertilization and egg brooding may either be internal or external (Ruppert et al. 2004) [Bryozoans] The first zooid in a colony is called the ancestrula. It is from this individual that the rest of the colony will grow asexually from the budding (Hill 2001) [Bryozoa] All bryozoan colonies are hermaphroditic. Autozooids may be dioecious; or monoecious, and protandrous or protogynous. (Hayward & Ryland 1999) [Bryozoa] Reproduces asexually by budding. (Mawatari 1976)

Adult Mobility:


Adult Mobility Details:

Encrusting species (Grischenko et al 2007) RELATED: [Bryozoa] The abundance and taxonomic diversity of benthic bryozoan faunas are directly related to substratum. (Hayward & Ryland 1999) [Bryozoa] Bryozoans are a phylum of sessile, colonial suspension feeders found throughout the world in both marine and freshwater environments. (Tilbrook 2012)

Maturity Size:

Typical colony measured 1.5 x 1.2 x 0.2 cm; Zooids 0.28-0.38mm across; Primary orifice 0.12-0.18mm long and 0.11-0.16mm wide; Ovicell 0.24-0.33mm long and 0.29-0.39mm wide (Grischenko et al 2007) Non-brooding zooids: Primary oriface: 0.15-0.19mm length, 0.12-0.19mm width Colony: 1.2x1.3x0.15cm; Brooding zooids: Secondary oriface: 0.20-0.24mm length, 0.15-0.22mm width Ovicell: 0.22-0.28mm length, 0.24-0.33width (Ikezawa and Mawatari 1993)

Maturity Age:


Reproduction Lifespan:

There are three separate generations during the year, with peak embryo production during February-March, May-August, and October-November. (Eggleston 1972, cited in Hayward & Ryland 1999)


The life cycle is completed quickly and colonies live for less than a year. (Hayward & Ryland 1999)

Broods per Year:


Reproduction Cues:

RELATED: [Bryozoans] Experiments often used light as a cue to collect embryos/larvae (Woollacott and Zimmer 1977) [Bryozoa] In coastal species light is an important stimulus to larval release, and many cheilostomates shed larvae during the first few hours of daylight. (Hayward & Ryland 1999) [Bryozoa] In various degrees of intensity according to the species temperature also stimulates sexual reproduction. (Winston 1977)

Reproduction Time:

[Japan] Observed populations in June and July all had embryos (Grischenko et al 2007) Embryo presented in all the specimens collected in Akkeshi Bay during the periods 2-7 June and 3-6 July . (Grischenko et al. 2007)



Egg Size:

RELATED: [Gymnolaemata] About 200µm (Woollacott and Zimmer 1977) Ovicell 0.24-0.33mm long and 0.29-0.39mm wide (Grischenko et al 2007

Egg Duration:


Early Life Growth Rate:

RELATED: [Gymnolaemata] Two phases of larvae metamorphosis: first stage about 20mins; second stage 1-6 days (Woollacott and Zimmer 1977)

Adult Growth Rate:


Population Growth Rate:


Population Variablity:




Sediment subtidal, Rocky intertidal, Rocky subtidal, Macroalgal beds, Kelp forest, Fouling

Habitat Type:

Epibenthic, Epiphytic, Epizoic, Other


Sand, Gravel, Cobble, Rock, Biogenic, Artificial substrate


Semi-exposed, Protected

Habitat Expansion:


Habitat Details:

Encountered on rhizoids of Laminaria sp. (Grischenko et al 2007) Occurs most abundantly on Laminaria religiosa but also on various other kinds of substrata from Sargassum spp. and Rhodoglossum spp. to molluscans shells in Oshoro Bay (Ikezawa and Mawatari 1993) Found on stem of seaweed (Seo 1998) Substratum: stones, seaweeds and shells; found from fishing nets mostly (Seo and Min 2009) C. p. was detached from undetermined red algal rhizoid at Aikappu Cape in Akkeshi Bay. (Grischenko et al. 2007) C. p. was found on fronds of Laminaria religiosa in Oshoro Bay. (Ikezawa & Mawatari 1993) C. p. was found on Sargassum autumnale and Myagropsis myagroides at Tango Peninsula, Kyoto Prefecture. (Yatsuya et al. 2008) C. p. was found at the bottom consisted of 100% sand at Korea Strait. (Okada 1923) C. p. was found from stones, seaweeds, shells and fishing nets in Korea. (Seo & Min 2009) Semi-exposed, Protected (M. Otani, pers. comm.)

Trophic Level:

Suspension feeder

Trophic Details:

Is a suspension feeder on phytoplankton (Hughes 1992) RELATED: [Bryozoans] Suspension feeder...filter phytoplankton less than 0.045mm in size from the water column. (Hill 2001) [Bryozoa] Many phytoplankton species are cleary unsuitable as food for bryozoans. (Hayward & Ryland 1999) [Cheilostomata] Main food is diatom, protozoans and etc. and unappropriate sized particles are ejected (Mawatari 1976)

Forage Mode:


Forage Details:

RELATED: [Bryozoans] Suspension feeder...filter phytoplankton less than 0.045mm in size from the water column. (Hill 2001) [Bryozoa] Many phytoplankton species are cleary unsuitable as food for bryozoans. (Hayward & Ryland 1999) [Cheilostomata] Main food is diatom, protozoans and etc. and unappropriate sized particles are ejected (Mawatari 1976)

Natural Control:

RELATED: PREDATION [Predation] [Bryozoa] Browsers and grazers, including sea urchins, fish, crabs and some prosobranchs, are known to include bryozoans in their diet. (Hayward & Ryland 1998) [Predation] [Bryozoa] Bryozoans are also the prey of very many small, selective predators, some of which may be adapted to a very narrow spectrum of prey species. Among them opisthobranch predators of bryozoans are well known. (Hayward & Ryland 1998) [Predation] [Bryozoa] Other than opisthobranchs as a predator, amphipods, isopods, mites and pycnogonids have all been recorded preying on bryozoan colonies. (Hayward & Ryland 1998) EPIBIONTS [Epibionts] [Cheilostomata] It is frequently observed in Japan that several species of hydroids flourish on Cheilostomata cause damages to them. (Mawatari 1976)

Associated Species:


References and Notes


Bock, p. (2015). Celleporina porosissima Harmer, 1957. In: P. Bock & D. Gordon (Eds.). World List of Bryozoa. Retrieved from http://www.marinespecies.org/aphia.php?p=taxdetails&id=469558 Global Invasive Species Database. http://www.iucngisd.org/gisd/ Access Date: 4-Mar-2016. Grischenko, A. V., Dick, M. H., & Mawatari, S. F. (2007). Diversity and taxonomy of intertidal Bryozoa (Cheilostomata) at Akkeshi Bay, Hokkaido, Japan. Journal of Natural History, 41(17-20), 1047-1161. Doi: 10.1080/00222930701391773. Hayami, T. (1975). Neogene Bryozoa from northern Japan. Tohoku Univ., Sci. Rep., 2nd ser. (Geol.), 45(2), 83-126 Hayami, T. (1981). The Pliocene Cheilostomatous Bryozoa from Shikoku on the Pacific Coast of Japan. In G. P. Larwood & C. Nielsen (Eds.), Recent and Fossil Bryozoa: Papers Presented at the 5th International Conference on Bryozoa, Durham, 1980 (pp. 105-112). Fredensborg, Denmark: Olsen&Olsen. Hayward PF & Ryland JS (1999) Cheilostomatous Bryozoa part 2. Hippothooidea - Celleporoidea. Synopses of the British Fauna (New Series). Barnes RSK & Crothers JH (eds.) No. 14 (Second Edition). The Linnean Society of London and The Estuarine and Coastal Sciences Association by Field Studies Council: 416pp. Hill, K. (2001) Smithsonian Marine Station at Fort Pierce. Retrieved from http://www.sms.si.edu/irlspec/Electr_bellul.htm Hirose M (2010) Cheilostomatus Bryozoa (Gymnolaemata) from Sagami Bay, with notes on bryozoan diversity and faunal changes over papst 130 years. Doctoral thesis in Hokkaido University : 1-177pp. Ikezawa, H. & Shunsuke, M. F. (1993). A systematic study of three species of Celleporina (Bryozoa, Cheilostomata) from Hokkaido, Japan with special reference to their early astogeny. Zoological Science, 10(6), 1029-1043. Inaba A (1988) Fauna and Flora of the Seto Inland Sea. Second edition II. Mukaishima Marine Biological Station of Hiroshima University: 1-475. (in Japanese) Mawatari S (1976) Bryozoa (Ectoprocta). In: Animal systematics. Uchida T (ed.) Nakayama-shoten Co. Ltd., Tokyo: 35-229. (in Japanese) Nature Conservation Bureau of the Environment Agency (1998) Report of 5th baseline survey for the nature conservation. Coast line survey. Nature Conservation Bureau of the Environment Agency: 1-957pp. OBIS. Ocean Biogeographic Information System. http://iobis.org/mapper Access date: 08-09-2016 *Note: genus level data Okada Y (1923) On a collection of Bryozoa from the Straits of Corea. Annotationes Zoologicae Japonenses 10: 214-234. Okada Y (1934) Bryozoa founa in the vicinity of the Shimoda Marine Biological Station. Science Reports of the Tokyo Bunrika Daigaku, Section B 2: 1-20. Ostrovsky, A. N. (2013). Evolution of Sexual Reproduction in Marine Invertebrates – Example of gymnolaemate bryozoans. Dordrectht: Springer Netherlands. Doi: 10.1007/978-94-007-7146-8 Rho, B. J., & Seo, J. E. (1986). A systematic study on the marine bryozoans in Cheju-do. Korean Journal of Zoology, 29(1), 31-60. Rouse, S. (2011). Aetea anguina. Bryozoa of the British Isles. Retrieved from http://britishbryozoans.myspecies.info/content/aetea-anguina-linnaeus-1758 Ruppert, E.E., Fox, R.S., and Barnes, R.D. (2004). Invertebrate Zoology: A functional evolutionary approach. Ann Arbor, MN: Thomson Brooks/Cole. Seo, J. E. (1998). Taxonomy of the Marine Bryozoans from Namhaedo Island and Its Adjacent Waters, Korea. The Korean Journal of Systematic Zoology, 14(4), 415-424. Seo, J. E. (2000). New record of two Ascophoran species (Bryozoa, Cheilostomata) from Manjaedo Island, Korea. The Korean Journal of Systematic Zoology, 16(2), 213-218. Seo, J. E. (2002). A new record of Smittinid Bryozoa (Gymnolaemata, Cheilostomata) from Manjae Island, Korea. The Korean Journal of Systematic Zoology, 18(1), 135-141. Seo, J.E. & Min, B. S. (2009). A faunistic study on Cheilostomatous Bryozoans from the shoreline of South Korea, with two new species. The Korean Journal of Systematic Zoology, 25(1), 19-40. Soule, J., Reverter-Gil, O, & De Blauwe, H. (2015). New and little known species of Celleporina Gray, 1848 (Bryozoa, Cheilostomata) from the Atlantic-Mediterranean region. Journal of the Marine Biological Association of the United Kingdom, 95(4), 723-734. Doi: 10.1017/s0025315414001659 Temkin, M. H. (1991). Fertilization in the Gymnolaemate Bryozoa (Doctoral dissertation). Retrieved from ProQuest Dissertations and Theses database. (DP23819). Tilbrook KJ (2012) Cheilostomata: first records of two invasive species in Australia and the northerly range extension for a third. Check List 8: 181-183. http://www.checklist.org.br/getpdf?NGD192-11 Winston JE (1977). Distribution and ecology of estuarine ectoprocts: A critical review. Chesapeake Science, 18: 34‐57. doi:10.2307/1350363. https://fau.digital.flvc.org/islandora/object/fau%3A6214/datastream/OBJ/view/Distribution_and_ecology_of_estuarine_ectoprocts__A_critical_review.pdf Woollacott, R. M., & Zimmer, R. L. (Eds.). (1977). Biology of Bryozoans. New York, NY: Academic Press Yatsuya K, Nishigaki K, Wada Y, Takeno K (2008) Phytal animals in Sargassum beds in coastal areas of Kyoto Prefecture. Bulletin of the Kyoto Institute of Oceanic and Fishery Science 30: 65-70. (in Japanese)


Limited information; expert opinion based on observational information or circumstantial evidence