Celleporina umbonata


Scientific Name: Celleporina umbonata

Phylum: Bryozoa

Class: Gymnolaemata

Order: Cheilostomatida

Family: Celleporidae

Genus: Celleporina


umbonata [Describe here as A. iricolor]

Native Distribution

Origin Realm:

Temperate Northern Pacific

Native Region:

Origin Location:

Temperate Northern Pacific [Japan] Muroran, Hokkaido. (Ikezawa & Mawatari 1993) HOLOTYPE [Japan] Hokkaido (Ikezawa and Mawatari 1993 STATUS STATED [Japan] Along the coast of Ibaraki Prefecture. (Inoue et al. 2010) STATUS NOT STATED [Japan] Sagami Bay. (Hirose 2010) STATUS NOT STATED

Geographic Range:

[Western Pacific] Japan (Ikezawa and Mawatari 1993) Denshin-Hama, Muroran, Hokkaido: 42°18.6'N, 140°58.3'E. (Ikezawa & Mawatari 1993)

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:


Second Vector:


Vector Details:


Spread Rate:


Date First Observed in Japan:

New species, first collected by Ikezawa in 1991 (Ikezawa and Mawatari 1993)

Date First Observed on West coast North America:



Impact in Japan:


Global Impact:



Native Temperature Regime:

Mild temperate

Native Temperature Range:

[Japan] Muroran, Hokkaido of north Japan: max 18.0ºC in summer and min 2.0ºC in winter. (Clark et al. 2003) [Japan] Kashima, Ibaraki Prefecture: max 25.0ºC in summer and min 8.0ºC in winter. (Clark et al. 2003) Mild 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:

[Japan] Muroran, Hokkaido in north Japan: max 32.0psu in dry period and min 23.0psu in wet period. (Clark et al. 2003) [Japan] Kashima, Ibaraki Prefecture: max 34.0psu in dry period and min 29.0psu in wet period. (Clark et al. 2003)

Non-native Salinity Regime:

Not applicable

Temperature Regime Survival:

See details

Temperature Range Survival:

RELATED: [Celleporina spp.] -0.197 - 26.525 ºC (OBIS 2016)

Temperature Regime Reproduction:


Temperature Range Reproduction:


Salinity Regime Survival:

Polyhaline, Euhaline

Salinity Range Survival:

RELATED: [Celleporina spp.] 27.473 - 36.426 PPS (OBIS 2016)

Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:


Depth Regime:

Lower intertidal, Shallow subtidal, See details

Depth Range:

Considered as intertidal species (Ikezawa and Mawatari 1993) Collected from rocky flat, 50cm deep (Ikezawa and Mawatari 1993) C. u. were collected at the intertidal zone at both Muroran and the coast of Ibaraki Prefecture, but tidal height is unknown. (See Ikezawa & Mawatari 1993, Inoue et al. 2010)

Non-native Salinity Range:

Native Abundance:



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 budding (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 (Ikezawa and Mawatari 1993) 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:

Non brooding zooids: Primary orifice: 0.14-0.18mm length, 0.11-0.14mm width Brooding zooids: Secondary orifice: 0.17-0.22mm length, 0.15-0.16mm width; ovicell: 0.18-0.25mm length, 0.24-0.30mm width (Ikezawa and Mawatari 1993) Colony encrusting, 0.5x0.7x0.1cm (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:

Matured colonies were collected at May, June, and July in 1991 including immature colonies in June and July in the same year. (Ikezawa & Mawatari 1993)



Egg Size:

RELATED: [Gymnolaemata] About 200µm (Woollacott and Zimmer 1977) Ovicell: 0.18-0.25mm length, 0.24-0.30mm width (Ikezawa and Mawatari 1993)

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:




Rocky intertidal, Rocky subtidal, Macroalgal beds

Habitat Type:

Epibenthic, Epiphytic


Rock, Biogenic, Artificial substrate, Other


Exposed, Semi-exposed

Habitat Expansion:


Habitat Details:

Collected on a leaf of Rhodoglossum japonicum and Chondrus yendoi (Ikezawa and Mawatari 1993) Collected from rocky flats near Oshoro Marine Biological Station (Ikezawa and Mawatari 1993) Colonies of C. u. were found on a leaf of Rhodoglossum japonicum from the intertidal reef-flat at Denshin-Hama, Muroran, Hokkaido. (Ikezawa & Mawatari 1993) Artificial substrate, Other substrate, Exposed, Semi-exposed (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


Clarke C, Hillard R, Junqueira AOR, Neto ACL, Polglaze J, Raaymakers S (2003) Ballast water risk assessment, Port of Sepetiba, Fedral Republic of Brazil. GloBallast Monograph Series 14: 1-63 + 7 Appendices. Global Invasive Species Database. http://www.iucngisd.org/gisd/ Access Date: 4-Mar-2016. 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. Inoue H, Kamogawa M, Takashio O, Higano H, Namikawa H, Tanaka H, Saito S, Ikezawa H, Morino H (2010) Fauna of marine invertebrates from the headland on the Kashimanada Coast and the middle coast of Ibaraki Prefecture. Report of comprehensive surveys of plants, animals and geology in Ibaraki Prefecture by the Ibaraki Nature Museum. Ibaraki Nature Museum: 1-35pp. (in Japanese) https://www.nat.museum.ibk.ed.jp/pdf/publications/3/10/marine10.pdf Mawatari S (1976) Bryozoa (Ectoprocta). In: Animal systematics. Uchida T (ed.) Nakayama-shoten Co. Ltd., Tokyo: 35-229. (in Japanese) 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 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. 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