Cryptosula zavjalovensis


Scientific Name: Cryptosula zavjalovensis

Phylum: Bryozoa

Class: Gymnolaemata

Order: Cheilostomatida

Family: Cryptosulidae

Genus: Cryptosula


zavjalovensis [Describe here as A. iricolor]

Native Distribution

Origin Realm:

Arctic, Temperate Northern Pacific

Native Region:

Origin Location:

Arctic Bering Sea (Ruiz 2006; Grischenko 2002; Dick et al 2005) STATUS STATED Temperate Northern Pacific [US] Alaska; Narrow Strait; Kodiak Islands; Gulf of Alaska; Higgins Point (Ruiz 2006; Grischenko 2002; Dick et al 2005) STATUS STATED [Japan] Akkeshi Bay, Hokkaido; Nakholdka Bay; Sea of Japan (Grischenko et al 2007; Kashin et al 2003; Mawatari and Mawatari 1981) STATUS NOT STATED [Russia] Gulf of Anadyr; Commander Islands; Kamchatka; Sea of Japan (Grischenko 1997, 2004, cited in Dick et al 2005; Kubanin 1997; Grischenko et al 2007) STATUS NOT STATED [Cryptosula okadai (Synonymized taxon)] Port Etches, Zaikof Bay, Squirrel Bay, and Anchor Cove in the northern Gulf of Alaska. (Dick & Ross 1988) STATUS NOT STATED [Cryptosula okadai (Synonymized taxon)] Midarm Island and Shartin Bay in the Kodiak archipelago and Dutch Harbor in the eastern Aleutian Islands. STATUS NOT STATED [Cryptosula okadai (Synonymized taxon)] [Japan] Mutsu Bay. (Okada 1929) STATUS NOT STATED [Lipraria reticulata, Eurystomella reticulata or present name] Gulf Anadyr, Kamchatka, Commander Islands, Sea of Okhotsk, Kuril Islands, Sakhalin Island, Primorye, and northern sector of the Sea of Japan. (Adnrosova 1958, etc., cited in Grischenko et al. 2007) STATUS NOT STATED [Lipraria reticulata, Eurystomella reticulata or present name] [Japan] Shirikishinai, southern Hokkaido. (Mawatari & Mawatari 1981) STATUS NOT STATED Uncertain realm [US] Alaska (Ruiz 2006; Grischenko 2002; Dick et al 2005) STATUS STATED

Geographic Range:

[Western Pacific] Bering Sea; Russia to Japan (Grischenko 1997, 2004, cited in Dick et al 2005; Kubanin 1997; Grischenko et al 2007; Okada 1929, cited in Dick et al 2005) [Eastern Pacific] Ketchikan, northern Gulf of Alaska, Kodiak Island, eastern Aleutian Islands, and Bering Sea (O'Donoghue 1925 and Dick and Ross 1988, cited in Dick et al 2005)

General Diversity:

Cryptosula okadai considered a junior synonym of Cryptosula zavjalovensis (Grischenko 2002)

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:

Not applicable

Date First Observed in Japan:

Mawatari and Mawatari described the species in 1981, based on their collection of bryozoans at Hokkaido prior to 1973 (Mawatari and Mawatari 1981)

Date First Observed on West coast North America:

Conducted Alaskan surveys in 2003 (Dick et al 2005)


Impact in Japan:


Global Impact:



Native Temperature Regime:

Cold water, Cool temperate

Native Temperature Range:

Wide Boreal Pacific species (Grischenko et al 2007) [United States] Anchorage, near Port Etches: max 12.0ºC in summer and min -1.0ºC in winter. (Clark et al. 2003) [Japan] Muroran, Hokkaido near Shirikishinai: max 18.0ºC in summer and min 2.0ºC in winter. (Clark et al. 2003) Cold water, Cool 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)

Non-native Salinity Regime:

Not applicable

Temperature Regime Survival:

See details

Temperature Range Survival:

RELATED: [Cryptosula spp.] 6.894 - 16.565ºC (OBIS 2016)

Temperature Regime Reproduction:


Temperature Range Reproduction:


Salinity Regime Survival:

See details

Salinity Range Survival:

RELATED: [Cryptosula spp.] 18.330 - 39.053 PPS (OBIS 2016)

Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:


Depth Regime:

Mid intertidal, Lower intertidal, Shallow subtidal, Deep subtidal

Depth Range:

Mid-intertidal zone to a depth of at least 40m (Androsova 1958, cited in Dick et al. 2005) Intertidal species (Grischenko et al. 2007) North Pacific Rim: mid-intertidal zone to a depth about 40m (Androsova 1958, cited in Grischenko et al. 2007)

Non-native Salinity Range:

Native Abundance:

Rare, Common, Abundant


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:

Lacking ovicells, embryos brooded internally (Dick et al 2005) RELATED: [Cryptosula] Same genus as Cryptosula pallasiana. Described as lecithotrophic larvae and budding (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:

Found on boulders, encrusted on algae (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:

Longer zooids: 0.70-1.33 mm x 0.30-0.58mm; Shorter zooids: 0.58-0.68mm x 0.30-0.45mm (Dick et al 2005) Found a damaged colony 2cm across (Dick et al 2005)

Maturity Age:


Reproduction Lifespan:




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] Embryos observed in colonies during collection periods in June and July (Grischenko et al 2007)



Egg Size:

RELATED: [Gymnolaemata] About 200µm (Woollacott and Zimmer 1977)

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, Kelp forest, Macroalgal bed, Fouling

Habitat Type:

Epibenthic, Epiphytic, Epizoic, Under rock


Rock, Biogenic, Hardpan, Artificial substrate


Semi-exposed, Protected

Habitat Expansion:


Habitat Details:

Found encrusting Laminiaria spp.; found in density or cover, on undersides of boulders; also found on concrete, plastic debris (Grischenko et al 2007) One of few species observed on the upper surface of stable boulders (Grischenko et al 2007) Found on Laminaria japonica and C. costata assemblages (Kashin et al 2003) C. z. is found on rock, concrete, and plastic debris at Akkeshi Bay (Grischenko et al. 2007) and on coral and shells at Mutsu Bay (Okada 1929). Protected, Epizoic (M. Otani, pers. comm.)

Trophic Level:

Suspension feeder

Trophic Details:

RELATED: All bryozoans, is a 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. Dick, M. H., Grischenko, A. V., & Mawatari, S. F. (2005). Intertidal Bryozoa (Cheilostomata) of Ketchikan, Alaska. Journal of Natural History, 39(43), 3687-3784. Doi: 10.1080/00222930500415195 Dick MH & Ross JRP (1988) Intertidal Bryozoa (Cheilostomata) of the Kodiak vicinity, Alaska. Center for Pacific Northwest Studies Western Washington University, Occasional paper 23: 1-133. Global Invasive Species Database. Access Date: 8-Mar-2016. Grischenko, A. V. (2002). History of investigations and current state of knowledge of bryozoans species diversity in the Bring Sea. In P. N. W. Jackson & M. E. S. Jones (Eds.). Annals of Bryozoology: Aspects of the History of Research on Bryozoans (pp. 97-116). Dublin, UK: International Bryozoology Association. 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. 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 Kashin, I. A., Bagaveeva, E. V., & Chaplygina, S. F. (2003). Fouling communities of hydrotechnical constructions in Nakhodka Bay (Sea of Japan). Russian Journal of Marine Biology, 29(5), 267-283. Mawatari S (1976) Bryozoa (Ectoprocta). In: Animal systematics. Uchida T (ed.) Nakayama-shoten Co. Ltd., Tokyo: 35-229. (in Japanese) Mawatari SF & Mawatari S (1981) A preliminary list of cheilostomatous bryozoans collected along the coast of Hokkaido. Proceedings of the Japanese Society of Systematic Zoology 21: 41-58. OBIS. Ocean Biogeographic Information System. Access date: 09-09-2016 *Note: genus level data Okada Y (1929) Report of the biological survey of Mutsu Bay. 12. Cheilostomatous Bryozoa of Mutsu Bay. Science Report of the Tohoku Imperial University, Ser. 4, 4: 11-35. 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 Ruiz, G. M., Huber, T., Larson, K., McCann, L., Steves, B., Fofonoff, P., & Hines, A. H. (2006). Biological Invasions in Alaska’s Coastal Marine Ecosystems: Establishing a Baseline. Retrieved from University of Alaska Fairbanks website: 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. Winston JE (1977). Distribution and ecology of estuarine ectoprocts: A critical review. Chesapeake Science, 18: 34‐57. doi:10.2307/1350363. Woollacott, R. M., & Zimmer, R. L. (Eds.). (1977). Biology of Bryozoans. New York, NY: Academic Press


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