Cauloramphus cryptoarmatus


Scientific Name: Cauloramphus cryptoarmatus

Phylum: Bryozoa

Class: Gymnolaemata

Order: Cheilostomatida

Family: Calloporidae

Genus: Cauloramphus


cryptoarmatus [Describe here as A. iricolor]

Native Distribution

Origin Realm:

Temperate Northern Pacific

Native Region:

Origin Location:

Temperate Northern Pacific [Japan] Akkeshi Bay; Hokkaido (Grischenko et al. 2007; Okada et al. 2008) STATUS NOT STATED [Japan] Akkeshi Bay (Grischenko et al. 2007) STATUS NOT STATED [Soebetsu River, Japan] identified as species present in river stratum but uncertain (Okada et al. 2008) STATUS NOT STATED

Geographic Range:

[Western Pacific] Restricted to Japan near Akkeshi Bay (Grischenko et al 2007) [Japan] Aininkappu Cape in Akkeshi Bay: 42°59.6'N, 144°51.3'E. (Grischenko et al. 2007)

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:

[Akkeshi Bay, Japan] June 2-7/July 3-6, 2004 (Grischenko et al. 2007)

Date First Observed on West coast North America:



Impact in Japan:


Global Impact:



Native Temperature Regime:

Cold water, See details

Native Temperature Range:

[Akkeshi Bay, Japan] The lowest recorded water temperature in Akkeshi Bay was -1.4°C in February 2003, the highest 21.1°C in August 2004 (Grischenko et al. 2007) Cold water (M. Otani, pers. comm.)

Non-native Temperature Regime:

Not applicable

Non-native Temperature Range:

Not applicable

Native Salinity Regime:

Polyhaline, Euhaline

Native Salinity Range:

[Akkeshi Bay, Japan] Salinity is relatively constant, about 30 PSU, it ranged from 26 PSU in June 2003 to 31 PSU in August 2004 (Nakamura et al. 2005, cited in Grischenko et al. 2007) It is also said that C. c. is tolerant of conditions ranging from near-oceanic to estuarine. (Grischenko et al. 2007)

Non-native Salinity Regime:

Not applicable

Temperature Regime Survival:

See details

Temperature Range Survival:

RELATED: [Cauloramphus spp.] -0.853 - 12.552 ºC (OBIS 2016)

Temperature Regime Reproduction:


Temperature Range Reproduction:


Salinity Regime Survival:


Salinity Range Survival:

RELATED: [Cauloramphus spp.] 31.235 - 34.925 PPS (OBIS 2016)

Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:


Depth Regime:

Lower intertidal, Shallow subtidal, Deep subtidal, Bathyal, Abyssal

Depth Range:

[Akkeshi Bay, Japan] Specimens were collected intertidally (Ostrovsky et al. 2007) Sampled from 0 - 2410 m depth (OBIS 2016) [Japan] Aininkappu Cape in Akkeshi Bay: -0.1m mean lower low water. (Grischenko et al. 2007)

Non-native Salinity Range:

Native Abundance:

Few, See detail


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:

Strongly reduced ooecium evident externally and a sac in the coelomic cavity of the maternal zooid that functions for the brooding of embryos (Ostrovsky et al. 2007) Mature oocytes were positioned laterally either in the middle or proximal part of the zooid; embryos were brooded inside the internal brood sac in the distal half of the maternal autozooid (Ostrovsky et al. 2007) Macrolecithal oogenis, brooding, lecithotrophy (Pattern II reproductive pattern) (Ostrovsky et al. 2009) Consecutive embryonic incubation of a few large macrolecithal oocytes (relatively large yolk) without extra embryonic nutrition in the brood chamber (Ostrovsky et al. 2009) RELATED: [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 1998) [Bryozoa] Reproduces asexually by budding. (Mawatari 1976)

Adult Mobility:


Adult Mobility Details:

Colony encrusting (Grischenko et al. 2007) RELATED: [Bryozoa] The abundance and taxonomic diversity of benthic bryozoan faunas are directly related to substratum. (Hayward & Ryland 1998) [Bryozoa] Bryozoans are a phylum of sessile, colonial suspension feeders found throughout the world in both marine and freshwater environments. (Tilbrook 2012)

Maturity Size:

Zooids: 0.52-73mm long, 0.30-40mm wide (Grischenko et al. 2007) Opesia: 0.32-0.40mm long; 0.17-0.27mm wide, occupying 60-75% of zooidal length (Grischenko et al. 2007) Ancestrula: 0.28mm long, 0.20mm wide (Grischenko et al. 2007)

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 1998) [Bryozoa] In various degrees of intensity according to the species temperature also stimulates sexual reproduction. (Winston 1977)

Reproduction Time:

[Akkeshi Bay, Japan] Embryos were observed during collection periods 2-7 June and 3-6 July 2004 (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, Other

Habitat Type:

Epibenthic, Epizoic


Rock, Biogenic



Habitat Expansion:


Habitat Details:

[Akkeshi Bay, Japan] Rock (94%), shell (4.8%), Phidolopora elongata (1.2%)(Grishenko et al. 2007) [Japan] Many are on rocks, some are on shells and a few are on Phidolopora elongata at Aninkappu Cape in Akkeshi Bay. (Grischenko et al. 2007) Semi-exposed (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 1998) [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 1998) [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


Global Invasive Species Database. Access Date: 2-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(14-20), 107-1161. Doi: 10.1080/00222930701391773 Hayward PF & Ryland JS (1998) Cheilostomatous Bryozoa part I. Aeteoidea - Cribrilinoidea. Synopses of the British Fauna (New Series). Barnes RSK & Crothers JH (eds.) No. 10 (Second Edition). The Linnean Society of London and The Estuarine and Coastal Sciences Association by Field Studies Council: 366pp. Hill, K. (2001). Smithsonian Marine Station at Fort Pierce. Retrieved from Mawatari S (1976) Bryozoa (Ectoprocta). In: Animal systematics. Uchida T (ed.) Nakayama-shoten Co. Ltd., Tokyo: 35-229. (in Japanese) OBIS. Ocean Biogeographic Information System. Access date: 06-09-2016 *Note: genus level data Okada, H., Mawatari, S.F., Suzuki, N., & Gautam, P. (Eds.). Origin and Evolution of Natural Diversity, Proceedings of International Symposium “The Origin and Evolution of Natural Diversity” (pp. 93-99). Hokkaido, JP: 21st Century COE for Neo-Science of Natural History. 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 Ostrovsky, A. N., Dick, M. H., & Mawatari, S. F. (2007). The Internal-Brooding Apparatus in the Bryozoan Genus Cauloramphus (Cheilostomata: Calloporidae) and Its Inferred Homology to Ovicells. Zoological Society of Japan, 24(12), 1187-1196. Doi: 10.2108/zsj.24.1187 Ostrovsky, A.N., Gordon, D. P., & Lidgard, S. (2009). Independent evolution of matrotrophy in the major classes of Bryozoa: transitions among reproductive patterns and their ecological background. Marine Ecology Progress Series, 378, 113-124. Doi: 10.3354/meps07850 Rouse, S. (2011). Aetea anguina. Bryozoa of the British Isles. Retrieved from Ruppert, E.E., Fox, R.S., & 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


Little or no information; expert opinion based on general knowledge