Membranipora raymondi


Scientific Name: Membranipora raymondi

Phylum: Bryozoa

Class: Gymnolaemata

Order: Cheilostomatida

Family: Membraniporidae

Genus: Membranipora


raymondi [Describe here as A. iricolor]

Native Distribution

Origin Realm:

Temperate Northern Pacific

Native Region:

Origin Location:

Temperate Northern Pacific [Japan] fossil records from northern Japan (Hayami 1975) STATUS STATED [USA] California (Hayami 1975) STATUS NOT STATED Not recent: from the Pliocene Shibikawa Formation at Anden, Oga City, Akita Prefecture. (Hayami 1975) STATUS NOT STATED [Membranipora fusca (Synonymized taxon)] Mussel Point, Del Monte, and Tomales Bay in California. (Osburn 1950) STATUS NOT STATED

Geographic Range:

[Western Pacific] Japan (Hayami 1975) [Eastern Pacific] California, US (Hayami 1975) [Membranipora fusca (Synonymized taxon)] [California] Mussel Point: 36°37'20"N, 121°54'15"W; Del Monte: 36°37'00"N, 121°53'00"W. (Osburn 1950)

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:

Fossil records of the species from late Pliocene to early Pleistocene (Hayami 1975)

Date First Observed on West coast North America:



Impact in Japan:


Global Impact:



Native Temperature Regime:

Mild temperate

Native Temperature Range:

Mild temperate (M. Otani, pers. comm.)

Non-native Temperature Regime:

Not applicable

Non-native Temperature Range:

Not applicable

Native Salinity Regime:

See details

Native Salinity Range:

RELATED: [Membranipora] Although Membranipora is a euryhaline genus, it is found in mesohaline water, namely 3-16psu (Borg 1931, cited in Hayami 1975). In water of more than 40psu, Membranipora has been reported living in the Suez Canal. (Cheetham 1963, cited in Hayami 1975) [Cribrilina, Membranipora, Hippoporina, Schizoporella, Smittina and related genera] Supported by polyhaline water. Although Membranipora is a euryhaline genus, it is found in mesohaline water, namely 3-16%o. In water of more than 40% salinity, Bugula, Holoporella [=Celleporaria], Membranipora, Schizoporella, Scrupocellaria, Smittina and Watersipora [=Dakaria] have been reported living in the Suez Canal. (Hayami 1975)

Non-native Salinity Regime:

Not applicable

Temperature Regime Survival:

Cool temperate, Mild temperate, Warm temperate, Subtropical, Tropical

Temperature Range Survival:

True eurythermal genera, occurring in shallow water in tropical as well as in boreal and antiboreal regions (Cheetham 1963, cited in Hayami 1975)

Temperature Regime Reproduction:


Temperature Range Reproduction:


Salinity Regime Survival:

Mesohaline, Polyhaline, Euhaline

Salinity Range Survival:

RELATED: [Membranipora] Supported by polyhaline and euryhaline water; also found in mesohaline water, namely 3-16%o (Borg 1930 and Hutchins 1945, cited in Hayami 1975; Borg 1931, cited in Hayami 1975)

Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:


Depth Regime:

Lower intertidal, Shallow subtidal

Depth Range:

intertidal to 6 fms (10.8m) (Osburn 1950, cited in Hayami 1975) Del Monte California: Intertidal to 6 fms at Del Monte. (Osburn 1950) Tomale Bay, California: 5 fms. (Osburn 1950)

Non-native Salinity Range:

Native Abundance:



Fertilization Mode:


Reproduction Mode:


Spawning Type:


Development Mode:

Planktotrophic planktonic larva (feeding)

Asexual Reproduction:

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

Reproduction Details:

RELATED: [Membranipora] Studies on Membranipora membranacea shows that it has planktotrophic developmental pattern (Temkin 1991) [Membraniporidea] Shed numerous small eggs directly to the sea (Hayward & Ryland 1998) and fetilize in the sea. (Mawatari 1976) These develop into shelled, planktorophic larvae, termed cyphonautes, which feed and grow during several weeks or months spent in the plankton. (Hayward & Ryland 1998) [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] Non-brooding bryozoans feed during the larval stage, while the larvae of brooding bryozoans do not, since these larvae tend to settle soon after release (Hill 2001) [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) CONFLICT For many Gymnolaemate bryozoa, eggs are not activated when fused with sperm at internal site. Instead, egg must be broadcasted before egg activation takes place. In this way, Membranipora spp. is described as being broadcasters despite fertilization being internal process (Temkin 1991; Ostrovsky 2013)

Adult Mobility:


Adult Mobility Details:

RELATED: [Bryozoa] The abundance and taxonomic diversity of benthic bryozoan faunas are directly related to substratum. (Hayward & Ryland 1998) [Bryozoa] Bryozoan colonies are sessile (Hayami 1975) [Bryozoa] Bryozoans are a phylum of sessile, colonial suspension feeders found throughout the world in both marine and freshwater environments. (Tilbrook 2012)

Maturity Size:

Zooecia = 0.64-0.72mm (Hayami 1975)

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:




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:





Habitat Type:





Exposed, Semi-exposed

Habitat Expansion:


Habitat Details:

Found admixed in shell bed (Haymai 1975) Exposed, Semi-exposed (M. Otani, pers. comm.)

Trophic Level:

Suspension feeder

Trophic 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)

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: 15-Mar-2016. Hayami, T. (1975). Neogene Bryozoa from northern Japan. Tohoku Univ., Sci. Rep., 2nd ser. (Geol.), 45(2), 83-126. 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) Osburn RC (1950) Bryozoa of the Pacific coast of America. Part 1. Cheilostomata - Anasca. The University of Southern California Publication. Allan Hancock Pacific Expedition 14: 1-269. 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 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


Little or no information; expert opinion based on general knowledge