Invasion History

First Non-native North American Tidal Record: 1940
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 1940

General Invasion History:

Membraniporopsis tubigerum was first described (as Conopeum tubigerum), from Puerto Rico, Florida, and Texas (Osburn 1940). However, it is now considered to belong to the genus Membraniporopsis, whose other two members are East Asian (Huang 2001; Gordon et al. 2006). It was reported as an introduced species in the Sea of Japan, Russia (as C. tubigerum, Kubanin 1977, cited by Lopez Gappa et al. 2010). We suspect that it will be found growing in waters further south, around China and Japan, and it may be native to the Northwest Pacific, as suggested by Gordon et al. (2006). The preferred habitat of M. tubigerum is unclear - it has been found on fouling plates (Allen 1953) and on algal fronds, but is most often seen in immense drifts washing ashore on sandy beaches (Gordon et al. 2006; Lopez Gappa et al. 2010).

North American Invasion History:

Invasion History on the Gulf Coast:

Osburn described Membraniporopsis tubigerum (as Conopeum tubigerum) using material from Captiva Island, in Charlotte Harbor, Florida (USNM 11851, US National Museum of Natural History 2010, Osburn 1940; Gordon et al. 2006), and from Port Lavaca and Kingsville, Texas, on Matagorda Bay (Osburn 1940. Gordon et al. 2006). We have no recent data on the abundance of this bryozoan in the Gulf of Mexico, but assume that it is still established.

Invasion History Elsewhere in the World:

Osburn described Membraniporopsis tubigerum (as Conopeum tubigerum) using, in part, material from Guanica Harbor, Puerto Rico, dredged in 3 fathoms (~6 m) of water (Osburn 1940).

In the Southwest Atlantic, M. tubigerum was first collected in Itapoá (Santa Catarina State), Brazil, in beach drift (1997, Gordon et al. 2006). It now occurs from La Coronilla, Uruguay north to Itapoá (Espíritu Santo State), Brazil, from 34 to 22°S latitude. In many locations, it has formed large, smelly drifts on beaches (Gordon et al. 2006; Lopez Gappa et al. 2010).

In the Southwest Pacific, M. tubigerum was found on fouling plates in Townsville, Queensland, Australia (Allen 1953), although we have no more recent records. In New Zealand, this bryozoan appeared in large quantities in fish nets and beach drift in 2001 around Kaipara Harbor, North Island, New Zealand. It was very abundant in 2001-2002, but has not been seen in New Zealand since (Gordon et al. 2006).


Membraniporopsis tubigerum initially forms encrusting, circular colonies, but as it grows it produces free, erect, lightly calcified two-layered fronds, which curl and overlap, growing to 60 mm in height and width. The central part of the frond is tapered to the point of attachment, and many branches arise above it. The two layers of zooids on the frond are not arranged back-to-back, but grow somewhat independently of each other. The colonies are pale creamy-white (Gordon et al. 2006).

The ancestrula is subcircular, ~0.26 mm X 0.21 mm in size. The opesia are large, and occupy ~75% of the length of the ancestrula, surrounded by a smooth gymnocyst and a very narrow, smooth cryptocyst. Hooked spines arise from the opercular region, and a pair of zooids are budded distally (Gordon et al. 2006). The periancestrular zooids (budding off around the ancestrula) generally become longer in relation to their width, with increasing distance from the ancestrula. The proximal part of the gymnocyst is reduced as the zooids become more elongated, but the cryptocyst tends to be moderately developed, forming a shelf, usually granular in encrusting zooids, but smooth in erect zooids. Encrusting zooids are 0.34-0.51 mm X 0.12-0.30 mm in size, while erect zooids tend to be longer and narrower (0.36-0.58 mm X 0.15-0.26) (description from Gordon et al. 2006).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Bryozoa
Class:   Gymnolaemata
Order:   Cheilostomata
Suborder:   Anasca
Family:   Flustridae
Genus:   Membraniporopsis
Species:   tubigerum


Conopeum tubigerum (Osburn, 1940)
Membraniporopsis tubigera (Yin and Xia, 1999)

Potentially Misidentified Species



Life History- Membraniporopsis tubigerum colonies start out as encrusting, but become erect colonies composed of many individual zooids (Gordon et al. 2006). The zooids feed by extending the ciliated tentacles of the lophophore as a funnel, creating a current, and driving food particles into their mouths. The food is guided along the tentacles and through the pharynx by the cilia. Larger food particles can be moved or captured by flicking or contracting the tentacles (Barnes 1983). The larval mode of M. tubigerum is unknown. Larvae settle on a substrate and metamorphose into the first zooid of a colony, an ancestrula (Barnes 1983).

Ecology- The preferred habitat of M. tubigerum is unclear- it has been found on fouling plates (Allen 1953) and on algal fronds, but is most often seen in immense drifts washing ashore on sandy beaches, or in large quantities in trawls. However, it has not been found encrusting stones or shells in trawls or on beaches (Gordon et al. 2006; Lopez Gappa et al. 2010).


Phytoplankton, detritus

Trophic Status:

Suspension Feeder



General HabitatUnstructured BottomNone
General HabitatGrass BedNone
General HabitatMarinas & DocksNone
General HabitatRockyNone

Tolerances and Life History Parameters

Broad Temperature RangeNoneWarm-temperate-Tropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

Economic Impacts

Membraniporopsis tubigerum is known for occurring in vast masses on sandy beaches and sandy-muddy bottoms in New Zealand and South America (Uruguay-Brazil), clogging fish nets and washing up in large, smelly masses on recreational beaches (Gordon et al. 2006; Lopez Gappa et al. 2010). These types of impacts have not been reported from US waters of the Gulf of Mexico and Puerto Rico, the type locality of the species.

Fisheries- Large masses of M. tubigerum were reportedly clogging trawl nets used for shrimp-fishing in Brazil and flounder-fishing in New Zealand (Gordon et al. 2006; Lopez Gappa et al. 2010).

Aesthetic- On beaches in Brazil and Uruguay, and in Kaipara Harbour, New Zealand, dense masses of washed up bryozoans interfered with recreation on the beaches (Gordon et al. 2006; Lopez Gappa et al. 2010). Drifts of dead bryozoans were sometimes 50 cm thick, and could line several kilometers of beaches (Lopez Gappa et al. 2010).

Regional Impacts

NZ-IVNoneEconomic ImpactFisheries
Masses of Membraniporopsis tubigerum interfered with flounder fisheries in New Zealand, clogging nets (Gordon et al. 2006).
SA-IINoneEconomic ImpactFisheries
Large masses of Membraniporopsis tubigerum clogged trawl nets, interfering with shrimp fisheries on the Atlantic coast of Uruguay (Lopez Gappa et al. 2010).
NZ-IVNoneEconomic ImpactAesthetic
Membraniporopsis tubigerum formed 'stinking' drifts on beaches in New Zealand (Gordon et al. 2006).
SA-IINoneEconomic ImpactAesthetic
Washed-up masses of Membraniporopsis tubigerum formed 'stinking' drifts on beaches in Uruguay and Brazil, interfering with recreation and tourism. Among the beaches severely affected were Cassino (Rio Grande do Sul, Brazil), and La Coronilla (Uruguay) (Lopez Gappa et al. 2010).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
CAR-IV None 1940 Def Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 1940 Def Estab
G050 Charlotte Harbor 1940 Def Estab
NZ-IV None 2001 Def Unk
G280 Matagorda Bay 1940 Def Estab
G320 Upper Laguna Madre 1940 Def Estab
SA-II None 1997 Def Estab
AUS-XII None 1953 Def Unk
NWP-4a None 1977 Crypto Estab
SA-III None 2002 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Allen, F. E. (1953) Distribution of marine invertebrates by ships, Australian Journal of Marine and Freshwater Research 4(2): 307-316

Barnes, Robert D. (1983) Invertebrate Zoology, Saunders, Philadelphia. Pp. 883

Crivellaro, Marcelo Schuler; Candido, Davi Volney; ilveira, Thiago Cesar Lima; Fonseca, Adriana Carvalhal; Segal, Barbara ´ (2022) A tool for a race against time: Dispersal simulations to support ongoing monitoring program of the invasive coral Tubastraea coccinea, Marine Pollution Bulletin 185(114354): Published online

Gordon, Dennis P.; Ramalho, Laís V.; Taylor, Paul D. (2006) An unreported invasive bryozoan that can affect livelihoods - Membraniporopsis tubigera in New Zealand and Brazil., Bulletin of Marine Science 78(2): 331-341

Gordon, Dennis P.; Hosie, Andrew M.; Carter, Michelle C. (2008) Post-2000 detection of warm-water alien bryozoan species in New Zealand- The significance of recreational vessels, Virginia Museum of Natural History Special Publication 15: 37-48

Huang, Zongguo (Ed.), Junda Lin (Translator) (2001) Marine Species and Their Distributions in China's Seas, Krieger, Malabar, FL. Pp. <missing location>

Kourkoutmani, Polyxeni; Michaloudi, Evangelia (2022) First record of the calanoid copepod Pseudodiaptomus marinus Sato, 1913 in the North Aegean Sea, in Thessaloniki Bay, Greece, None 11(BioInvasions Re): Published online

Liu, X. X.; Yin, X.; Ma, J. (2001) <missing title>, Science Press, Beijing. Pp. 860 p.

Lopez Gappa, Juan; Carranza, Alvar; Gianuca, Norton M.; Scarabino, Fabrizio (2010) Membraniporopsis tubigera, an invasive bryozoan in sandy beaches of southern Brazil and Uruguay, Biological Invasions 12: 977-982

Osburn, Raymond C. (1940) Bryozoa of Porto Rico, N. Y. Academy of Sciences - Scientific Survey of Puerto Rico and the Virgin Islands 16(3): 321-486

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database.

Vieira, Leandro M.; Migotto, Alvaro E.; Winston, Judith E. (2008) Synopsis and annotated checklist of Recent marine Bryozoa from Brazil, Zootaxa 1810: 1-39