Short description of Diadumene lineata, Orange-striped anemone

A small, delicate anemone with a smooth column up to 20 mm in diameter in GB (but larger in its native range). Generally, it is olive green or brown with contrasting orange vertical stripes (less often yellow or white). It has 25-100 slender, smooth tentacles, which are all of one type and usually colourless. Defensive thread-like tentacles (acontia) can extend through pores in the column. When fully extended the top part of the column (capitulum) is distinctly divided from the lower part by a parapet.

Impact summary: Diadumene lineata, Orange-striped anemone

Diadumene lineata is a cosmopolitan invader. Under suitable conditions, it can quickly form large clonal aggregations, which may compete for space and food with native sessile species. This anemone preys mainly on small crustaceans but may also consume larvae of commercially important species such as oysters and mussels.

Habitat summary: Diadumene lineata, Orange-striped anemone

Sheltered estuarine areas, intertidally on hard surfaces including stones, shallowly-buried rocks, shells, seaweeds and on artificial structures as part of the fouling community, often in association with mussels or oysters (Fautin & Hand, 2007; Cohen, 2011). Also in salt marshes associated with Spartina alterniflora (Molina et al., 2009). This species shows extreme physiological tolerances enabling it to colonize areas unsuitable for many fouling species. It can survive for at least two weeks in salinities from 0.5 to 35 ppt, although growth and fission are reduced below 24ppt, and salinities below 7 ppt are ultimately lethal.  It can also withstand temperatures from O C to 27.5 C and long periods of intertidal exposure (Shick & Lamb, 1977; Molina et al., 2009; Podbielski et al., 2016; Ryan & Miller, 2019).

Overview table

Environment	Marine
Species status	Non-Native
Native range	Northwestern Pacific
Functional type	Predator
Status in England	Non-Native
Status in Scotland	Non-Native
Status in Wales	Non-Native
Location of first record	Millbay Docks, Plymouth
Date of first record	1896 1896

Origin

Originally described from Hong Kong (Verrill, 1869) as Sagartia lineata, its native distribution is ascribed to the north-west Pacific including Japan, China and Hong Kong (Uchida ,1932).

First Record

Millbay Docks, Plymouth in 1896 (Walton, 1908).

Pathway and Method

Diadumene lineata has been documented in ship hull fouling (Gollasch & Riemann-Zürneck 1996), and was probably first introduced to Europe via the Suez Canal (Piazzola & Hiebert, 2015). However, other vectors, such as imported oyster cultures, attachment to floating seaweed, and ballast water probably play a role in the global dispersal of this species (Shick & Lamb, 1977; Podbielski et al., 2016).

Species Status

Diadumene lineata has been known by many names, including most recently Haliplanella lineata and Diadumene luciae (Hancock et al., 2017).Established on almost every temperate and tropical coast worldwide, it is believed to be more widespread globally than any other anemone species (Fautin & Hand, 2007). First recorded in N. America, on the Atlantic coast in 1892, by 1978 it had been found as far south as S. Carolina and north to New Brunswick, Canada by 2009. On the Pacific US coast, the first report was from California (1904), and by 1980 it had spread along the entire coast. In S. America it was first observed on the Atlantic coast in Brazil (1977), but was not found on the Pacific coast until 2012 (Chile). There are also records from India (1968), Indonesia (1977), New Zealand (1981), Hawaii (1972), and the Canary Islands (2002).The first European record was from Plymouth in 1896 with further reports from the Mediterranean (1911), Netherlands (1913), and the Baltic Sea (2007) (Uchida, 1932; Dunn, 1982; Carlton et al.,2015; Haussermann et al., 2015; Hancock et al., 2017; Daly & Fautin, 2019).

Dispersal Mechanisms

Potential for natural dispersal in GB is apparently very limited due to the absence of sexual reproduction. The adult grows attached to a solid surface, and is thus potentially liable to rafting on natural or anthropogenic floating substrates.  In its native range, planktonic dispersal of larvae is likely the main mechanism of dispersal.

Reproduction

In its native range D. lineata reproduces sexually as well as asexually (Uchida 1932; Ryan and Miller, 2019). Sexes are separate, the males and females releasing gametes for external fertilization, producing planktonic larvae (Piazzola & Hiebert, 2015).In GB it is presumed that reproduction is fully asexual, as over the past 100 years, no populations with both co-occurring males and females have been reported outside of its native range (Shick & Lamb, 1977; Ting & Geller, 2000). However, Newcomer et al. (2019) have recently discovered a sympatric reproductive male and female population in Coos Bay, Oregon, USA. In the introduced range asexual reproduction is predominantly by longitudinal fission of the column or occasionally pedal laceration, with regrowth of the resulting pieces (Ting & Geller, 2000); fission rate is highly correlated with temperature (Ryan & Miller, 2019). Clonal aggregations with over 4000 individuals per square metre have been reported from the US Atlantic coast (Shick & Lamb, 1977).

Known Predators/Herbivores

In N. America, D. lineata is eaten by the nudibranchs Cuthona perca (McDonald, 2007) and Aeolidia papillosa (Shick & Lamb, 1977).

Resistant Stages

Encystment in thick mucous can occur under extreme conditions of temperature, salinity, desiccation or starvation; D. lineata is perhaps the only anemone capable of this (Carlton, 2003; Cohen, 2011).

Habitat Occupied in GB

This species is usually found in brackish waters such as estuaries, often in marinas and harbours growing on artificial structures such as pontoons and fenders, where it is subject to fluctuating salinities. However, it has also been reported from sheltered natural shores, growing intertidally on rocks, pebbles and other hard substrates, and occasionally from mudflats. There are also a subtidal record from off Anglesey (NBNAtlas, 2019).

Diadumene lineata has been recorded along the south coast of England from West Cornwall to Kent and at the mouth of the R. Severn (NBNAtlas, 2019), with a particularly dense population noted in the Southampton area in 2017 (CW pers. obs).  In Wales, there are scattered reports from Cardiff, Milford Haven, Abereiddy and Anglesey. In Scotland, there are records from Loch Sween on the west coast, Orkney and Shetland.

Environmental Impact

None documented. However where large clonal aggregations form there may be an impact on biochemical fluxes of the benthic ecosystem  competing for space and food with the native benthic hard bottom communities (Podbielski et al., 2016).

Health and Social Impact

None known.

Economic Impact

None documented. However, according to Baker et al. (2004) the anemone might prey on larvae of economically important taxa such as blue mussels and oysters.

Identification

Fautin, D.G., & Hand, C. (2007). Anthozoa, p. 173-184. In: The Light and Smith Manual: intertidal invertebrates from central California to Oregon. J. T. Carlton (ed.). University of California Press, Berkeley.

Hancock, Z.B., Goeke, J.A., & Wicksten, M.K. (2017). A sea anemone of many names: a review of the taxonomy and distribution of the invasive actiniarian Diadumene lineata (Diadumenidae), with records of its reappearance on the Texas coast. ZooKeys, (706), 1.

Piazzola, C.D. & Hiebert, T.C. (2015). Diadumene lineata. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR.

Walton, C.L. (1908). Notes on some Sagartiidae and Zoanthidae from Plymouth. Journal of the Marine Biological Association of the United Kingdom. 8: 207-214.

Biology, ecology, spread, vectors

Carlton, J.T. (2003). Community assembly and historical biogeography in the North Atlantic Ocean: the potential role of human-mediated dispersal vectors. In Migrations and Dispersal of Marine Organisms (pp. 1-8). Springer, Dordrecht.

Carlton, J.T. & Eldredge, L.G. (2015). Update and revisions of the marine bioinvasions of Hawai’i: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago. Lucius G. Eldredge III Memorial Volume: Tribute to a Polymath. Bishop Museum Bulletin in Zoology, 9, 25-47.

Cohen, A.N. (2011). The Exotics Guide: Non-native Marine Species of the North American Pacific Coast. Center for Research on Aquatic Bioinvasions, Richmond, CA, and San Francisco Estuary Institute, Oakland, CA. Revised September 2011. http://www.exoticsguide.org

Daly, M. & Fautin, D. (2019). World List of Actiniaria. Diadumene lineata (Verrill, 1869). Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=395099 on 2019-07-25

Dunn, D.F. (1982). Sexual reproduction of two intertidal sea anemones (Coelenterata: Actiniaria) in Malaysia. Biotropica, 262-271.

Fautin, D.G., & Hand, C. (2007). Anthozoa, p. 173-184. In: The Light and Smith Manual: intertidal invertebrates from central California to Oregon. J. T. Carlton (ed.). University of California Press, Berkeley.

Gollasch, S., & Riemann-Zürneck, K. (1996). Transoceanic dispersal of benthic macrofauna: Haliplanella luciae (Verrill, 1898)(Anthozoa, Actiniaria) found on a ship's hull in a shipyard dock in Hamburg Harbour, Germany. Helgoländer Meeresuntersuchungen, 50(2), 253.

Hancock, Z.B., Goeke, J.A., & Wicksten, M.K. (2017). A sea anemone of many names: a review of the taxonomy and distribution of the invasive actiniarian Diadumene lineata (Diadumenidae), with records of its reappearance on the Texas coast. ZooKeys, (706), 1.

Häussermann, V., Spano, C., Thiel, M., & Lohrmann, K.B. (2015). First record of the sea anemone Diadumene lineata (Verrill, 1869) from the Chilean coast. Spixiana, 38(1), 39-42.

McDonald, G.R. (2007). Sacoglossa and Nudibranchia, p. 788-807. In: The Light and Smith manual: intertidal invertebrates from central California to Oregon. J. T. Carlton (ed.). University of California Press, Berkeley, CA.

Molina, L.M., Valiñas, M.S., Pratolongo, P.D., Elias, R., &Perillo, G.M. (2009). First record of the sea anemone Diadumene lineata (Verrill 1871) associated to Spartina alterniflora roots and stems, in marshes at the Bahia Blanca estuary, Argentina. Biological Invasions, 11(2), 409-416.

NBN Atlas (2019). Website at http://species.nbnatlas.org/species/NHMSYS0020770700 Accessed 28 August 2019.

Newcomer, K., Flenniken, M.M., & Carlton, J.T. (2019). Home and away and home again: discovery of a native reproductive strategy of the globally invading sea anemone Diadumene lineata (Verrill, 1869) in a satellite population. Biological Invasions, 21(5), 1491-1497.

Podbielski, I., Bock, C., Lenz, M., & Melzner, F. (2016). Using the critical salinity (S crit) concept to predict invasion potential of the anemone Diadumene lineata in the Baltic Sea. Marine Biology, 163(11), 227.

Ryan, W.H., & Miller, T.E. (2019). Reproductive strategy changes across latitude in a clonal sea anemone. Marine Ecology Progress Series, 611, 129-141.

Shick, J.M., & Lamb, A.N. (1977). Asexual reproduction and genetic population structure in the colonizing sea anemone Haliplanella luciae. The Biological Bulletin, 153(3), 604-617.

Ting, J.H., & Geller, J.B. (2000). Clonal diversity in introduced populations of an Asian sea anemone in North America. Biological Invasions, 2(1), 23-32.

Uchida, T. (1932). Occurrence in Japan of Diadumene luciae, a remarkable Actinian of rapid dispersal.Journal of the Faculty of Science, Hokkaido Imperial University, Series IV 2: 69–84.

Management and impact

Baker, P., Baker, S.M. & Fajans, J. (2004). Nonindigenous marine species in the greater Tampa Bay ecosystem. Tampa Bay Estuary Program Tech. Publ, (02–04.

Podbielski, I., Bock, C., Lenz, M., & Melzner, F. (2016). Using the critical salinity (S crit) concept to predict invasion potential of the anemone Diadumene lineata in the Baltic Sea. Marine Biology, 163(11), 227.

General

Cohen, A.N. (2011). The Exotics Guide: Non-native Marine Species of the North American Pacific Coast. Center for Research on Aquatic Bioinvasions, Richmond, CA, and San Francisco Estuary Institute, Oakland, CA. Revised September 2011. http://www.exoticsguide.org

Fofonoff, P.W., Ruiz, G.M., Steves, B., Simkanin, C., & Carlton, J.T. (2018). National Exotic Marine and Estuarine Species Information System. http://invasions.si.edu/nemesis/. Access Date: 29-Aug -2019

Piazzola, C.D. & T.C. Hiebert. (2015). Diadumene lineata. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR.