Colonial ascidians of the genus Didemnum are emerging as potent invaders of coastal marine ecosystems. Here, we used taxonomic and phylogenetic approaches to confirm the presence of Didemnum perlucidum in Australia. D. perlucidum is widespread in tropical ports and is thought to be a recent introduction into Brazilian waters, where it has increased biofouling pressure and affected aquaculture practices. D. perlucidum was observed dominating fouling assemblages on settlement panels and jetty pylons at two study sites in the Perth metropolitan area, Western Australia. As identifying members of this genus based on morphological characteristics is difficult, analysis of mtDNA was conducted to verify the occurrence of D. perlucidum in Australia. Space occupation of artificial substrata was observed in summer and autumn, when D. perlucidum colonies overgrew other sessile organisms, including the commercially harvested Blue Mussel (Mytilus edulis ssp. planulatus). This represents the first confirmed record of this species in Australia, which should be considered cryptogenic until detailed biogeographical analyses are conducted. The distribution, biology, and economic and ecological implications of D. perlucidum in Australia are entirely unknown, and warrant urgent investigation.
Ascidian Biofouling Benthic marine communities Didemnids Settlement panels Southwest Australia
This is a preview of subscription content, log in to check access.
We sincerely thank Gretchen Lambert (University of Washington, Friday Harbor Laboratories) for taxonomic expertise, Tim Glasby and Brendon O’ Rourke (Elizabeth Macarthur Agricultural Institute, New South Wales government) for assistance with phylogenetic analysis, and Anne Brearley (University of Western Australia) for insightful discussions and historical perspectives. Christopher Stoddart (University of Western Australia) is also acknowledged for assistance with microscopy and Rosana Rocha (Universidade Federal do Paraná) collected the D. perlucidum specimen from Brazil. DS is funded by the Western Australian Marine Science Institute (WAMSI).
Brearley A (2005) Ernest Hodgkin’s Swanland: estuaries and coastal lagoons of south-western Australia. University of Western Australia Press, Crawley, p 550Google Scholar
Bullard SG (2007) The colonial ascidian Didemnum sp.A: current distribution, basic biology and potential threat to marine communities of the northeast and west coasts of North America. J Exp Mar Biol Ecol 342:99–108CrossRefGoogle Scholar
Chapman JW, Carlton JT (1991) A test of criteria for introduced species: the global invasion by the isopod Synidotea laevidorsalis. J Crustac Biol 11:386–400CrossRefGoogle Scholar
Dijkstra J, Harris LG, Westerman E (2007) Distribution and long-term temporal patterns of four invasive colonial ascidians in the Gulf of Maine. J Exp Mar Biol Ecol 342:61–68CrossRefGoogle Scholar
Grosholz E (2002) Ecological and evolutionary consequences of coastal invasions. Trends Ecol Evol 17:22–27CrossRefGoogle Scholar
Kott P (2001) The Australian ascidiacea part 4, Aplousobranchia (3), Didemnidae. Mem Queensl Mus 47:1–407Google Scholar
Kremer LP, Rocha RM (2011) The role of Didemnum perlucidum F. Monniot, 1983 (Tunicata, Ascidiacea) in a marine fouling community. Aquat Invas 6:441–449CrossRefGoogle Scholar
Kremer LP, Rocha RM, Roper JJ (2010) An experimental test of the colonization ability in the potentially invasive Didemnum perlucidum (Tunicata, Ascidiacea). Biol Invas 12:1581–1590CrossRefGoogle Scholar
Smale DA, Wernberg T, Peck LS, Barnes DKA (2011) Turning on the heat: ecological response to simulated warming in the sea. PLoS ONE 6:e16050PubMedCrossRefGoogle Scholar
Sorte CJB, Stachowicz JJ (2011) Patterns and process of compositional change in a California epibenthic community. Mar Ecol Prog Ser 435:63–74CrossRefGoogle Scholar
Stachowicz JJ, Terwin JR, Whitlatch RB, Osman RW (2002) Linking climate change and biological invasions: ocean warming facilitates nonindigenous species invasions. Proc Natl Acad Sci USA 99:15497–15500PubMedCrossRefGoogle Scholar
Stefaniak L, Lambert G, Gittenberger A, Zhang H, Lin S, Whitlatch RB (2009) Genetic conspecificity of the worldwide populations of Didemnum vexillum Kott, 2002. Aquat Invas 4:29–44CrossRefGoogle Scholar
Thomsen MS, Olden JD, Wernberg T, GJ N, Silliman BR (2011) A broad framework to organize and compare ecological invasion impacts. Environ Res 111:899–908PubMedCrossRefGoogle Scholar
Valentine PC, Carman MR, Blackwood DS, Heffron EJ (2007) Ecological observations on the colonial ascidian Didemnum sp. in a New England tide pool habitat. J Exp Mar Biol Ecol 342:109–121CrossRefGoogle Scholar
Western Australia Planning Commission (2004) Fremantle ports outer harbour project: information brochure. Western Australian Planning Commission, Perth, p 9Google Scholar