title: Endemic or introduced? Phylogeography of Asparagopsis (Florideophyceae) in Australia reveals multiple introductions and a new mitochondrial lineage.
abstract: The red seaweed Asparagopsis taxiformis embodies five cryptic mitochondrial lineages (lineage 1-5) introduced worldwide as a consequence of human mediated transport and climate change. We compared globally collected mitochondrial cox2-3 intergenic spacer sequences with sequences produced from multiple Australian locations and South Korea to identify Asparagopsis lineages and to reveal cryptic introductions. We report A. taxiformis lineage 4 from Cocos (Keeling) Islands, Australia, and the highly invasive Indo-Pacific Mediterranean lineage 2 from South Korea and Lord Howe Island, Australia. Phylogeographic analysis showed a clear haplotype and geographic separation between western Australian and Great Barrier Reef (GBR) isolates belonging to the recently described lineage 5. The same lineage, however, was characterized by a substantial genetic and geographic break between the majority of Australian specimens and Asparagopsis collections from South Solitary Island, Southern GBR, Lord Howe Island, Kermadec Islands, Norfolk Island, New Caledonia and French Polynesia. The disjunct geographic distribution and sequence divergence between these two groups supports the recognition of a sixth cryptic A. taxiformis mitochondrial lineage. As climatic changes accelerate the relocation of biota and offer novel niches for colonization, periodic surveys for early detection of cryptic invasive seaweeds will be critical in determining whether eradication or effective containment of the aliens are feasible.
authors.affiliation: Australian Institute of Marine Science, PMB No. 3, Townsville, Queensland, 4810, Australia.|College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, Australia.
authors.forename: Nikos
authors.initials: N
authors.lastname: Andreakis
authors.affiliation: Australian Institute of Marine Science, PMB No. 3, Townsville, Queensland, 4810, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Costello
authors.affiliation: Departamento de Biología Vegetal (Botánica), Universidad de Málaga, Campus de Teatinos s/n, Málaga, 29071, Spain.
authors.forename: Marianela
authors.initials: M
authors.lastname: Zanolla
authors.affiliation: Centre for Environmental and Molecular Algal Research, Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada, E3B 5A3.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Saunders
authors.affiliation: MACRO - the Centre for Macroalgal Resources and Biotechnology, James Cook University, Townsville, Queensland, 4811, Australia.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Mata
mesh_terms: D001315:Australia; D004272:DNA, Mitochondrial; D014644:Genetic Variation; D006239:Haplotypes; D058865:Introduced Species; D008542:Melanesia; D009510:New Caledonia; D010802:Phylogeny; D058974:Phylogeography; D011114:Polynesia; D056910:Republic of Korea; D000461:Rhodophyta / Q000235:genetics / Q000502:physiology*; D012624:Seaweed / Q000235:genetics / Q000502:physiology
chemical_list: D004272:DNA, Mitochondrial
keywords: Asparagopsis; Australia; GBR; cryptic; endemic; invasive; phylogeography