The invasive genus Asparagopsis (Bonnemaisoniaceae, Rhodophyta): Molecular systematics, morphology, and ecophysiology of Falkenbergia isolates

Authors: Ní Chualáin, F., Maggs, C.A., Saunders, G.W. and Guiry, M.D.

Journal: Journal of Phycology

Volume: 40

Issue: 6

Pages: 1112-1126

ISSN: 0022-3646

DOI: 10.1111/j.1529-8817.2004.03135.x

Abstract:

The genus Asparagopsis was studied using 25 Falkenbergia tetrasporophyte strains collected worldwide. Plastid (cp) DNA RFLP revealed three groups of isolates, which differed in their small subunit rRNA gene sequences, temperature responses, and tetrasporophytic morphology (cell sizes). Strains from Australia, Chile, San Diego, and Atlantic and Mediterranean Europe were identifiable as A. armata Harvey, the gametophyte of which has distinctive barbed spines. This species is believed to be endemic to cold-temperate waters of Australia and New Zealand and was introduced into Europe in the 1920s. All isolates showed identical cpDNA RFLPs, consistent with a recent introduction from Australia. Asparagopsis taxiformis (Delile) Trevisan, the type and only other recognized species, which lacks spines, is cosmopolitan in warm-temperate to tropical waters. Two clades differed morphologically and ecophysiologically and in the future could be recognized as sibling species or subspecies. A Pacific/Italian clade had 4-8°C lower survival minima and included a genetically distinct apomictic isolate from Western Australia that corresponded to the form of A. taxiformis originally described as A. sanfordiana Harvey. The second clade, from the Caribbean and the Canaries, is stenothermal (subtropical to tropical) with some ecorypic variation. The genus Asparagopsis consists of two or possibly three species, but a definitive taxonomic treatment of the two A. taxiformis clades requires study of field-collected gametophytes.

Source: Scopus

The invasive genus <i>Asparagopsis</i> (Bonnemaisoniaceae, Rhodophyta):: Molecular systematics, morphology, and ecophysiology of <i>Falkenbergia</i> isolates

Authors: Chualáin, F.N., Maggs, C.A., Saunders, G.W. and Guiry, M.D.

Journal: JOURNAL OF PHYCOLOGY

Volume: 40

Issue: 6

Pages: 1112-1126

eISSN: 1529-8817

ISSN: 0022-3646

DOI: 10.1111/j.1529-8817.2004.03135.x

Source: Web of Science (Lite)