A Reassessment and Reclassification of Species in the Genera Onikusa Akatsuka and Suhria J. Agardh ex Endlicher (Gelidiales, Rhodophyta) Based on Molecular and Morphological Data

• Published in: Botanica marina Vol. 45; no. 6; pp. 548 - 558
• Main Authors: Tronchin, E. M., Freshwater, D. W., Bolton, J. J., Anderson, R. J.
• Format: Journal Article
• Language: English
• Published: 01.11.2002
• Subjects: DNA; Gelidiales; Gelidium; Gelidium foliaceum; Gelidium vittatum laceratum; Marine; Onikusa; rbcL gene; Suhria
• ISSN: 0006-8055
• DOI: 10.1515/BOT.2002.058

The phylogenetic relationships and taxonomic status of the Gelidialean genera Onikusa Akatsuka and Suhria J. Agardh ex Endlicher were examined based on analyses of molecular and morphological characters. The DNA sequences of rbcL from multiple specimens of all Onikusa and Suhria species were included in analyses of 38 Gelidialean taxa having the Gelidium-type female reproductive and cystocarp systems. Six well-supported species clades were resolved in these analyses. Two species of Onikusa and Suhria vittata (Linnaeus) Endlicher were resolved within the 'Suhria clade', and Onikusa japonica (Harvey) Akatsuka was resolved within the 'Gelidium chilense clade.' Gelidium Lamouroux was paraphyletic with respect to Onikusa and Suhria. Evidence for a turf-form ecotype of Onikusa pristoides was found. Examination of species resolved within the 'Suhria,' 'Gelidium chilense' and 'G. coulteri clades' revealed that the medullary structure type was not a synapomorphy for these clades. Based on these new and previous findings, the reversion of Suhria vittata, Onikusa pristoides (Turner) Akatsuka, and Onikusa japonica to Gelidium, and the new combinations Gelidium vittatum (Linnaeus) Kuetzing forma laceratum (Grunow) D.W. Freshwater and Gelidium foliaceum (Okamura) E.M. Tronchin are proposed.