Komvophoron kgarii sp. nov. (Oscillatoriales), a new epipelic cyanobacterium from subtropical eastern Australia

Abstract

McGregor G.B. and Sendall B.C. 2013. Komvophoron kgarii sp. nov. (Oscillatoriales), a new epipelic cyanobacterium from subtropical eastern Australia. Phycologia 52: 472–480. DOI: 10.2216/13-143.1

A new epipelic freshwater cyanobacterium, Komvophoron kgarii sp. nov., was identified from a perennial wallum stream on Fraser Island, northeastern Australia. Komvophoron kgarii was the first species in Komvophoron that was described on the basis of combined morphological, ultrastructural and phylogenetic attributes. The new taxon was distinguished by virtue of its obtuse-conical apical cells that became conically elongated and narrowed toward the ends as they matured. Additionally, trichome separation into hormogonia was preceded by preapical cells beginning to differentiate on either side of the fragmentation point before separation, a feature not previously recorded in this genus. Ultrastructural examination showed that thylakoids formed irregularly arranged blocks of lamellae in both longitudinal and cross-sections. Phylogenetic analysis revealed that the isolated material shared less than 91% 16S ribosomal RNA nucleotide sequence similarity with any other cyanobacterial sequence and formed a novel branch.

Key Words::

• 16S rRNA
• Australia
• Borziaceae
• Cyanobacteria
• Komvophoron
• Oscillatoriales
• Subtropical

ACKNOWLEDGEMENTS

We thank Jamie Riches from the Analytical Electron Microscopy Facility, Queensland University of Technology for preparing samples and conducting the TEM analyses. We also thank Jon Marshall, Alisha Steward and Don Willis for assistance in collecting material for this study, Priya Muhid and John Bowlen for laboratory assistance in processing material for molecular analysis, and Julie Phillips, Wendy Williams and Jonathan Marshall for their critical comments on the manuscript.

SUPPLEMENTARY DATA

Supplementary data accociated with this article can be found online at http://dx.doi.org/10.2216/13-143.1.s1.