• ALGAE
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• v.26 no.2
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• pp.167-180
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• 2011

The unicellular marine red alga Erythrolobus australicus sp. nov. (Porphyridiophyceae) was isolated into laboratory culture from mangroves in Queensland and New South Wales, Australia. The single multi-lobed red to rose-red plastid has more than one pyrenoid and lacks a peripheral thylakoid. Arrays of small electron dense globules occur along the thylakoids. The nucleus is peripheral with a central to eccentric nucleolus. Each Golgi body is associated with a mitochondrion. The spherical cells are positively phototactic with slow gliding movement. The psaA + psbA phylogeny clearly showed that E. australicus is a distinct species, which is closely related to E. coxiae. The chemotaxonomically relevant and most abundant low molecular weight carbohydrate in E. australicus is floridoside with concentrations between 209 and 231 ${\mu}mol g^{-1}$ dry weight. Traces of digeneaside were also detected. These various approaches help to understand the taxonomic diversity of unicellular red algae.

• ALGAE
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• v.21 no.4
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• pp.407-416
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• 2006

Low molecular weight carbohydrates, phycobilin pigments and cell structure using light and transmission electron microscopy were used to describe a new genus of unicellular red algae, Erythrolobus coxiae (Porphyridiales, Porphyrideophyceae, Rhodophyta). The nucleus of Erythrolobus is located at the cell periphery and the pyrenoid, enclosed by a cytoplasmic starch sheath, is in the cell center. The pyrenoid matrix contains branched tubular thylakoids and four or more chloroplast lobes extend from the pyrenoid along the cell periphery. A peripheral encircling thylakoid is absent. The Golgi apparatus faces outward at the cell periphery and is always associated with a mitochondrion. Porphyridium and Flintiella, the other members of the Porphyrideophyceae, also lack a peripheral encircling thylakoid and have an ER-mitochondria-Golgi association. The low molecular weight carbohydrates digeneaside and floridoside are present, unlike both Porphyridium and Flintiella, which have only floridoside. The phycobilin pigments B-phycoerythrin, R-phycocyanin and allophycocyanin are present, similar to Porphyridium purpureum. The cells have a slow gliding motility without changing shape and do not require substrate contact. The ultrastructural features are unique to members of the Porphyrideophyceae and recent molecular analyses clearly establish the validity of this new red algal class and the genus Erythrolobus.

• ALGAE
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• v.28 no.3
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• pp.241-266
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• 2013

The mangrove algal flora of Guam and the Federated States of Micronesia has been poorly explored. We add to our knowledge of this region by observations of collections from these regions. This paper presents new and additional records of: Rhodophyta-Acrochaetium globosum, Colaconema sp., Caulacanthus indicus, Bostrychia moritziana / B. radicans, B. radicosa, B. simpliciuscula, B. kelanensis and B. tenella, Murrayella periclados, and Caloglossa ogasawaraensis; Chlorophyta-Boodleopsis carolinensis; and Phaeophyceae-Dictyota adnata, Dictyotopsis propagulifera, and Canistrocarpus cervicornis. Most specimens were cultured to investigate their reproductive biology and many specimens were further identified using molecular data. Low molecular weight carbohydrates (dulcitol, sorbitol, and digeneaside) were identified in samples of B. radicosa and B. simpliciuscula. We also present data on manganese-rich deposits found on B. simpliciuscula and B. tenella in culture, possibly formed by epiphytic bacteria.