Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Acrochaetiales – Family Acrochaetiaceae
Selected citations: Garbary et al. 1983: 37, fig. 15. Millar & Kraft 1993: 7.
Acrochaetium pacificum Kylin 1925: 11, fig. 4g-i. Dawson 1953: 29.
Rhodochorton pacificum (Kylin) Drew 1928: 169, pl. 38 fig. 25.
Colaconema pacificum (Kylin) Woelkerling 1971: 47, figs 17A–D, 26A.
Thallus (Fig. 11E) epiphytic, caespitose, 300–750 (–1000) µm high; sporelings unknown. Prostrate system (Fig. 11E) consisting of creeping, branched, more or less confluent filaments forming an irregular pseudoparenchymatous disc. Erect filaments (Fig. 11E, G) simple to moderately branched; laterals arising mostly from the upper portions of the main axes, irregularly to secundly arranged, and occasionally tapering towards the tips. Cells (Fig. 11G, I) cylindrical, 4–7 (–12) µm in diameter and 8–30 (–36) µm long, L/D 1.5–6, each containing a single parietal rhodoplast (Fig. 11I) with one pyrenoid. Terminal and pseudolateral hairs up to 200 µm long occur.
Reproduction: Monosporangia (Fig. 11F, G) ovoid, 6–9 µm in diameter and 8–12 (–15) µm long, sessile or stalked, single or in pairs, lateral or rarely terminal on main axes and laterals.
Tetrasporangia (Fig. 11H) rare, cruciately divided.
Other reproductive structures unknown.
Type locality not specified by Kylin (1925), who listed three localities near Friday Harbour, Washington, U.S.A.: Brown I., Shaw I. and Peavine Pass; lectotype in LD?
Selected specimens: Garden I., W. Aust., on Sargassum sp., upper sublittoral (Mitchell, 22.ix.1966; AD, A30884). Elliston, S. Aust., on Cladophoropsis herpestica, upper sublittoral (Woelkerling, 24.viii.1967; AD, A31994).
Distribution: San Juan County, Washington; Gulf of California.
In southern Australia, from Garden I., W. Aust., and Elliston, S. Aust. Twofold Bay, N.S.W.
Taxonomic notes: Relationships of A. pacifica with other species are discussed by Garbary et al. (1983, p. 37). The two southern Australian collections agree reasonably well with the descriptions of Kylin and others, but further collections from southern Australia are needed for verification of the occurrence of this species.
DAWSON, E.Y. (1953). Marine red algae of Pacific Mexico. Part I. Bangiales to Corallinaceae subf. Corallinoideae. Allan Hancock Pacif. Exped. 17, 1–239.
DREW, K.M. (1928). A revision of the genera Chantransia, Rhodochorton, and Acrochaetium with descriptions of the marine species of Rhodochorton (Naeg.) gen. emend. on the Pacific Coast of North America. Univ. Calif. Pubis Bot. 14, 139–224, Plates 37–48.
GARBARY, D.J. (1979b). Numerical Taxonomy and generic circumscription in the Acrochaetiaceae (Rhodophyta). Bot. Mar. 22, 477–492.
GARBARY, D.J. (1987). The Acrochaetiaceae (Rhodophyta): An annotated bibliography. Bibl. Phycol. 77, 1–267.
GARBARY, D.J., HANSEN, G.I. & SCAGEL, R.F. (1983). The marine algae of British Columbia and northern Washington: Division Rhodophyta (red algae), Class Florideophyceae, Orders Acrochaetiales and Nemaliales. Syesis 15 (suppl.), 1–102.
KYLIN, H. (1925). The marine red algae in the vicinity of the biological station at Friday Harbour, Washington. Lunds Univ. Årsskr. N.F. Avd. 2, 21, 1–87.
MILLAR, A.J.K. & KRAFT, G.T. (1993). Catalogue of Marine and Freshwater Red Algae (Rhodophyta) of New South Wales, including Lord Howe Island, South-western Pacific. Aust. Syst. Bot. 6, 1–90.
WOELKERLING, W.J. (1971). Morphology and taxonomy of the Audouinella complex (Rhodophyta) in southern Australia. Aust. J. Bot. Suppl. 1, 1–91.
The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.
Womersley, H.B.S. (14 January, 1994)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIA, Bangiophyceae and Florideophyceae (to Gigartinales)
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIA 1994, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.
Illustration in Womersley Part IIIA, 1994: FIG. 11 E–I.
Figure 11 enlarge
Fig. 11. A–D. Audouinella plumosa (AD, A31279). A. Branching pattern, with prostrate system and erect branches with monosporangia. B. Erect branches with distichous laterals and monosporangia, and hairs. C. Prostrate system with bases of erect branches. D. Cells each with a rhodoplast and pyrenoid, with young monosporangia. E–I. Audouinella pacifica (E, F, H, >I,G, AD, A30884). E. Young thallus with prostrate system and erect branches. F. Erect filament with monosporangia. G. Erect filament with monosporangia and a hair. H. Upper branch with a tetrasporangium. I. Cells each with a rhodoplast and pyrenoid. [B, C, F–H after Woelkerling 1971.]
State Herbarium of South Australia