Electronic Flora of South Australia Species Fact Sheet

Audouinella saviana (Meneghini) Woelkerling 1973b: 560, figs 56–60.

Phylum Rhodophyta – Class Florideophyceae – Order Acrochaetiales – Family Acrochaetiaceae

Selected citations: Garbary 1987: 163. Schneider 1983: 15.

Synonyms

Callithamnion savianum Meneghini 1840: 511.

Chantransia efflorescens var. thuretii Bornet 1904: XVI, pl. 1.

Chantransia thuretii (Bornet) Kylin 1907: 119, fig. 28. Rosenvinge 1909: 100, figs 30–33.

Acrochaetium thuretii (Bornet) Collins & Hervey 1917: 98. Levring 1953: 476.

Audouinella thuretii (Bornet) Woelkerling 1971: 36, figs 12,24; 1973a: 88. Garbary 1979b: 479,483; 1987: 184. Garbary et al. 1983: 58, fig. 24.

Thallus (Fig. 7E) medium to dark red, fading to grey-red, largely to entirely epiphytic, caespitose, usually 2–5 mm high; original spore sometimes recognizable in young thalli, eventually becoming obscured. Prostrate system (Fig. 7E) consisting of short filaments forming a small pseudoparenchymatous disc. Erect filaments (Fig. 7E, F) richly and irregularly branched with an occasional tendency towards alternate and secund arrangements. Cells (Fig. 7F, G) cylindrical, 7–9 (–13) µm in diameter and (20–) 30–50 µm long (L/D 3–6) in lower portions of main axes, 6–9 µm in diameter and (15–) 25–60 µm long (L/D 3–8) in laterals, sometimes tapering to 3–6 µm in diameter near the apices, each cell containing a single parietal, laminate to lobate, rhodoplast (Fig. 7G) with one pyrenoid. Hairs unknown.

Reproduction: Monosporangia (Fig. 7F, G) ovoid, 10–14 µm in diameter and 18–22 (–24) µm long, sessile or stalked, usually single, in secund series along the laterals or occasionally more scattered, sometimes replaced by sessile, cruciately divided tetrasporangia (Fig. 7H) 17–24 µm in diameter and 23–35 µm long.

Other reproductive structures unknown in southern Australian collections (see Dixon & Irvine 1977b, p. 120 for sexual reproduction).

Type from Cherbourg, France; holotype in PC.

Selected specimens: Point Walter, Swan R. estuary, W. Aust. (Allender, 11.xi.1967; AD, A32251). Claremont jetty, Swan R. estuary, W. Aust., 0–0.5 m deep on Gracilaria (Allender, 28.i.1969; AD, A33398 -"Marine Algae of southern Australia" No. 65). Crawley Bay, Swan R. estuary, W. Aust. (Allender, 19.v.1968; AD, A32291). South Perth (Royce 223, 20.viii.1949; PERTH). Margaret Brock Reef, off Cape Jaffa, S. Aust., on Liagora codii on Codium duthieae, 3 m deep (AIMS-NCI, Q66C 2479–6, 18.ii.1989; AD, A59610).

Distribution map based
on current data relating to
specimens held in the
State Herbarium of SA

Distribution: Nearly cosmopolitan, on a variety of algae and seagrasses.

In southern Australia, from the Swan R. estuary, W. Aust., to Margaret Brock Reef, Cape Jaffa, S. Aust., but probably much more widespread in calm localities.

Taxonomic notes: Woelkerling (1973b, p. 562) examined the type collections of A. saviana and A. thuretii and considered them conspecific, and this has been re-checked recently. While this is queried by some authors (e.g. Dixon & Irvine 1977b, p. 122; Garbary 1979b, p. 483), it is strongly supported by Schneider (1983, p. 16).

Sexual plants of Audouinella saviana have not been recorded from southern Australia but are described in detail by Kylin (1907) under Chantransia thuretii. Audouinella saviana differs from A. secundata in being much branched above and in having mostly stalked monosporangia often in series. Plants of Audouinella daviesii occasionally resemble those of A. saviana, but they differ in having somewhat smaller monosporangia which frequently occur on branched stalks. The record of Levring (1953, p. 476) of Acrochaetium thuretii is more likely to be of A. daviesii since some monosporangia are on branched stalks (AD, A19843, poor material). Stegenga & Borsje (1976, p. 26) suggest that A. dasyae Collins may be the sexual stage of A. saviana.

References:

BORNET, E. (1904). Deux Chantransia corymbifera Thuret. Acrochaetium et Chantransia. Bull. Soc. bot. Fr. 51 (suppl.), xiv-xxiii.

COLLINS, F.S. & HERVEY, A.B. (1917). The algae of Bermuda. Proc. Am. Acad. Arts Sci. 53(1), 3–195.

DIXON, P.S. & IRVINE, L.M. (1977b). Seaweeds of the British Isles. Vol. 1, Rhodophyta. Part I, Introduction, Nemaliales, Gigartinales. [British Museum (N.H.): London.]

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. (1907). Studien über die Algenflora der schwedischen Westkiiste. Dissertation. (Upsala.)

LEVRING, T. (1953). The marine algae of Australia. I. Rhodophyta: Goniotrichales, Bangiales and Némalionales. Arkiv för Bot. Ser. 2, 2, 457–530.

MENEGHINI, G. (1840). Botanische Notizen. Flora (Regensburg) 23, 510–512.

ROSENVINGE, L.K. (1909). The marine algae of Denmark. Part 1. Introduction. Rhodophyceae. 1. (Bangiales and Némalionales). K. danske Vidensk. Selsk. Biol. Skr., 7 Raekke, Afd. 7, 1–151, Plates 1, 2,2 maps.

SCHNEIDER, C.W. (1983). The red algal genus Audouinella Bory (Nemaliales: Acrochaetiaceae) from North Carolina. Smithsonian Contr. Mar. Sci. No. 22, pp. 1–25.

STEGENGA, H. & BORSJE, W.J. (1976). The morphology and life history of Acrochaetium dasyae Collins (Rhodophyta, Nemaliales). Acta Bot. Neerl. 25, 15–29.

WOELKERLING, W.J. (1971). Morphology and taxonomy of the Audouinella complex (Rhodophyta) in southern Australia. Aust. J. Bot. Suppl. 1, 1–91.

WOELKERLING, W.J. (1973a). The Audouinella complex (Rhodophyta) in the western Sargasso Sea. Rhodora 75, 78–101.

WOELKERLING, W.J. (1973b). The morphology and systematics of the Audouinella complex (Acrochaetiaceae, Rhodophyta) in northeastern United States. Rhodora 75, 529–621.

The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.

Author: W.J. Woelkerling & H.B.S. Womersley

Publication: 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. 7 E–H.

Figure 7   enlarge

Fig. 7. A–D. Audouinella floridula* (A, B, D, AD, A24423; C, AD, A19057). A. Branching pattern. B. Prostrate system and erect filaments, with young sporangia (numerous cells omitted at broken lines). C. Upper filament with young and mature tetrasporangia. D. Mature cells with rhodoplasts with pyrenoids. E–H. Audouinella saviana (E–G, AD, A33398; H, AD, A32291). E. Branching pattern, with prostrate system and monosporangia on upper branches. F. Upper branches with monosporangia. G. Cells with rhodoplasts and a monosporangium. H. Tetrasporangia.

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