Electronic Flora of South Australia Species Fact Sheet
Phylum Rhodophyta – Class Florideophyceae – Order Gelidiales – Family Gelidiaceae
Selected citations: Fuhrer et al. 1981: pl. 41. Gepp & Gepp 1906: 253. Harvey 1863: pl. 248. Millar 1990: 313, fig. 8E. Moore 1945: 338, figs 5–10, pls 47–49. Santelices 1991: 9, figs 19–22.
Fucus lucidus Turner 1819: 98, pl. 238.
Gelidium lucidum (Turner) Sonder 1848: 174. Kützing 1849: 763; 1868: 15, pl. 42 b-d.
Thallus (Fig. 40A) red-brown to dark red, 8–40 cm long, cartilaginous, with few to several erect, bi- to tripinnate, complanate fronds (Fig. 41A) from a fibrous to hapteroid, stoloniferous base. Axes flat, 3–4 mm broad centrally and above, with a thicker midrib below, with broad apices when actively growing but tapering in some plants, alternately distichously branched at intervals of (1–) 2–5 (–10) mm, pinnae with rounded axils, not or partly denuded below. Pinnae flat, 2–10 cm long and 1–3 (–4) mm broad, thicker centrally, slightly basally constricted, usually with broad apices. Pinnules alternate, flat, 2–5 mm long and 0.3–1 mm broad, basally slightly constricted. Holdfast discoid, becoming stoloniferous; epilithic. Structure (Fig. 41B). Cortex 3–5 cells thick, outer cells in surface view in rows spreading outwards, rounded with the protoplast 3–5 p.m across; medulla 7–12 cells thick with hyphae in older (midrib) parts; rhizines profuse, especially in outer medulla in older parts.
Reproduction: Cystocarps (Fig. 41C) single, lying near the end of pinnules, round to ovate, 600–1000 µm across, unilocular with 1–4 ostioles in the raised pericarp; carposporophyte (Fig. 40B) broad-based, with carposporangia in short chains, maturing apically, clavate to ovoid, 14–22 µm in diameter. Spermatangial sori on pinnules, spermatangial initials (Fig. 41D) cut off from outer cortical cells, elongate, 1.5–2.5 µm in diameter.
Tetrasporangial sori (Fig. 41A) in small pinnules or on ovate to elongate compressed ramuli on margins of pinnae or pinnules, 1–2 (–3) mm long and 300–800 1.1M broad; medulla slight; tetrasporangia (Fig. 41E) in regular arrangement near apex of sori, becoming mixed, derived from cortical cells and lying in the inner cortex, ovoid, 20–30 µm in diameter, cruciately divided (usually decussately).
Type from "S coast of N. Ho11." (Brown); holotype in BM.
Selected specimens: Murchison R. mouth, W. Aust., drift (Levring, 24.vi.1948; AD, A59045). Flat Rocks, 40 km S of Geraldton, W. Aust., drift (Mitchell, 17.ix.1966; AD, A31085). Whitford Beach, Perth, W. Aust., 4 m deep on onshore reef (Cook, 20.viii.1979; AD, A50559) and 6 m deep on offshore reef (Cook, 20.viii.1979; AD, A50574). Point Sinclair, S. Aust., upper sublittoral (Womersley, 9.ii.1954; AD, A19550). Wedge I., S. Aust., 22–38 m deep, 7 km SE (Baldock, 4.i.1964; AD, A27189). Aldinga, S. Aust., 4–6 m deep (URGSA, 23.xi.1958; AD, A22024). West I., S. Aust., 19 m deep (Shepherd, 17.viii.1968; AD, A32644 -"Marine Algae of southern Australia" No. 79). Stanley Beach, Kangaroo I., S. Aust., drift (Womersley, 6.ii.1957; AD, A20916). Nora Creina, S. Aust., 3–8 m deep (Owen, 3.ix.1971; AD, A39591). Lady Julia Percy I., Vic., 5–8 m deep (Shepherd, 3.i.1968; AD, A32401). Walkerville, Vic., drift (Sinkora A2281, 6.iii.1976; AD, A48454). West Point, Erith I., Bass Strait, 15 m deep (Shepherd & R. Lewis, 7.v.1974; AD, A45215). Gabo I., Vic., 24 m deep (Shepherd, 14.ii.1973; AD, A43317). Marrawah, Tas. (Perrin, Mar. 1950; AD, A49718). Green Cape, N.S.W., 16 m deep (Shepherd, 13.ii.1973; AD, A43034).
Distribution: New Zealand.
Murchison R. mouth (Kalbarri), W. Aust., around southern Australia and Tasmania to Coffs Harbour, N.S.W.
Taxonomic notes: P. lucida is a common subtidal species on rough-water coasts, but nowhere in southern Australia has it been observed, either in situ or drift, in quantities sufficient to permit harvesting as a source of agar, as in New Zealand.
A New Zealand robust form of P. lucida was segregated by Akatsuka (1986a) as a new genus and species, Pterocladiastrum robustum, with surface cell arrangement in tetrads (actually more in rows) and anticlinal in section, the subsurface cells being oblique to the surface. Such features scarcely warrant generic distinction and are found variably in specimens from southern Australia. They probably result from the state of growth of the surface layer and outer cortex, which thickens in older parts of the thallus. Similar variation is shown in P. capillacea. Nelson & Adams (1987, p. 29) also state that in New Zealand they "are unable to distinguish Pterocladiastrum from Pterocladia lucida".
AGARDH, J.G. (1852). Species Genera et Ordines Algarum. Vol. 2, Part 2, pp. 337–720. (Gleerup: Lund.)
AGARDH, J.G. (1876). Species Genera et Ordines Algarum. Vol. 3, Part 1 - Epicrisis systematis Floridearum, pp. i-vii, 1–724. (Weigel: Leipzig.)
AKATSUKA, I. (1986a). Pterocladiastrum, a new genus segregated from Pterocladia (Gélidiales, Rhodophyta). Bot. Mar. 29, 51–58.
FUHRER, B., CHRISTIANSON, I.G., CLAYTON, M.N. & ALLENDER, B.M. (1981). Seaweeds of Australia. (Reed: Sydney.)
GEPP, A. & GEPP, E.S. (1906). Some marine algae from New South Wales. J. Bot., Lond. 1906, 249–261, Plate 481.
HARVEY, W.H. (1863). Phycologia Australica. Vol. 5, Plates 241–300, synop., pp. i-lxxiii. (Reeve: London.)
KÜTZING, F.T. (1849). Species Algarum. (Leipzig.)
KÜTZING, F.T. (1868). Tabulae Phycologicae. Vol. 18. (Nordhausen.)
MILLAR, A.J.K. (1990). Marine Red Algae of the Coffs Harbour Region, northern New South Wales. Aust. Syst. Bot. 3, 293–593.
MOORE, L.B. (1945). The genus Pterocladia in New Zealand. Trans. R. Soc. N.Z. 74, 332–342, Plates 45–49.
NELSON, W.A. & ADAMS, N.M. (1987). Marine Algae of the Bay of Islands area. Nat. Mus. N.Z., Misc. Ser. No. 16, pp. 1–47.
SANTELICES, B. (1991). Variations in Cystocarp Structure in Pterocladia (Gélidiales: Rhodophyta). Pacific Sci. 45, 1–11.
SONDER, O.W. (1848). Algae. In Lehmann, C., Plantae Preissianae. Vol. 2, pp. 161–195. (Hamburg.)
TURNER, D. (1819). Fuci sive Plantarum Fucorum Generi a Botanicis Ascriptarum Icones Descriptiones et Historia. Vol. 4, pp. 1–153, Plates 197–258. (London.)
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.
Illustrations in Womersley Part IIIA, 1994: PLATE 2 fig. 4; FIGS 40A, B, 41 A–E.
Plate 2 enlarge
PLATE 2 fig. 1. Porphyra columbina at Cape Lannes, S. Aust. (AD, A62998). fig. 2. Liagora farinosa near Coffin I., Albany, W. Aust. (in Murdoch). Photo: J.M. Huisman. fig. 3. Capreolia implexa (mat) and Hormosira banksii at Cape Lannes, S. Aust. (AD, A62999). fig. 4. Pterocladia lucida at Erith I., Bass Strait. (AD, A45215). Photo: S.A. Shepherd.
Figure 40 enlarge
Fig. 40. A, B. Pterocladia lucida (A, B, AD, A32644). A. Habit. B. Section through cystocarp showing entangled filaments forming a broad base to the carposporophyte, carposporangia and one ostiole. C. Pterocladia capillacea (AD, A22897). Habit. D–F. Pterocladia rectangularis (D, AD, A34231; E, F, AD, A59041). D. Habit. E. Cystocarps with prominent ostioles. F. Carposporophyte with secondary cell row and carposporangia (upper pericarp wall displaced).
Figure 41 enlarge
Fig. 41. A–E. Pterocladia lucida (AD, A32644). A. Habit, with tetrasporangial sori. B. Transverse section of thallus. C. Cystocarp with four ostioles. D. Transverse section with elongate spermatangial initials. E. Transverse section of tetrasporangial sorus. F–J. Pterocladia capillacea (AD, A22897). F. Branch with elongate cystocarps, the central one with two ostioles. G. Cross section of cystocarp, with the carposporophyte tufted around the axial cell, elongate cells connecting to the pericarp, and single ostiole. H. Transverse section of thallus. I. Branch with tetrasporangial sori. J. Cross section of tetrasporangial sorus. K. Pterocladia rectangularis (AD, A14009). Branch with tetrasporangial stichidia.
State Herbarium of South Australia