Electronic Flora of South Australia Species Fact Sheet
Phylum Chlorophyta – Order Derbesiales – Family Derbesiaceae
Selected citations: Kjellman 1897: 1, figs 1–15. Kobara & Chihara 1980: 214, figs 1–13. Kornmann & Sahling 1977: 53, fig. 21. MacRaild 1974: 99, figs V.1–6. Scagel 1966: 113, pl. 1. Sears & Wilce 1970: 381, figs 1–15,17–28. Womersley 1956: 371.
Sporophytic thallus (Fig. 99A) epiphytic or epilithic, 1–3 (–4) cm high, arising from irregularly branched, colourless, rhizoidal attachment filaments, with a fairly densely, but not closely, irregularly branched erect tuft of filaments (Fig. 98C). Filaments (25–) 30–40 µm in diameter, cylindrical and fairly straight, slightly contracted at the base of laterals, with a double septum at the base of occasional laterals (Fig. 98D); wall 1–2 µm thick; chloroplasts (Fig. 98E) numerous, usually densely aggregated, lenticular but usually rounded when preserved or stained, 4–6 pm long, without pyrenoids but often with 2–5 small starch plates within the chloroplast.
Gametophytic thallus (Halicystis ovalis) dioecious, ovoid, (345–10 mm long, occurring on crustose coralline algae in low-light habitats; chloroplasts round to lenticular, without a pyrenoid.
Reproduction: Sporangia (Fig. 98F,G) ovoid, 80–110(4 40) µm long and 50–65 µm broad, occasionally tapering to their base, cut off by a wall plug soon after initiation.
Reproduction (Gametophytic thallus) (Kobara & Chihara 1980) by biflagellate anisogametes.
Type from Quivig, Faroe Is; in C.
Selected specimens: Scott Bay (6 km W. of Fowler Bay), S. Aust., reef pools (Womersley, 27.i.1951; ADU, A14987). Vivonne Bay, Kangaroo I., S. Aust., in shaded pool, S. side of Ellen Point (Wornersley, 14.i.1948, 21.viii.1963, 18.xi.1967; ADU, A9477, A27020, A32094 resp.). Nora Creina, S. Aust., in heavily shaded pool (Womersley, 16.v.1982; ADU, A53085 and 28.ii.1983; ADU, A54010). Quiet Corner, Adventure Bay, Bruny I., Tas., 10 m deep (Shepherd, 16.ii.1972; ADU, A41587).
Halicystis stage (all subject to checking of living material from these localities). Nora Creina, S. Aust., on crustose coralline in heavily shaded pool (MacRaild & Womersley, 17.i.1971; ADU, A37810). Point Lonsdale, Vic., low eulittoral pool (Ducker, 21.ii.1975; MELU, 21916). Sorrento, Vic. (Ducker, 17.iv.1975; MELU, 22069).
Distribution: Widely distributed in cold temperate waters, though not frequently collected.
In southern Australia, from Scott Bay, S. Aust. to Sorrento, Vic. and Bruny l., Tas., usually in shaded pools with moderate water movement. The occurrence of the gametophyte (Halicystis) stage in southern Australia still has to be established, since most collections available have pyrenoids and are therefore referable to H. parvula (= D. tenuissima). Collections which have been referred to H. ovalis are listed below.
Taxonomic notes: The southern Australian specimens agree well with descriptions of D. marina from the Northern Hemisphere, though the life history of Australian plants has not been reported. Plants of D. marina and of D. tenuissima can occur in the same rock pool, as at Scott Bay, Vivonne Bay and Nora Creina, and can be separated on dimensions, the chloroplast size and whether a pyrenoid is present or not.
KJELLMAN, F.R. (1897). Debesia marina fran Norges nordkust. K. Sven. Vetenskapsakad. Handl. 23, Afd. III (5), 1–21, figs 1–15.
KOBARA, T. & CHIHARA, M. (1980). Laboratory culture and taxonomy of two species of Halicystis (Class Chlorophyceae) in Japan. Jap. J Phycol. 28, 211–217.
KORNMANN, P. & SAHLING, P.-H. (1977). Meeresalgen von Helgoländ. Benthische Grun-Braun-und Rotalgen. Helgoländer wiss. Meeresunters. 29, 1–292.
MacRAILD, G.N. (1974). The taxonomy, life history and cytology of Bryopsis and related genera from southern Australia. (Ph.D. thesis, Univ. Melbourne.)
SCAGEL, R.F. (1966). Marine algae of British Columbia and Northern Washington, Part I: Chlorophyceae (Green Algae). Natl Mus. Can. Bull. 207, i-viii, 1–257.
SEARS, J.R. & WILCE, R.T. (1970). Reproduction and systematics of the marine alga Derbesia (Chlorophyceae) in New England. J. Phycol. 6, 381–392.
WOMERSLEY, H.B.S. (1956). A critical survey of the marine algae of southern Australia. I. Chlorophyta. Aust. J. mar. freshw. Res. 7, 343–383.
The Marine Benthic Flora of Southern Australia Part I complete list of references.
Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
©Board of the Botanic Gardens and State Herbarium, Government of South Australia
Illustrations in Womersley Part I, 1984: FIGS 98 C–G, 99A.
Figure 98 enlarge
Fig. 98. A,B. Bryopsis gemellipara (ADU, A53202). A. Apex of a young axis with bilateral, slightly displaced ramuli. B. Part of an older axis with bilateral, displaced, laterals and radially arranged ramuli. C–G. Derbesia marina (C–E, ADU, A54010; F,G. ADU, A9477). C. Habit. D. Branch with basal double septum. E. Branch with chloroplasts. F,G. Sporangia.
Figure 99 enlarge
Fig. 99. A.Derbesia marina (ADU, A53085). B. Derbesia tenuisssima(AD U, A20276). C–F. Pedobesia clavaeformisC. Living thallus with sporangia (ADU, A37816 collection). D,E. Prostrate disc, showing concentric growth sectors, and meristematic periphery. E. Surface detail of prostrate disc (culture material, from MacRaild & Womersley 1954, Figs 7.9).
State Herbarium of South Australia