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Electronic Flora of South Australia Species Fact Sheet

Choreonema thuretii (Bornet in Thuret & Bornet)Schmitz 1889: 455.

Phylum Rhodophyta – Class Florideophyceae – Order Corallinales – Family Corallinaceae – Subfamily Choreonematoideae

Selected citations: Adams 1994: 160. Afonso-Carrillo et al. 1986: 207, figs 1–5. Cabioch 1980: 707, figs A-D. Chamberlain & Irvine 1994a: 34, figs 10, 11. Minder 1910: 1, figs 1–9. Suneson 1937: 53, figs 33–35, pl. 3 figs 10–12. Woelkerling 1987a: 111, figs 1–25.


Melobesia thuretii Bornet in Thuret & Bornet 1878: 96, pl. 50 figs 1–8.

Endosiphonia thuretii (Bornet in Thuret & Bornet)Ardissone 1883: 451.

Melobesia deformans Solms-Laubach 1881: 57, pl. 1 fig. 5, pl. 3 figs 12, 26.

Lithothamnion deformans (Solms-Laubach) Foslie 1898a: 4.

Chaetolithon deformans (Solms-Laubach) Foslie 1898b:7. Woelkerling 1987b: 277, figs 1–7.

Thallus largely unconsolidated, mostly 0.3–2 mm in greatest extent, vegetative portions endophytic but conceptacles produced external to the host. Structure filamentous to partly pseudoparenchymatous; construction diffuse, consisting of several-celled simple or branched filaments with cells mostly 5–20 µm in diameter and 20–65 µm long; cell elongation characteristics uncertain; cell-fusions and secondary pit-connections absent; epithallial cells, haustoria, and trichocytes unknown.

Reproduction: Vegetative reproduction unknown. Gametangia and tetrasporangia formed in uniporate conceptacles produced external to the host. Bisporangia unknown.

Gametangial thalli dioecious. Carpogonia terminating 2-celled filaments arising from the female conceptacle chamber floor. Mature female-carposporangial conceptacle roofs protruding above the host surface, 15–20 µm thick, composed of one layer of cells above the chamber, conceptacle chambers 75–80 µm in diameter and 50–60 µm high. Mature carposporophytes composed of a conspicuous central fusion cell and several-celled gonimoblast filaments bearing terminal carposporangia 15–30 µm in diameter. Spermatangial filaments unbranched, arising from the floor, walls and roof of male conceptacle chambers, mature male conceptacle roofs protruding above the host surface, 15–20 µm thick, composed of one layer of cells above the chamber, conceptacle chambers 55–70 µm in diameter and 50–60 µm high.

Tetrasporangial conceptacle roofs protruding above the host surface, 15–20 µm thick above the chamber and composed of one layer of cells, conceptacle chambers 60–80 µm in diameter and 50–55 µm high; tetrasporangia scattered across the conceptacle chamber floor; each mature sporangium 8–20 µm in diameter and 35–50 µm long, containing zonately arranged tetraspores and possessing an apical plug that helps to block the single conceptacle pore prior to spore release.

Type from Pointe de Querqueville, France; lectotype in PC (unnumbered); designated by Woelkerling (1987a, p. 113); depicted in Woelkerling (1987a, p. 114, fig. 1).

Selected specimens: Kalbarri, W. Aust., 2–3 m deep on Jania (Woelkerling, 22.ii.1978; LTB, 11706). Jeannies Lookout, Rottnest I., W. Aust., 2–3 m deep on Haliptilon (Woelkerling, 11.ii.1978; LTB, 10920). Point Valliant, Two People Bay, W. Aust., 0–1 m deep on Jania (Woelkerling, 2.ii.1978; LTB, 10585). Rossiter Bay, Esperance, W. Aust., 1–2 m deep on Jania (Woelkerling, 28.i.1978; LTB, 10797). Point Malcolm, SW of Israelite Bay, W. Aust., 0–2 m deep on Jania (Woelkerling, Platt & Jones, 7.ii.1984; LTB, 14188). St Francis I., S. Aust., 0–2 m on Jania (Shepherd, 6.i.1971; AD, A38127 = LTB, 14771). Pearson I., S. Aust., 20–25 m deep on Jania (Shepherd, 8.i.1969; AD, A56898 = LTB, 14952). Pennington Bay, Kangaroo I., S. Aust., reef surface on Haliptilon (Womersley, 25.i.1944; AD, A56905 = LTB, 14777). Cape Willoughby, Kangaroo I., S. Aust., upper sublittoral on Jania and Haliptilon (Woelkerling, 25.ii.1979; LTB, 11566 and 11567 respectively). Port Fairy, Vic., lower eulittoral on Haliptilon (Woelkerling, 4.i.1979; LTB, 11716). Rye (Number 16 reef), Vic., upper sublittoral on Haliptilon (Woelkerling, 14.ii.1977; LTB, 11336). Walkerville, Vic., lower eulittoral on Haliptilon (Woelkerling, 28.xii.1978; LTB, 11737). Gabo I, Vic., 8 m deep on Haliptilon (Shepherd, 19.ii.1973; AD, A56904 = LTB, 14951). Hunter I., Tas., reef pools on Haliptilon (Bennett, 14.i.1954; AD, A56896 = LTB, 14946). Coles Bay, Tas., upper sublittoral on Jania (Womersley, 4.xi.1982; AD, A56885 = LTB, 14945). Triabunna, Tas., sublittoral on Jania (Cribb, 18.iii.1950; AD, A56889 = LTB, 14949). Cape Sorrell, Tas., lower eulittoral on Haliptilon (Bennett, 4.ii.I955; AD, A56981 = LTB, 14944).

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

Distribution: Widespread (Woelkerling 1987a, p. 115; 1988, p. 91).

In western and southern Australia, Kalbarri, W. Aust., to Gabo I., Vic., and around Tasmania.

Taxonomic notes: Choreonema thuretii has been found on the geniculate corallines Haliptilon roseum and less often on Jania verrucosa and J. micrarthrodia in southern Australia; host thalli containing the endophyte have been collected intertidally from pools and rock platforms and subtidally to depths of 25 m. In southern Australian collections, deformation of host axes in areas endophytised by C. thuretii is rare; this contrasts with reports of host distortion in European populations (Cabioch 1980; Chamberlain & Irvine 1994a, p. 36). The apical plugs on tetrasporangia stain well with toluidine blue but not with potassium permanganate (Woelkerling 1987a). Woelkerling (1987b) concluded that Chaetolithon deformans, known from a single southern Australian collection, is conspecific with Choreonema thuretii, and thus that Chaetolithon is a heterotypic synonym of Choreonema.


ADAMS, N.M. (1994). Seaweeds of New Zealand. (Cant. Univ. Press: Christchurch.)

AFONSO-CARRILLO, J., LOSADA-LIMA, A. & LEON-ARECIBIA, M.C. (1986). Sobre la posición sistemátic de Choreonema Schimitz (Corallinaceae, Rhodophyta). Vieraea 16, 207–210.

ARDISSONE, F. (1883). Phycologia mediterranea. Part 1. Floridée. Memorie Soc. Crittogam. Ital. 1, 1–516.

CABIOCH, J. (1980). Le parasitisme du Choreonema thuretii (Bornet) Schmitz (Rhodophycées, Corallinacées) et son interprétation. C. r. hebd. Séanc. Acad. Sci., Paris 290(D), 707–710.

CHAMBERLAIN, Y.M. & IRVINE, L.M. (1994a). Choreonematoideae Woelkerling. In Irvine, L. M. & Chamberlain, Y. M. (Eds), Seaweeds of the British Isles. Volume 1 Rhodophyta Part 2B Corallinales, Hildenbrandiales pp. 33–36. (HMSO: London.)

FOSLIE, M. (1898a). Systematical survey of the lithothamnia. K. norske Vidensk. Selsk. Skr. 1898(2), 1–7.

FOSLIE, M. (1898b). List of species of the lithothamnia. K. norske Vidensk. Selsk. Skr. 1898(3), 1–11.

MINDER, F. (1910). Die Fruchtentwicklung von Choreonema thureti. (Oberh. Ztg. Genossenschaft: Bad-Nauheim.)

SCHMITZ, F. (1889). Systematische Ubersicht der bisher bekannten Gattungen der Florideen. Flora, Jena 72, 435–456, Plate 21.

SOLMS-LAUBACH, H. (1881). Die Corallinenalgen des Golfes von Neapel and der angrenzenden Meeres-abschnitte. Fauna Flora Golf. Neapal 4, 1–64, Plates 1–3.

SUNESON, S. (1937). Studien über die entwicklungsgeschichte der Corallinaceen. Lunds Univ. Årsskr. N.F. Avd. 2, 33, 1–102, Plates 1–4.

THURET, G. & BORNET, E. (1878). Études Phycologiques. (G. Masson: Paris.)

WOELKERLING, W.J. (1987a). The genus Choreonema in southern Australia and its subfamilial classification within the Corallinaceae (Rhodophyta). Phycologia 26, 111–127.

WOELKERLING, W.J. (1987b). The disposition of Chaetolithon and its type species, C. deformans (Corallinaceae, Rhodophyta). Phycologia 26, 277–280.

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

Author: W.J. Woelkerling

Publication: Womersley, H.B.S. (28 June, 1996)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIB. Gracilarialse, Rhodymeniales, Corallinales and Bonnemaisoniales
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIB 1996, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.

Illustrations in Womersley Part IIIA, 1996: FIGS 92, 93.

Figure 92 image

Figure 92   enlarge

Fig. 92. Choreonema thuretii (A, LTB, 14777; B, LTB, 11566; C, LTB, 11737). A. Habit of Choreonema on Haliptilon roseum. B. Surface view of conceptacles of Choreonema on intergenicula of Haliptilon. C. Section of endophytic vegetative thallus with developing conceptacle protruding above host surface.

Figure 93 image

Figure 93   enlarge

Fig. 93. Choreonema thuretii (A, C, LTB, 11566; B, LTB, 11567; D, LTB, 10585). A. Section of mature tetrasporangial conceptacle. B. Section of female-carposporangial conceptacle with mature carpogonial filaments. C. Section of female-carposporangial conceptacle with mature carposporophyte. D. Section of male conceptacle with spermatangial filaments arising from chamber floor and walls.

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