Electronic Flora of South Australia Species Fact Sheet

Carpopeltis spongeaplexus Womersley & Lewis, nom. nov.

Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Halymeniaceae

Synonyms

Thamnoclonium decipiens J. Agardh 1885: 20.

Codiophyllum decipiens (J. Agardh) Schmitz 1895: 145. Scott, Wetherbee & Kraft 1984: 293, figs 18–23.

Thallus (Fig. 48C) dark red-brown to grey-brown, 3–15 (–18) cm high, cartilaginous, with most of the thallus irregularly branched, with flattened to flanged axes 1.5–3.5 mm broad, completely covered by tightly adherent sponge to a diameter of 0.5–1 (–2) cm, with lower axes developing a secondary cortex with up to 9 growth rings; uppermost branch systems free of the sponge, 1–2 (–6) cm long, mostly subdichotomously branched, branches 0.7–1.5 (–2) mm broad and 80–150 µm thick (more when fertile), with rounded apices. Holdfast divided, fibrous, 5–15 mm across; epilithic. Structure (Fig. 50D) of upper branch systems of a pseudoparenchymatous cortex 25–40 µm and 4–6 cells thick (thicker in fertile parts), outer cells 2–3 µm in diameter and L/D 2–3, becoming larger inwardly, and a dense and compact filamentous medulla 30–40 µm across; stellate and refractive ganglionic cells absent. Rhodoplasts discoid, few per cell.

Reproduction: Reproductive structures confined to upper parts of terminal branches extending beyond the sponge investment.

Sexual thalli with ampullae and cystocarps in oval sori just below branch apices. Carpogonial branch ampullae (Fig. 49G) simple, with 1–2 secondary branches, borne on inner cortical cells. Auxiliary cell ampullae (Fig. 49H) arising in inner cortex, 30–40 µm across, with numerous erect secondary and some tertiary filaments of elongate cells, converging slightly above in the outer cortex. Carposporophytes (Fig. 50D) closely adjacent, swelling branches to 250–350 µm thick, subspherical, compact, 100–160 µm across, with the basal auxiliary cell remaining; carposporangia ovoid to angular, 6–10 µm across. Involucre slight to moderate, formed from compacted ampullary filaments and inner cortical cells; ostiole present. Spermatangia not observed.

Tetrasporangia (Figs 49 I, 50E) in oval nemathecia near branch apices, among paraphyses 2–3 cells long, cut off from ovoid cells at the base of the paraphyses, 20–30 µm long and 6–10 µm in diameter, cruciately divided.

Type from Geographe Bay, W. Aust., lectotype in Herb. Agardh, LD, 23065; isolectotype in

Selected specimens: Tarkoola Beach, Geraldton, W. Aust., drift (Kraft, 9.x.1990; MELU, A39803). Point Clune, Rottnest I., W. Aust., 12–13 m deep (Kraft & Millar, 6.xii.1984; MELU, A38192). Strickland Bay, Rottnest 1., W. Aust., 2 m deep, shaded (Engler & Clarke, 5.ix.1979; AD, A51083). D'Entrecasteaux Reef, E of Head of the Great Australian Bight, S. Aust., 15–20 m deep (Shepherd, 27.iii.1980; AD, A52165). Nuyts Reef, S. Aust., 28–30 m deep (Shepherd, 26.iii.1980; AD, A52317). Daly Head, Yorke Pen., S. Aust., drift (Woelkerling, 22.iv.1969; AD, A34162). Port Elliot, S. Aust., drift (Woelkerling, 8.v.1968; AD, A32288).

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

Distribution: Geraldton, W. Aust., to Port Elliot, S. Aust., on rough-water coasts, 2–30 m deep.

Taxonomic notes: MEL, 606034.

* Drawings of ampullae generally show half the ampulla filaments, and the cells are shown with dots inside the wall.

C. spongeaplexus is clearly allied to Carpopeltis and not to Codiophyllum, and is characterised by the thick sponge cover over most of the thallus. A new name is required since C. decipiens (Harvey) Schmitz has previously been applied to a separate species in Western Australia. G.T. Kraft (pers. comm.) reports that thalli generally occur where strongly shaded and are either pendulous or sprawling.

The name is based on the sponge investment which is invariably present.

References:

AGARDH, J.G. (1885). Till algemes systematik. VII. Florideae. Acta Univ. lund. 21, 1–120, Plate 1.

SCHMITZ, F. (1895). Marine Florideen von Deutsch-Ostafrica. Bot. Jb. 21, 137–177.

SCOTT, F.J., WETHERBEE, R. & KRAFT, G.T. (1984). The morphology and development of some prominently stalked southern Australian Halymeniaceae (Cryptonemiales, Rhodophyta). B. The sponge-associated genera Thamnoclonium Kützing and Codiophyllum Gray. J. Phycol. 20, 286–295.

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

Author: H.B.S. Womersley & J.A. Lewis

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.

Illustrations in Womersley Part IIIA, 1994: FIGS 48C, 49 G–I, 50D, E.

Figure 48   enlarge

Fig. 48. A. Carpopeltis phyllophora (AD, A38128). Habit. B. Carpopeltis elata (AD, A50795). Habit. C. Carpopeltis spongeaplexus (AD, A52165). Habit. D. Polyopes constrictus (AD, A61546). Habit. E. Polyopes tenuis (AD, A35901). Habit.

Figure 49   enlarge

Fig. 49. A–C. Carpopeltis phyllophora (A, B, AD, A52313; C, AD, A46169). A. Carpogonial branch ampulla*. B. Auxiliary cell ampulla. C. Section of cortex with tetrasporangia. D–F. Carpopeltis elata (D, E, AD, A50765; F, MELU, A39787). D. Carpogonial branch ampulla. E. Auxiliary cell ampulla. F. Section of cortex with tetrasporangia (by J.A. Lewis). G–I. Carpopeltis spongeaplexus (G, H, AD, A51083; I, AD, A34162). G. Carpogonial branch ampulla. H. Auxiliary cell ampulla with first gonimoblast cell. I. Section of cortex with tetrasporangia.
* Drawings of ampullae generally show half the ampulla filaments, and the cells are shown with dots inside the wall.

Figure 50   enlarge

Fig. 50. A, B. Carpopeltis phyllophora (A, MELU, A38262; B, AD, A46169). A. Transverse section of thallus with cystocarps (Photo: J.A. Lewis). B. Transverse section of thallus with tetrasporangia. C. Carpopeltis elata (AD, A50765). Transverse section of thallus with cystocarps. D, E. Carpopeltis spongeaplexus (D, AD, A51083; E, AD, A34162). D. Transverse section of thallus with cystocarps. E. Transverse section of thallus with tetrasporangia. F, G. Polyopes constrictus (F, AD, A7010; G, AD, A41752). F. Transverse section with auxiliary cell ampullae. G. Longitudinal section of nemathecial thallus with tetrasporangia.

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