Electronic Flora of South Australia Species Fact Sheet

Predaea huismanii Kraft 1984a: 7, figs 15–24.

Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Nemastomataceae

Selected citations: Millar & Guiry 1989: 420. Verlaque 1990b: 499.

Thallus (Fig. 87A) erect, mucilaginous, compressed and cleft into lobes 1–2 cm long, 4–9 mm broad and 3–5 mm thick, with rounded margins. Holdfast discoid; epilithic. Structure of a cortex of fascicles (Fig. 87B) of simple (basally branched) filaments 20–35 cells and 700–1000 long, 4–6 µm in diameter with cells LID 3–6 (–8), protruding beyond shorter cortical systems 5–12 cells and 100–200 µm long, and a broad, laxly filamentous, medulla. Rhodoplasts several per cell, discoid.

Reproduction: Sexual thalli monoecious. Carpogonial branches (Fig. 86F) 3-celled, borne on inner cells of cortical system. Auxiliary cells (Fig. 87C) intercalary in nearby inner cortical systems, with 1–3-celled chains of nutritive cellules on the adjacent cells. Gonimoblast initial (Fig. 87C) developing on connecting filament adjacent to auxiliary cell, carposporophyte (Fig. 87B) obovoid, 70–75 µm long and 50–60 µm in diameter, consisting of 1–3 gonimolobes of subspherical carposporangia, each 8–10 µm in diameter. Spermatangia (Fig. 86G) on short, distichous branches at ends of short cortical systems, 2–3 µm in diameter.

Tetrasporophytes unknown.

Type from Rottnest I., W. Aust., 12 m deep (Huisman, 5.xii.1980); holotype in MELU, .K7163.

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

Distribution: Only known from the type locality and Pearson I., S. Aust., 12 m deep (Turner, 27.iii.1982; AD, A53054).

Taxonomic notes: The above Pearson I. specimen is fragmentary, 5.5 cm long, 4–6 mm broad, with one short lateral, but agrees with P. huismanii in structure and reproduction.


KRAFT, G.T. (1984a). The red algal genus Predaea (Nemastomataceae, Gigartinales) in Australia. Phycologia 23, 3–20.

MILLAR, A.J.K. & GUIRY, M.D. (1989). Morphology and life history of Predaea kraftiana sp. nov. (Gymnophloeaceae, Rhodophyta) from Australia. Phycologia 28, 409–421.

VERLAQUE, M. (1990b). Contribution a l'etude du genre Predaea (Rhodophyta) en Méditerranée. Phycologia 29, 489–500.

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

Author: by H.B.S. Womersley & G.T. Kraft

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 86F, G, 87 A–C.

Figure 86 image

Figure 86   enlarge

Fig. 86. A–E. Adelophycus corneus (A, MELU, K2102; B–D, AD, A34126; E, MELU, K4500). A. Branches with constrictions and cystocarps (on right). B. Transverse section with cortical gland cells and 3-celled carpogonial branches. C. Transverse section with auxiliary cell rhizoids. D. Lower carposporangia from an auxiliary cell. E. Transverse section of cortex with spermatangia. F, G. Predaea huismanii (AD, A53054). F. Cortical filaments with a carpogonial branch. G. Terminal group of spermatangia. [A–E after Kraft 1975.]

Figure 87 image

Figure 87   enlarge

Fig. 87. A–C. Predaea huismanii (AD, A53054). A. Habit of the southern Australian record. B. Fascicles of cortical filaments with two carposporophytes. C. Auxiliary cell with attached bulbous end of connecting filament producing a carposporophyte, with chains of small nutritive cellules on cells adjacent to auxiliary cell. D. Tsengia feredayae (AD, A19622). Habit. E. Tsengia comosa (AD, A29677). Habit. F. Tsengia laingii (AD, A35160). Habit.

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