Electronic Flora of South Australia Species Fact Sheet

Porphyropsis minuta Womersley & Conway 1975: 68, fig. 7.

Phylum Rhodophyta – Class Bangiophyceae – Order Compsopogonales – Family Erythrotrichiaceae

Selected citations: Millar & Kraft 1993: 5.

Thallus (Fig. 3A) greenish-brown to purple, with a pulvinate parenchymatous holdfast 50–100 (–200) µm across (cells without rhizoidal extensions) from which one to several minute, subspherical to ovoid, bladders (to 2 mm across) arise, later becoming sinuate and rupturing to form irregular monostromatic membranes (Fig. 3B) 2–5 (–12) mm high and across, often with convolute margins; epiphytic. Cells of bladders and membrane often in pairs or fours (Fig. 3C) following division, and lying in rows more or less at right angles, sometimes becoming irregular; membrane 8–12 µm thick, cells rounded to slightly elongate, 3–5 µm across, with a parietal rhodoplast filling most of the cell, without a pyrenoid.

Reproduction: Reproduction by monospores (Fig. 3B) released from whole cells near the margin of the membranes, subspherical to ovoid, 5–7 µm across.

Type from Pearson I., S. Aust., on Pterocladia capillacea, upper sublittoral (Specht, 17.ii.1960); holotype in AD, A24525.

Selected specimens: Garden I., W. Aust., on Pterocladia capillacea, upper sublittoral (Mitchell, 21.ix.1966; AD, A31192). Wittelbee Point, S. Aust., on P. capillacea, upper sublittoral (Womersley, 22.i.1951; AD, A15146). Aldinga, S. Aust., on Sargassum bracteolosum, upper sublittoral pools (Womersley, 11.ii.1968; AD, A32275). West I., S. Aust., 1.5–3 m deep, on Plocamium angustum (Shepherd, 5.ii.1967; AD, A32375). Vivonne Bay, Kangaroo I., S. Aust., on Gracilaria?, 2–6 m deep (Mitchell, 21.viii.1963; AD, A26963). Lawrence Rock, Vic., epiphytic, in rock pools (Beauglehole, 13.i.1954; AD, A20552). Collaroy, N.S.W., on P. capillacea (Tilden 307, 26.xii.1934; AD, A26325).


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

Distribution: Garden I., W. Aust., around southern Australia to Collaroy, N.S.W., epiphytic on Pterocladia capillacea and other firm-surfaced algae on rough-water coasts.

Taxonomic notes: Porphyropsis minuta is similar to P. coccinea in size and form, but differs in having the cells arranged in more distinct rows and in colour. Further study of the reproduction is needed from culture; near-marginal cells in AD, A20552 have divided to form small, subspherical packets of 4–16 cells, raising the possibility of sexual reproduction in this species. Kornmann & Sahling (1985, p. 231) suggest that formation of monospores from whole cells near the thallus margin should exclude P. minuta from Porphyropsis.

References:

KORNMANN, P. & SAHLING, P.-H. (1985). Erythropeltidaceen (Bangiophyceae, Rhodophyta) von Helgoland. Helgoländer Meeresunters. 39, 213–236.

MILLAR, A.J.K. & KRAFT, G.T. (1993). Catalogue of Marine and Freshwater Red Algae (Rhodophyta) of New South Wales, including Lord Howe Island, South-western Pacific. Aust. Syst. Bot. 6, 1–90.

WOMERSLEY, H.B.S. & CONWAY, E. (1975). Porphyra and Porphyropsis (Rhodophyta) in southern Australia. Trans. R. Soc. S. Aust. 99, 59–70.

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

Author: H.B.S. Womersley

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.


Illustration in Womersley Part IIIA, 1994: FIG. 3 A–C.

Figure 3 image

Figure 3   enlarge

Fig. 3. A–C. Porphyropsis minuta (AD, A24525). A. Mature thallus on Pterocladia. B. Cell arrangement. C. Older membrane, with some cells releasing monosporangia. D–H. Bangia atropurpurea subsp. atropurpurea (AD, A29541). D. Filaments. E. Female filaments in surface view, with carpogonia, one with a prototrichogyne and attached spermatia. F. Ditto, in mid sectional view. G. Male filament with packets of spermatangia.


Disclaimer Copyright Disclaimer Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Department of Environment, Water and Natural Resources