Melanamansia glomerata (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

1, rosette of linear-lanceolate blades; 2, cross-section of blade showing 2 layers of cells in V-shaped transverse rows; 3, surface view of cells of a blade; 4, arrangement of pericentral cells and pseudopericentral cells (arrows) in a diagrammatic cross-section through a non-corticated part of a midrib of a blade; 5, marginal curved stichidium bearing tetrasporangia. Amansia rhodantha (from South Africa, originally described as belonging to A. glomerata) - 6, habit, comparable to habit of Melanamansia glomerata.

Melanamansia glomerata (C. Agardh) R.E. Norris

Protologue: Taxon 44: 66 (1995).

Family: Rhodomelaceae

Chromosome number: 2n= unknown

Synonyms

• Amansia glomerata C. Agardh (1822).

Origin and geographic distribution

M. glomerata mainly occurs most probably in the Pacific Ocean: Japan, Taiwan, Hawaii, Australia (Queensland), New Caledonia, Samoa, Fiji. In South-East Asia it has been recorded in northern Burma (Myanmar), Indonesia, the Philippines and Papua New Guinea.

Uses

M. glomerata has no economic value yet in Indonesia. In the Philippines it is cited as having some economic potential as a medicine and antibiotic. It is a food source for green turtle.

Properties

M. glomerata contains medicinal compounds with antibiotic and antibacterial properties. This information on antibiotic potential has probably been derived from data on Amansia multifida J.V. Lamour. from Puerto Rico in the Caribbean.

Description

• Thalli pink to brownish-red, 4-6(-15) cm tall, forming thick clumps or mats, attached to the substrate by well-developed holdfasts bearing cylindrical to slightly compressed, irregularly branched, cartilagineous axes, 0.5-0.7 mm thick.
• Ultimate branches in mature plants with crowded rosettes of linear-lanceolate blades with irregular serrate margins; blades up to 35 mm long, up to 7 mm broad and up to 80 μm thick, composed of 2 layers of elongated cells in V-shaped transverse rows, without cortication except at midrib; marginal teeth up to 1.3 mm long and up to 450 μm broad; central midrib present in each blade, thickly corticated, becoming narrower and disappearing towards the apex.
• Each central axial cell surrounded by 5 pericentral cells, with the first 2 dorsal pericentral cells each developing a smaller pseudo-pericentral cell lying adjacent to the central axial cell.
• Only tetrasporophytes known.
• Curved tetrasporangial stichidia, up to 340 μm long and up to 250 μm broad, in median portions of the blades, terminate on small, endogenous, pinnate, determinate laterals or on the marginal teeth of the blades, with 3-7 together.
• Tetraspores tetrahedrally divided, roundish, 80 μm × 100 μm, up to 8 per stichidium, in two longitudinal rows.
• Life cycle not completely known, but probably diplo-haplontic and isomorphic.

Growth and development

There is a lack of information on the seasonality and reproduction of M. glomerata. It is not known for certain whether there are male and female plants of M. glomerata. The alga probably is perennial. In Indonesia, in the Spermonde Islands (South Sulawesi), Seribu Islands (Java Sea) and Bali, it grows abundantly in the dry season (August).

Other botanical information

M. glomerata is characterized by its rosettes. However, confusion occurs with a similar species, Amansia rhodantha (Harv.) J. Agardh. In the latter pseudo-pericentral cells do not develop in the midribs, whereas it occurs in the western Indian Ocean, especially subtidally or in deep tide pools, and has also been cited as occurring in the Philippines. All data on Amansia glomerata and A. rhodantha in the region need careful checking. Indonesian specimens that have been identified belong clearly to M. glomerata.

Ecology

M. glomerata occurs in the intertidal part of reef flats in areas moderately exposed to waves and currents. Usually the plants do not fully become exposed to air at low tide. It is also found on seaward platforms, mainly in shaded habitats. It grows on coral rubble in shallow water, forming dense carpet-like beds and is often partly covered by sand particles. It also occurs subtidally; the characteristic rosettes are less well developed there.

Propagation and planting

M. glomerata is not grown in phycoculture.

Harvesting

M. glomerata is collected from natural stands.

Prospects

M. glomerata may have good prospects because world demand for chemical compounds from marine algae is increasing steadily, both for industrial purposes and for food additives.

Literature

• Burkholder, P.R., Burkholder L.M. & Almodóvar, L.R, 1960. Antibiotic activity of some marine algae of Puerto Rico. Botanica Marina 2: 149-156.
• De Ramon N'Yeurt, A., 1996. A preliminary floristic survey of the benthic marine algae of Rotuma Island. Australian Systematic Botany 9: 361-490.
• Norris, R.E., 1988. Structure and reproduction of Amansia and Melanamansia gen. nov. (Rhodophyta, Rhodomelaceae) on the souteastern African coast. Journal of Phycology 24: 209-223.
• Norris, R.E., 1995. Melanamansia glomerata, comb. nov., and Amansia rhodantha, two hitherto confused species of Indo-Pacific Rhodophyceae. Taxon 44: 65-68.

Sources of illustration

Cribb, A.B., 1983. Marine algae of the southern Great Barrier Reef - Rhodophyta. Australian Coral Reef Society Handbook No 2. Brisbane, Australia. Plate 31, fig. 1 (rosette); Norris, R.E., 1988. Structure and reproduction of Amansia and Melanamansia Gen. Nov. (Rhodophyta, Rhodomelaceae) on the southeastern African coast. Journal of Phycology 24: Fig. 2, p. 212 (diagram section of blade, habit Amansia rhodanta); N'Yeurt, A.D.R., 1996. A preliminary floristic survey of the benthic marine algae of Rotuma Island. Australian Systematic Botany 9: Fig. 185, p. 483 (stichidium), fig. 197 & 198 (details of cells). Redrawn and adapted by P. Verheij-Hayes.

Authors

• W.S. Atmadja & W.F. Prud'homme van Reine