Grateloupia filicina (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

1, habit; 2, cross-section of thallus with carposporophyte; 3, cross-section of thallus with tetrasporangia.

Grateloupia filicina (J.V. Lamour.) C. Agardh

Protologue: Spec. alg. 1: 223 (1822).

Family: Halymeniaceae

Chromosome number: 2n= unknown

Synonyms

• Fucus filicina Wulfen (1791, nom. illeg.), Delesseria filicina J.V. Lamour. (1813).

Vernacular names

• Indonesia: sayur karang.

Origin and geographic distribution

G. filicina was first recorded in Trieste (Italy). It is considered to be cosmopolitan and is widely distributed in the Atlantic, Indian and Pacific Oceans. It occurs along the entire coast of China. In South-East Asia it has been recorded for Burma (Myanmar), East Malaysia, Indonesia (Java, Sumatra, Sumba) and the Philippines.

Uses

G. filicina is eaten as food in China and in some South-East Asian countries as a salad, in vegetable soup, as pickles and in home-made jellies. It is also a source of carrageenan and is used in medicine with anthelmintic and antibacterial properties or as a blood anticoagulant.

Production and international trade

No production data are available for G. filicina since biomass is obtained from natural stocks.

Properties

G. filicina contains floridosite and floridean starch (its principal reserve components), a polysaccharide known as galactan, and the steroids fucosterol and sitosterol (traces). It also contains 55.85 μM per gram dry weight of trimethylamineoxide which serves as the osmotic regulator or detoxicator of trimethylamine (TMA) substance in an organism. Reports of galactan-containing small proportions of D-L-galactose segments in what appeared to be D-D structures (carrageenan type), which might be considered hybrid molecules, have recently been confirmed in the¹³C Nuclear Magnetic Resonance (NMR) analysis of partial acetolysis products of galactan from related species in the genus.

Description

• Thalli purplish-red, gelatinous, with surface slippery, erect, linear, compressed to subcylindrical, caespitose, 15-20 cm tall, tapering to base and apex, shortly stipitate, anchored by small holdfast; branching generally pinnate, sometimes radial, branch pinnules 2-3 mm wide, commonly compressed subcylindrical.
• Internal structure filamentous, medulla composed of anastomosing filaments; cortex made up of anticlinal rows of cells.
• Life cycle triphasic, diplo-haplontic, isomorphic and dioecious.
• Tetrasporangia cruciate, scattered on the cortex of the frond.
• Antheridia in superficial patches on the cortex.
• Cystocarps, slightly prominent and embedded in the cortex.

Ecology

G. filicina grows attached firmly to dead corals and rocks on rocky, wave-exposed shores, edges of reefs or rocky walls of reef channels.

Propagation and planting

G. filicina is not grown in phycoculture.

Phycoculture

In the Philippines cultivation of G. filicina is still at the experimental stage and is not yet considered commercially feasible.

Harvesting

G. filicina is collected by hand from natural populations.

Handling after harvest

G. filicina is used fresh, blanched or air-dried.

Prospects

G. filicina shows good prospects for development in phycoculture.

Literature

• Nunn, J.R. & Parolis, H., 1970. Sulfated polysaccharides of Grateloupiaceae family IV. Methylation analysis of phyllymenan and desulfated phyllymenan. Carbohydrate Research 14: 145-150.
• Llana, E.G., 1990. Status of production and utilization of seaweeds in the Philippines. FAO/NACA report on the regional workshop on the culture and utilization of seaweeds, 27-31 August, 1990. Cebu City, The Philippines. pp. 124-249.
• Tenko, F.A. & Mino, N., 1972. The distribution of trimethylamine and trimethylamine oxide in marine algae. Proceedings of the seventh International Seaweed Symposium. University of Tokyo Press, Tokyo, Japan. pp. 506-510.
• Usov, A.I. & Borbakadze, V.V., 1978. Polysaccharide of algae. XXVII. Partial acetolysis of the sulfated galactan from the red seaweed Grateloupia sp. Okamura Bioorganiceska Chimija Akademija Nauk SSSR 4: 1107-1115.

Sources of illustration

Stegenga, H., Bolton, J.J. & Anderson, R.J., 1997. Seaweeds of the South African west coast. Contributions from the Bolus Herbarium 18: Plate 95, p. 290. Redrawn and adapted by P. Verheij-Hayes.

Authors

• G.C. Trono Jr