Halymenia (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Halymenia dilatata - 1, habit; 2, cross-section of a frond; 3, cross-section of a portion of a spermatangial sorus. H. maculata - 4, cross-section of a frond; 5, cross-section of a portion of a tetrasporophyte with tetrasporangia. H. durvillei - 6, habit.

Halymenia C. Agardh

Protologue: Syn. alg. Scand. XIX: 19, 35 (1817).

Family: Halymeniaceae

Chromosome number: x= unknown

Major species and synonyms

• Halymenia dilatata Zanardini, Flora 34: 35 (1851).

• Halymenia durvillei Bory, Voy. monde, Crypt. 4: 180, pl. 15 (as H. durvillaei) (1828).

• Halymenia formosa Harv. ex Kutz., Tab. phycol. 16: 33, pl. 91: figs g, h (1866), synonym: H. durvillei Bory var. formosa (Harv. ex Kütz.) Weber Bosse (1921).

• Halymenia maculata J. Agardh, Algern. syst. 7: 12 (1885).

Vernacular names

• Indonesia: rumput laut, lambu argo
• Philippines: gayong-gayong, lablabig, gargarnatis.

Origin and geographic distribution

Halymenia is widespread in tropical and subtropical waters. In South-East Asia H. dilatata, H. durvillei and H. maculata have been reported for Indonesia, the Philippines and Thailand. H. dilatata also occurs in Papua New Guinea (southern coast) and H. durvillei also in Peninsular Malaysia, Singapore and Papua New Guinea (northern coast). H. formosa has been reported for Malaysia, Singapore, the Philippines and eastern Indonesia.

Uses

H. durvillei is a known source of carrageenan. It is also used as food, especially as fresh salad. The dried form is first resoaked in water and then prepared as salad. A natural glue can be prepared from H. durvillei.

Production and international trade

No production data are available for natural populations of Halymenia.

Properties

The following contents of air-dried material have been determined for H. durvillei: crude fat (0.7% in material that was red and fresh when air-dried, 0.5% in material that was already bleached before being air-dried), crude protein (12.8% red, 11.9% bleached), iodine (6.2% red, 5.4% bleached), nitrogen (2.1% red, 1.9% bleached) and mannitol (35.5% red, 29.6% bleached). The carrageenan of H. durvillei is lambda carrageenan, which is the phycocolloid normally extracted from the temperate red alga Chondrus crispus Stackh. This phycocolloid is non-gelling and does not precipitate in KC1.

Description

• Plants of moderate to considerable size, foliaceous or bushy, generally of gelatinous or softly fleshy consistency; entire or variously lobed or branched.
• Structurally with medulla of slender filaments well separated in a soft jelly, often radiating from conspicuous ganglia-like cells; cortex of large inner cells, small outer cells, not in evident filamentous arrangement.
• Life cycle triphasic, diplo-haplontic, isomorphic or slightly heteromorphic.
• Tetrasporangia cruciately divided, scattered and immersed in the cortex.
• Gametophytes dioecious.
• Cystocarps immersed with pericarp of slender filaments.
• Carpospores discharging through a definite pore. Spermatangia in superficial sori.

H. dilatata.

• Thalli purplish-red with shades of green, gelatinous-membranous, 10-15 cm tall, 350-400 μm thick, attached by small scutate disc; sessile or shortly stipitate, with large transversely expanded blade, broadly oblong or irregularly lobed, 10-20(-40) cm wide, undulate-curled, simple or lobed; base reniform, subpeltate or cuneate; margin entire, crenulate, subdentate-sinuose or fimbricate with ligulate lobules.
• Cortex thin, with 3-5 cell layers; outermost cells shaped like rabbit ears; medullary filaments running in various directions, with highly refractive stellate cells.
• Tetrasporangia embedded in cortex, obovate or oblong in transverse section, 25-35 μm × 15 μm.
• Spermatangial sori covering the margins of the thallus.
• Cystocarps dot-like, deeply submerged, 200-250 μm in diameter, with ostiole.

H. durvillei.

• Thalli large, bushy, very slippery, up to 35 cm tall, red-orange or purple, soft cartilaginous and slimy when fresh, attached to rocky substrates by discoid holdfast. Fronds flattened, with or without short stipe supporting 2-4 main axes 5-15 mm broad, about 250 μm thick, all branching pinnately-alternately 4-5 times, not in a single plane; ultimate branchlets slender, linear with acuminate tips, sometimes furcipate; margins of fronds serrate; surfaces of axis beset with few spine-like projections.
• Medulla containing more than half of the frond, with ganglion-like cells connecting the other medullar cells by colourless slender filaments.
• Outer cortex two cell layers, shaped like rabbit ears; subcortex 4-6 layers of cells.
• Tetrasporangia 8 μm × 20 μm.
• Cystocarps 250-270 μm in diameter, with inconspicuous ostiole.

H. formosa.

• Almost identical to H. durvillei but fronds finely branched, very bushy, 10-20 cm tall.

H. maculata.

• Thalli thin, membranous, purplish to greenish, 8-12 cm tall, arising in an open cluster from scutate, shortly stalked holdfast; segments irregularly proliferous; branching subdichotomous especially at distal portion of the blade; blade margin entire.
• Tetrasporangial thallus with 2 layers of papilla-like or irregularly shaped outer cortical cells.
• Medullary cells periclinally arranged fusiform filaments, 3-10 μm in diameter, without conspicuous ganglionic centres and with occasional anticlinal medullary filaments, about 10 μm in diameter, reaching from one cortex to the opposite cortex.
• Tetrasporangia sunk between elongated outer cortical cells acting as paraphyses, 10-20 μm × 28-31 μm, ovoid, oblong or obovate in transverse section.
• In cystocarpic plants only a single layer of slightly elongated cortex cells present.
• Spermatangia superficially borne on outer cortical cells, covering most of the surfaces.
• Cystocarps 96 μm × 120 μm, with several gonimolobes, surrounded by moderate number of sterile filaments.

Ecology

Halymenia is commonly found attached to rocks in the lower intertidal to upper subtidal areas moderately exposed to wave action.

Propagation and planting

Halymenia is not yet grown in phycoculture.

Phycoculture

Research is still being done to develop a culture method suitable for commercial cultivation of Halymenia.

Harvesting

Halymenia is hand-collected from natural populations.

Handling after harvest

To use H. durvillei for the production of glue, the dried algae are cooked for two hours with water, boric acid and hydrogen peroxide. After straining through cheese cloth the extracted liquid is cooked for half an hour or until the glue acquires the proper adhesive property. Substances such as zinc oxide and Pyrola oil are often added.

Prospects

In Japan interest in dried Halymenia is increasing. The present limited supply for the seaweed salad market comes mainly from natural stocks. Demand for lambda-type carrageenan from H. durvillei from the seaweed industry is potentially large. This carrageenan is used as a blending agent for specially formulated products. The development of farming technology for H. durvillei is one of the challenges for seaweed farmers in the near future.

Literature

• Abbott, I.A., 1999. Notes on some species of Halymenia in the southwestern Pacific. In: Abbott, I.A. (Editor): Taxonomy of economic algae 7. pp. 163-172.
• Calmorin, L.P., 1993. Glue from the red seaweed, Halymenia. SICEN (Seaweed Information Center) Newsletter 4(2): 7.
• de Leon, C.A. & Domantay, J.S., 1971. Studies on some Philippine Rhodophytes and their colloidal contents. Acta Manilana, serie A, 8: 3-38.
• de Leon, A.I., Eufemio, N. & Pineda, M., 1963. Chemical composition of some Philippine algae. Philippine Journal of Science 92(1): 77-87.
• Kawaguchi, S. & Lewmanomont, K., 1999. Morphology and culture study of a red alga, Halymenia dilatata Zanardini, from Vietnam and Japan. In: Abbott, I.A. (Editor): Taxonomy of economic algae 7. pp. 147-161.
• 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. FAO, Cebu City, The Philippines. pp. 124-149.
• Xia, B. & Wang, Y., 1999. Taxonomic studies on Halymenia (Halymeniaceae, Halymeniales, Rhodophyta) from China. In: Abbott, I.A. (Editor): Taxonomy of economic algae 7. pp. 173-176.

Sources of illustration

Trono, G.C., 1998. Seaweeds. In: Carpenter, K.E. & Niem, V.H. (Editors): The living marine resources of the Western Central Pacific. Vol. 1. Seaweeds, corals, bivalves and gastropods. Food and Agriculture Organization of the United Nations, Rome, Italy. p. 80 (habit H. dilatata), p. 81 (habit H. durvillei); Xia, B. & Wang, Y., 1999. Taxonomic studies on Halymenia (Halymeniaceae, Halymeniales, Rhodophyta) from China. In: In: Abbott, I.A. (Editor): Taxonomy of economic seaweeds with reference to some Pacific and Caribbean species. Vol. 7. California Sea Grant College Program, La Jolla, United States. Figs. 2 & 3, p. 174 (H. dilatata, cross-section of a frond, cross-section spermatangial sorus), figs. 5 & 6, p. 175 (H. maculata, cross-section frond, cross-section tetrasporophyte). Redrawn and adapted by P. Verheij-Hayes.

Authors

• G.C. Trono Jr