Hormophysa cuneiformis (PROSEA)
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Introduction |
Hormophysa cuneiformis (J.F. Gmelin) P.C. Silva
- Protologue: Smithsonian Contr. Mar. Sci. 27: 81 (1987).
- Family: Cystoseiraceae
- Chromosome number: 2n= unknown
Synonyms
- Fucus cuneiformis J.F. Gmelin (1792),
- Cystoseira triquetra C. Agardh (1820),
- Hormophysa articulata Kütz. (1860).
Vernacular names
- Indonesia: rumput laut (general name for seaweed)
- Malaysia: rumpair (general name for seaweed)
- Philippines: samô (Cebuano), aragan (Ilocano).
Origin and geographic distribution
H. cuneiformis is widely distributed in the Indian Ocean, the Red Sea and the Pacific Ocean, but has not been reported in Cambodia.
Uses
H. cuneiformis is used as animal feed, fertilizer, insect repellent, and foliar spray on crops in the Philippines. Its use in other South-East Asian countries is not well documented. It is a potential source of alginate and other natural products including phenols, carotene, chlorophyll a, chlorophyll c, fucoxanthin, tannins, laminarin and mannitol. Methanol and hexane extracts from this alga (as H. articulata) show antimicrobial activity especially against gram-positive bacteria, but they do not show antifungal activity.
Production and international trade
H. cuneiformis is usually harvested from natural populations together with other large brown algae such as Sargassum and Turbinaria spp. and is mentioned under brown algae, so no specific information on its production and trade is available.
Properties
For samples of H. cuneiformis (as H. triquetra) from Alabat, Quezon (the Philippines) an alginic acid yield of 41.8% (moisture-free basis) has been recorded. For material from Magnetic Island, Queensland (Australia) by following the Folin-Denis Assay, 2.3 ± 0.1% phenolic content (dry mass) was reported, while material from Qatar (Arabian Gulf) yielded 1.2% sterols, which was made up of 3.2% cholesterol, 86.7% fucosterol and 10.1% 24-methylene-cholesterol. Aqueous extracts of H. cuneiformis have high gibberellin-like activity when tested on rice.
Description
- Thalli erect, large, bushy, fleshy, up to 40 cm tall, attached to rocky substrate by discoidal holdfast from which several erect axes arise.
- Branches foliaceous, segmented; branching in multiple planes; segments three-ridged or triquetrous, with serrated to dentate margins, distal ones commonly with centrally disposed oblong vesicle embedded inside.
- Cryptostomata distinct, scattered on surfaces of segments.
- Life cycle diplontic.
- Plants monoecious. Conceptacles bisexual, scattered over thallus without distinctive receptacles.
- Oogonia sessile, ovoid or broad based, 80-120 μm × 35-60 μm, forming a single egg; antheridia sessile or on short, branched paraphyses, elongate-ovoid, 20-30 μm × 8-12 μm.
- Simple paraphyses also present in the conceptacles.
Growth and development
In the Philippines, H. cuneiformis has been collected at different months in different regions and appears to be present year-round. However, its phenology has not been examined in great detail.
Other botanical information
There is thallus variation in H. cuneiformis between estuarine and marine forms as a result of reduced cell enlargement and cell division in the estuarine form.
Ecology
H. cuneiformis is usually found growing with other large brown algae such as Sargassum spp. in shallow subtidal rocky shores exposed to moderate to strong waves. Its range of distribution, however, may be from estuarine to marine habitats. In western Australia, it has been found in an estuary with a salinity range of 45-50‰. Populations of this alga serve as a habitat for larvae of shrimps like Penaeus semisulcatus. However, it does not attract grazers like the sea urchins Diadema setosum and Heliocidaris erythrogramma.
Propagation and planting
H. cuneiformis is not known to be propagated artificially nor is it used in any phycoculture in South-East Asia. However, laboratory experiments to grow the alga on rope in India suggest that it would be easy to cultivate.
Harvesting
H. cuneiformis is not specifically targeted for harvest. Occasionally, it forms part of the harvest of other algae such as Sargassum spp.
Yield
Results of experimental rope culture in aquaria in India indicated that stipes increased at a rate of 89 mg wet weight per day, and fronds at a rate of 333 mg wet weight per day over a period of 150 days.
Handling after harvest
Samples of H. cuneiformis are usually harvested together with Sargassum spp., and air-dried. The viscosity of alginate extracted from H. cuneiformis increases from 77 cps (at room temperature) to 166 cps if the samples are pretreated overnight with 2% formaldehyde solution prior to extraction.
Prospects
H. cuneiformis is usually not a dominant component of the reef. Its further development as an economic alga is not expected in the immediate future unless unusual chemicals are found and can be isolated from it.
Literature
- Bhanderi, P.P. & Trivedi, Y.A., 1977. Rope culture of algin-yielding seaweed Hormophysa triquetra (Linnaeus) Kutzing. Botanica Marina 20: 183-185.
- Lasema, E.C., Veroy, R.L., Luistro, A.H., Montaño, N.E. & Cajipe, G.J.B., 1982. Alginic acid from some brown seaweeds. Kalikasan 11: 51-56.
- Papenfuss, G.F., 1967. The history, morphology and taxonomy of Hormophysa (Fucales: Cystoseiraceae). Phytomorphology 17: 42-47.
- Tupas, L.M. & Montaño, N.E., 1987. Effects of aqueous alkaline extracts from Philippine seaweeds as a foliar spray on crops. Philippine Journal of Science 17: 29-36.
Sources of illustration
Mairh, O.P. & Krishnamurthy, V., 1970. Some observations on the morphology and development of Hormophysa triquetra (C. Ag.) Kütz. Botanica Marina 13: figs. 1-11, p. 38 (holdfast, branches, sections of vegetative parts); Papenfuss, G.F., 1967. The history, morphology and taxonomy of Hormophysa (Fucales: Cystoseiraceae). Phytomorphology 17: fig. 4, p. 44 (detail of conceptacle); Trono, G.C. & Ganzon-Fortes, E.T., 1988. Philippine seaweeds. National Bookstore, Manila, The Philippines. Fig. 72B, p. 102 (apical portion of thallus); Womersley, H.B.S., 1987. The marine benthic flora of Southern Australia. Part 2. Handbook of the flora and fauna of South Australia. Adelaide, Australia. Fig. 131, p. 365 (sections of a fertile branch). Redrawn and adapted by P. Verheij-Hayes.
Authors
- P.O. Ang
