Colpomenia sinuosa (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

1, habit; 2, transverse section through thallus; 3, detail of 2, with sorus of plurilocular zoidangia and hairs; 4, diagrammatic section of a sorus with both an unilocular and a plurilocular zoidangium; 5, zoid with an eyespot.

Colpomenia sinuosa (Mert. ex Roth) Derbès & Solier

Protologue: In: Castagne, Suppl. Cat. pl. Marseille: 95 (1851).

Family: Scytosiphonaceae

Chromosome number: 2n= unknown

Synonyms

• Ulva sinuosa Mert. ex Roth (1806),
• Asperococcus sinuosus (Mert. ex Roth) Bory (1832),
• Hydroclathrus sinuosum (Mert. ex Roth) Zanardini (1843).

Vernacular names

• Philippines: tabtaba (Ilocano).

Origin and geographic distribution

C. sinuosa is cosmopolitan in temperate, subtropical and tropical areas. In South-East Asia it is common in all countries.

Uses

C. sinuosa is used as human food, as a raw salad vegetable or blanched and then prepared into a salad. It is also used as animal feed and a good source of phenols, vitamins, folic and folinic acids, and amino acids such as alanine, aspartic acid, glutamic acid, glutamine, glycine, serine, threonine, tyrosine and valine. It is also used as a fertilizer and as an indicator of metal pollution.

Properties

The sterol composition of C. sinuosa is unusual for brown algae, because of its rather low level of fucosterol but high levels of 24-methylene cholesterol and cholesterol. It contains fairly low levels of alginic acid and antioxidant properties have been recorded.

Description

• Macrothalli yellow-brown, globular, hemispherical, hollow, smooth to irregularly convoluted, expanding with age to 5-10 cm or more in diameter; cross-section of the membrane showing cortex of 1-2 layers of small cuboidal or polygonal cells with chromatophores, about 5-8 μm in diameter; medulla with 4-6 layers of colourless cells, irregularly shaped, more or less rounded or polygonal.
• Plurilocular sporangia biseriate, cylindrical, about 40-50 μm long, 5-6 μm broad, aggregated on the upper surface of the thalli.
• Infertile hairs rare, usually longer than the sporangia.

Growth and development

The life cycle of C. sinuosa is an alternation of heteromorphic stages, without any sign of sexuality, with saccate macrothalli forming plurilocular zoidangia only. The swarmers formed by these macrothalli germinate into pseudodiscoidal or filamentous prostrate microthalli, which measure 1-3 mm in diameter in laboratory cultures. On these prostrate microthalli both unilocular and plurilocular zoidangia can develop, depending on culture conditions. Swarmers from these plurilocular zoidangia always grow into similar prostrate microthalli again, but the zoids from unilocular zoidangia grow into small pseudodiscs that become swollen and form the saccate macrothalli again. In this life cycle no sexual stages have been discerned, which differs from the situation in the related C. peregrina Sauv., where zoids from plurilocular zoidangia, formed on the macrothalli, can fuse to form zygotes. Thus the plurilocular zoidangia are gametangia in C. peregrina. The zygotes develop into prostrate microthalli, on which both unilocular and plurilocular zoidangia can be formed. Thus, in C. peregrina, the saccate macrothalli can be considered to be gametophytes, and the prostrate microthalli are sporophytes. Due to parthenogenesis, however, the complete life cycle in C. peregrina is more complicated.

Other botanical information

It is rather difficult to differentiate C. sinuosa from the related C. peregrina, which is, however, mainly a temperate alga.

Ecology

C. sinuosa is commonly found attached to rocky substrate in intertidal areas on reef flats to shallow subtidal zones, subjected to slow to moderate water movement. Its hollow bulbous thalli are generally bigger in size in calm areas than those in wave-exposed areas. The thalli are easily removed from the substrate by strong wave action and may be transported to reef flats or to the shore as drift materials.

Propagation and planting

C. sinuosa is not grown in phycoculture.

Prospects

It can be expected that C. sinuosa will also be used in the future by coastal communities for food, animal feed and fertilizer. It might also become a source of pharmaceutical compounds.

Literature

• Kogame, K., 1997. Life histories of Colpomenia sinuosa and Hydroclathrus clathratus (Scytosiphonaceae, Phaeophyceae) in culture. Phycological Research 45: 227-231.
• Kogame, K. & Yamagishi, Y., 1997. The life history and phenology of Colpomenia peregrina (Scytosiphonaceae, Phaeophyceae) from Japan. Phycologia 36: 337-344.
• Silva, P.C., Meñez, E.G. & Moe, R.L., 1987. Catalog of the marine benthic algae of the Philippines. Smithsonian Contributions to the Marine Sciences 27. 179 pp.
• Trono Jr, G.C. & Ganzon-Fortes, E.T., 1988. Philippine seaweeds. Technology and Livelihood Center. National Bookstore Inc., Manila, The Philippines. 330 pp.
• Stefanov, K., Bankova, V., Dimitrova-Konaklieva, St., Aldinova, R., Dimitrov, K. & Popov, S., 1996. Sterols and acylglycerols in the brown algae Colpomenia peregrina (Sauv.) Hamel and Scytosiphon lomentaria (Lyngb.) Link. Botanica Marina 39: 475-478.

Sources of illustration

Kogame, K., 1993. In: Hori, T. (Editor): An illustrated atlas of the life history of algae. Vol. 2. Brown and red algae. Uchida Rokakuho Publishing Company, Tokyo, Japan. Fig. 31, p. 62 (diagram and zoid); Schneider, C.W. & Searles, R.B., 1991. Seaweeds of the southeastern United States. Duke University Press, Durham, United States. Fig. 169-171, p. 147 (habit, sections). Redrawn and adapted by P. Verheij-Hayes.

Authors

• G.C. Trono Jr