Caloglossa leprieurii (PROSEA)
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Introduction |
Caloglossa leprieurii (Mont.) G. Martens
- Protologue: Flora 52: 234 (1869).
- Family: Delesseriaceae
- Chromosome number: n= 30, 2n= about 60
Synonyms
- Delesseria leprieurii Mont. (1840),
- Caloglossa mnioides Harv. ex J. Agardh (1876),
- C. leprieurii var. hookeri E. Post (1936).
Vernacular names
- China: zhegucai (as medicine).
Origin and geographic distribution
C. leprieurii is widely distributed in tropical and warm temperate waters, throughout the Atlantic, Indian and Pacific Oceans. In South-East Asia it has been recorded in Burma (Myanmar), Thailand, Peninsular Malaysia, Singapore, Indonesia, Brunei, the Philippines, and northern Papua New Guinea.
Uses
References to the use of C. leprieurii as food (for salad and vegetable soup) are scattered in the literature and may refer to other Caloglossa spp. as well, particularly C. bengalensis (Martens) R.J. King & Puttock and C. adhaerens R.J. King & Puttock (as C. adnata sensu E. Post). In traditional Chinese medicine and also in Vietnam, C. leprieurii is used as a vermifuge, and was known as long ago as 1530 A.D. under the name zhegucai. In modern Chinese medicine zhegucai usually refers to another red alga, i.e. Digenea simplex (Wulfen) C. Agardh. In Indonesia C. leprieurii is used in the treatment of goitre, urinary diseases and dropsy.
Production and international trade
In southern China C. leprieurii is sold on markets in the form of circular sheets of about 10 cm in diameter.
Properties
Caloglossa spp. synthesize the organic osmolyte mannitol, a polyol (hexitol) unknown in other red algae. It acts as a compatible solute and as a regulator for metabolic control occurring during growth under the extremes of salinity encountered in the mangrove habitat. The compound responsible for the vermifugous properties is still unknown.
Description
- Thalli spreading, erect in some portions, reddish-violet, reddish-brown to pale-brown; blades strap-shaped, thin, membranous, 1-3 mm across, occasionally arising in rosettes from a stipe, alternately branched and forked at the apices, constricted, often with rhizoids at the constrictions (nodes); internodal segments elongate-ovate to linear-lanceolate, 1-4 mm long, composed of a midrib of large rectangular cells and lateral blade; secondary branches or segments - leaflike, proliferous from the forkings or midribs of blades, with small subhexagonal cells in oblique series from the midrib to the margin.
- Life cycle triphasic, diplo-haplontic and isomorphic.
- Tetrasporangia spherical, (23-)50-75 μm in diameter at maturity, in oblique series near upper portion of blade, with a cover cell on both blade surfaces; each sporangium forming four tetraspores.
- Gametophytes dioecious, rarely monoecious; procarps on ventral surface of internodes, sometimes also dorsally, at times on both surfaces; cystocarps ostiolate; spermatangial sori on blades at both sides of midrib and on both surfaces of terminal and subterminal segments.
Growth and development
In C. leprieurii growth is by a dome-shaped apical cell, which cuts off segments by transverse division. Each segment cell undergoes division into a central cell and four pericentral cells, of which the lateral ones give off oblique rows of cells that form the monostromatic wings of the thalli. Tetrasporophytes of C. leprieurii are much more common than gametophytes. Procarps are produced in acropetal succession by transverse pericentral cells in the terminal parts of the thalli. After fertilization of the carpogonia of the procarps, cystocarps develop formed by cortical cells of the female gametophytes.
Other botanical information
Much that is reported about distribution, uses and properties of C. leprieurii also applies to other Caloglossa spp., in particular to C. adhaerens. In C. leprieurii attachment is by rhizoids that arise from scattered and isolated cells of the wings. In C. adhaerens, however, rhizoids are grouped together and arise from the nodes. The status of C. leprieurii var. hookeri is still under discussion. In some modern revisions this variety is not recognized, while in others it is considered morphologically and genetically distinct.
Ecology
C. leprieurii is a tropical or warm-temperate alga often associated with mangrove vegetation, where it grows on the modified roots and bases of mangrove plants. In these habitats it occurs in a characteristic mixed community with other Caloglossa spp. and with red algae such as Bostrychia spp., Catenella spp. and Stictosiphonia spp. This community is characteristic of mangrove habitats and is generally referred to as the Bostrychia-Caloglossa association. The algae of this association do not appear to be heavily grazed and the algal production is assumed to enter the food web through detrital food chains. The relative contribution of algae to the overall productivity of the mangrove community is unknown. Many fish and crustaceans feed among mangroves and this has implications for the drainage and the so-called "reclamation" of mangrove swamps, especially where there is a heavy reliance on inshore fisheries. C. leprieurii also occurs epilithically on fully marine coasts, but is more common in estuaries near the lower limits of salinity influence. It is also recorded in permanent freshwater habitats. Its capacity to grow in a range of salinities, and to cope with fluctuating salinities, has frequently been investigated.
Propagation and planting
C. leprieurii is not grown in phycoculture.
Harvesting
Field material of C. leprieurii is only hand-collected.
Handling after harvest
C. leprieurii is collected for direct consumption or dried for medicinal use.
Prospects
Caloglossa spp. are the only red algae producing mannitol. However, this compound is much more common in brown seaweeds and its extraction from Caloglossa thalli is most probably not commercially viable. If the compound responsible for the vermifugous properties can be isolated, the use of C. leprieurii for fine chemicals may be promising.
Literature
- Istini, S., Zatnika, A. & Sujatmiko, W., 1998. The seaweed resources of Indonesia. In: Critchley, A.T. & Ohno, M. (Editors): Seaweed resources of the world. Japan International Cooperation Agency, Yokosuka, Japan. pp. 92-98.
- Karsten, U., Barrow, K.D. & King, R.J., 1998. Mannitol metabolism of the epiphytic mangrove red alga Caloglossa leprieurii (Ceramiales): a long-term field study. Phycological Research 46: 91-96.
- Karsten, U., Barrow, K.D., West, J.A. & King, R.J., 1997. Mannitol metabolism in the intertidal mangrove red alga Caloglossa leprieurii: salinity effects on enzymatic activity. Phycologia 36: 150-156.
- King, R.J. & Puttock, C.F., 1994. Morphology and taxonomy of Caloglossa (Delesseriaceae, Rhodophyta). Australian Systematic Botany 7: 89-124.
- Papenfuss, G.F., 1961. The structure and reproduction of Caloglossa leprieurii. Phycologia 1: 8-31.
- Post, E., 1936. Systematische und pflanzengeographische Notizen zur Bostrychia-Caloglossa Assoziation [Notes on the systematics and plant-geography of the Bostrychia-Caloglossa association]. Revue Algologique 9: 1-84.
- Tjon Sie Fat, L.A., 1976. Bostrychietum, plantengeografisch onderzoek over de Bostrychia-Caloglossa-gemeenschap, de algenformatie van de mangrovebossen [Bostrychietum, a plant-geographic study on the Bostrychia-Caloglossa association, the algal formation of the mangrove forests]. MSc. Thesis, Rijksherbarium, Leiden University, The Netherlands. 115 pp.
Sources of illustration
Børgesen, F., 1919. The marine algae of the Danish West Indies, Part 3: Rhodophyceae (5). Dansk Botanisk Arkiv 3(1): Fig. 338, p. 342 (habit); Papenfuss, G.F., 1961. The structure and reproduction of Caloglossa leprieurii. Phycologia 1: Fig. 30, p. 23 (detail of tetrasporangia); Tanaka, J. & Chihara, M., 1985. Taxonomic studies of Japanese mangrove algae 2. Two taxa of Caloglossa (Ceramilales, Rhodophyceae). Bulletin of the National Science Museum, Series B (Botany) 11(2): Fig 3, p. 46 (tetrasporangial thalli, cystocarpic thallus, spermatangial thalli). Redrawn and adapted by P. Verheij-Hayes.
Author
- W.F. Prud'homme van Reine
