Codium (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Codium bartlettii - 1, habit; 2, utricles. C. arabicum - 3, habit; 4, cluster of utricles. C. geppiorum - 5, utricles. Codium sp. - 6, diagrammatic cross-section of a thallus branch.

Codium Stackh.

Protologue: Ner. britan.: 16, 24 (1797) [1795-1801].

Family: Codiaceae

Chromosome number: x= unknown; Atlantic C. tomentosum: 2n= 20

Major species and synonyms

• Codium arabicum Kütz., Tab. phycol. 6: 35, pl. 100. fig. 2 (1856), synonyms: C. coronatum Setchell (1926), C. coronatum var. aggregatum Børgesen (1940).

• Codium bartlettii C.K. Tseng & W.J. Gilbert, J. Wash. Acad. Sci. 32: 291-293, figs 1, 2a (1942).

• Codium edule P.C. Silva, in Egerod, Univ. Calif. Publ. Bot. 25: 392, Pl. 35b, fig. 18 (1952).

• Codium geppiorum O.C. Schmidt (as C. geppii), Bibl. Bot. 23 (91): 50, fig. 33 (1923), synonym: C. divaricatum A. Gepp & E. Gepp (1911).

• Codium harveyi P.C. Silva, in P.C. Silva & Womersley, Austr. J. Bot. 4: 277, fig. 11, Pl. 2 (1956).

• Codium intricatum Okamura, Icon. Jap. alg. 3: 74, pl. 120: figs 9-13 (1913) [1913-1915].

• Codium ovale Zanardini, Nuovo Giorn. Bot. Ital. 10: 37 (1878).

• Codium papillatum C.K. Tseng & W.J. Gilbert, J. Wash. Acad. Sci. 32: 293-295, figs 2b-d, 3 (1942).

• Codium tenue (Kütz.) Kütz., Tab. phycol. 6: 33, pl. 95, fig. 1 (1856), synonym: C. tomentosum (Huds.) Stackh. var. tenue Kütz. (1849). In the area covered here this is probably a misapplied name (including specimen names as C. muelleri Kütz.) for a yet undescribed species.

• Codium tomentosum (Huds.) Stackh., Ner. britan. 24, pl. 7 (1797) [1795-1801], synonyms: Fucus tomentosus Huds. (1797), Ulva tomentosa (Huds.) DC. (1805). This is an often used, but misapplied name. The species of this name only occurs in Atlantic Europe and North Africa. Most records for South-East Asia probably refer to such species as Codium bartlettii, C. geppiorum and C. "muelleri". The likewise misapplied name C. dichotomum (Huds.) A. Gray is often cited as a synonym.

Vernacular names

General:

• Codium
• Philippines: pupuklo, pocpolo, kinkintal.

C. arabicum

• Vietnam: rong-nhung arab.

C. geppiorum

• Indonesia: donge-donge (Sulawesi)
• Vietnam: rong-nhung gepp.

C. "muelleri"

• Philippines: popoklo (Ilocos), siling-siling, singling-singling (Visayas, Cebu).

C. "tenue"

• Philippines: pupu-lo
• Vietnam: rong-nhung min.

C. "tomentosum" (probably mainly C. geppiorum)

• Indonesia: susu lopek (Lombok), laur laur (Sulawesi)
• Philippines: ampalang
• Vietnam: rong-nhung lông.

Origin and geographic distribution

The 50-80 known species of Codium occur worldwide in tropical and warm temperate coastal waters, although a few species are known from colder waters. The distribution of the species listed (mainly in South-East Asia) is as follows:

• C. arabicum occurs in the Indian and Pacific Oceans; in South-East Asia in Burma (Myanmar), Thailand, Malaysia, Singapore, eastern Indonesia, the Philippines and the northern and southern coast of Papua New Guinea.
• C. bartlettii occurs in the Indian and Pacific Oceans; in South-East Asia in Indonesia (Sulawesi) and the Philippines.
• C. edule occurs in the Indian and Pacific Oceans; in South-East Asia in Indonesia (Sulawesi), the Philippines and the northern coast of Papua New Guinea.
• C. geppiorum occurs in the Indian and Pacific Oceans, throughout South-East Asia, and the northern coast of Papua New Guinea.
• C. harveyi occurs in Australia and New Zealand; in South-East Asia, it has been recorded in Indonesia (Sulawesi).
• C. intricatum occurs in the Pacific Ocean mainly in Japan; in South-East Asia it has been recorded in the Philippines.
• C. ovale is mainly recorded from the Indian Ocean, in the Pacific Ocean from the Marshall Islands; in South-East Asia it has been recorded in Malaysia, eastern Indonesia, the Philippines (Mindoro) and the southern coast of Papua New Guinea.
• C. papillatum was originally described from Mindoro (the Philippines), and has also been recorded in India, Kuwait and China.
• C. "tenue" is restricted to river estuaries of South Africa. The recorded specimens from the Philippines, Indonesia and Papua New Guinea probably belong to another (not yet described) species.
• C. "tomentosum" has been misapplied in naming specimens from Malaysia, Singapore, Indonesia and the Philippines.

Uses

In South-East Asia especially C. arabicum, C. bartlettii, C. edule, C. geppiorum, C. intricatum, C. "muelleri", C. ovale, C. papillatum, C. "tenue", and C. "tomentosum" are used, mainly in human food. C. bartlettii, C. geppiorum and C. edule in particular are eaten in Malaysia, Indonesia and the Philippines. They are either dried and preserved in ash or salt to be boiled in water to prepare soup or, alternatively, after washing or soaking in freshwater, the fresh or dried algae are mixed with soya bean sauce and vinegar to be eaten in salads. For the latter the algae must not be cooked or blanched, for they become soft and disintegrate quickly with heat. In Vietnam and Thailand several of these Codium spp. are listed as "algae of potential use", while in the Philippines especially C. edule has the potential to be widely used. Other uses of Codium in South-East Asia are in animal feed, as an insect repellant and as a vermifuge (anthelmintic properties). In Chinese herbal medicine Codium powder is used as a treatment against urinary diseases and dropsy.

Properties

Anthelmintic, antibacterial and antitumour properties have been recorded for Codium. Extracts of Codium spp. have shown some antibacterial activity against the growth of Staphylococcus and Streptococcus bacteria. The structural fraction of the cell walls in these algae consists of a mannan, while the amorphous matrix fraction is for the greater part arabinogalactan. In several Codium spp. a rich source of haemagglutinins (lectins) occurs. Some of these N-acetyl-α-D-galactosamine-binding lectins are now available commercially.

Description

• Mature thalli uncalcified, green, spongy, attached to the substrate by a disk or rhizoids over an extensive or limited area; unbranched (crustose, globular, foliose) or branched (repent, ascendent or erect); branching dense or lax, regularly or irregularly dichotomous or trichotomous; branches uniformly terete or (partly) compressed especially at the dichotomies; height varying from several mm in crustose species to about 1 m, in other regions even larger.
• Anatomically divisible into a central medulla, composed of intertwined siphonous filaments, and a single-layered cortex, composed of a surface layer of inflated photosynthetic vesicles (utricles).
• Dissociated filamentous stages occurring independently, forming a fibrous mat of siphonaceous, irregularly-branched filaments, often with young button-like growth of spongy differentiated thalli.
• Utricles in the spongy stages individual or in clusters, of various shapes and sizes, mostly clavate or cylindrical, but also capitate, obpyriform, orbiculate or wedge-shaped, with truncate, rounded, depressed, acute or mucronate apices, often bearing colourless hairs or hair scars; utricular wall mostly slightly or markedly thickened at the apices.
• Chloroplasts homoplastidic, without pyrenoids.
• Life cycle diplontic.
• Gametangia borne laterally on utricles, mostly oval, fusiform or elliptical, discharging anisogametes apically.

• C. arabicum. Thalli olive to dark green, crustose, not branched but with irregular lobes up to 10 cm long, 1-5 cm broad, tightly adhering to the substrate, becoming convoluted with age and developing orbicular, foliose excrescences 1-3 cm in diameter. Utricles in clusters; large primary utricles (sub)cylindrical to clavate, (700-)990-1120(-1300) μm long, (80-)180-230(-390) μm in diameter; hair scars common on older utricles (up to 20 per utricle); gametangia fusiform to elliptical.

• C. bartlettii. Thalli deep green to green-brown, erect, up to 18 cm tall, repeatedly irregularly subdichotomous-divaricately branched with very broad angles; branches terete to complanate, compressed at the dichotomies; branches adhering to each other at some points by cushion-like rhizoidal structures. Utricles individual, clavate or (sub)cylindrical, (400-)600-900(-1200) μm long, (60-)130-300(-600) μm in diameter; hairs common (1-10 per utricle); gametangia elliptical.

• C. edule. Thalli green to green-brown, repent, irregularly dichotomously branched; branches terete, 2-4 mm in diameter, intricate, with secondary attachments to the substrate, forming extensive mats up to 25 cm in diameter. Utricles individual, subcylindrical to clavate, (430-)700-900(-1100) μm long, (70-)130-270(-320) μm in diameter; hairs or hair scars usually present (1-10 per utricle); gametangia elliptical to ovoid.

• C. geppiorum. Thalli olive to dark green, repent, irregularly divaricately (sub)dichotomous; branches terete, anastomosing, about 3 mm in diameter, attached to the substrate by means of rhizoids at several places. Utricles individual, clavate, elongate obpyriform, (sub)cylindrical or orbiculate, (300-)450-620(-850) μm long, (50-)100-200(-300) μm in diameter in the widest part; hairs or hair scars 0-3(-4) per utricle; gametangia fusiform, with or without a nozzle, 1-2(-3) per utricle.

• C. harveyi. Thalli medium green, erect, dichotomous, up to 30 cm tall; branches terete, 3-5 mm in diameter. Utricles individual, short and irregularly swollen, 340-850 μm long, 170-600 μm in diameter, apices broadly rounded; hairs frequent; gametangia elongate-ovoid, 1-4 per utricle.

• C. intricatum. Thalli dark green, repent, mat-like, divaricately dichotomous, attached to the substrate by very fine rhizoids; branches short, terete, intricate. Utricles individual, cylindrical or clavate, (100-)120-540(-560) μm long, (80-)90-210(-230) μm in diameter; hairs absent; gametangia unknown.

• C. ovale. Thalli dark green, oval to subspherical, fully grown specimens hollow, erect, adhering to the substrate with the pointed part, up to 12-16 mm tall, 10-12 mm wide. Utricles individual, clavate or (sub)cylindrical, (470-)600-750(-1050) μm long, occasionally 1060-1220 μm, (155-)230-280(-400) μm in diameter; hair scars absent or occurring in one row at the apices of the utricles; gametangia elliptical to oblong.

• C. papillatum. Thalli green, erect, subdichotomous, up to 10 cm tall, arising from a spongy rhizoidal mass; branches of young specimens subterete and becoming complanate when old, dichotomies about 1 cm broad. Utricles individual, subcylindrical or obovoid, some with a few conical papillae, (600-)650-850(-900) μm long, 100-300 μm in diameter, apical wall thickened, 10-33 μm thick, markedly stratified and foveolate; hairs present; gametangia elliptical or ovoid.

• C. "tenue". Thalli light green, erect, up to 45 cm tall, divaricately (sub)dichotomous, interdichotomies terete, 4-6 mm in diameter, dichotomies compressed. Utricles individual, clavate, obpyriform or cylindrical, (300-)400-600(-800) μm long, (90-)135-400(-500) μm in diameter; hairs frequently present (1-5 per utricle); gametangia elliptical or ovoid.

• C. "tomentosum". Thalli dark green, erect, 5-40 cm tall, repeatedly, regularly or irregularly dichotomous; branches terete but occasionally compressed at the dichotomies. Utricles individual, cylindrical, clavate or elongate obpyriform, (450-)600-700(-850) μm long, (80-)100-200(-300) μm in diameter; hair scars present (1-5 per utricle); gametangia ovoid, elliptical or fusiform.

Growth and development

The life cycle of Codium is considered to be diplontic, with a zygote developing into a diploid gametophyte; meiosis probably occurs in the gametangia. Male gametangia are yellowish, forming tiny biflagellate male gametes. The female gametangia, however, are dark green and divide into much larger biflagellate gametes, each containing many chloroplasts. Codium has traditionally been considered to have gametic meiosis, but the evidence for this is not yet convincing. It has not yet been possible to obtain fully grown spongy plants in culture. Growth of dissociated filamentous stages is possible in laboratory culture.

Other botanical information

The Codium plants can be regarded as multi-nucleate unicellular organisms, although the coenocytic tubes are subdivided into compartments by rings of cell wall material (perforated cellulosic plugs). Only the gametangia are separated by real cross-walls from the rest of the thallus.

Ecology

Codium can be epilithic, epipsammic, epiphytic or rarely even epipelic.

• C. arabicum. Epilithic, mainly on vertical and overhanging rock walls of reef pools in the lower intertidal zone; epiphytic on stipes of larger seaweeds and on stems of seagrasses in low intertidal or high subtidal zones of sandy lagoons.

• C. bartlettii. Epipsammic or epilithic, growing on subtidal coral reefs, down to 10-15 m depth.

• C. edule. Growing on reef flats (epilithic), in lower intertidal habitats, and in sandy tide pools (epipsammic).

• C. geppiorum. Epilithic on vertical and overhanging rock walls, sometimes epipsammic, in the lower intertidal and subtidal zones.

• C. harveyi. In the subtidal zone, down to 30 m depth.

• C. intricatum. In the lower parts of the intertidal and subtidal zones, mainly on rocks and overhangs, also on sandy coral substrate.

• C. ovale. On subtidal coral reefs or rocks (epilithic), occasionally epipsammic or on the stems of seagrasses in areas well-exposed to moderate to strong water currents. It occurs down to 10-30 m deep.

• C. papillatum. On lower intertidal coral reefs.

• C. "tenue". On reefs (epilithic) or on sandy substrate (epipsammic).

• C. "tomentosum". Epipsammic or epiphytic on seagrasses (epiphytic).

Propagation and planting

Codium is not grown in phycoculture.

Harvesting

Codium is only hand-collected from natural populations.

Handling after harvest

Codium is sold and used fresh, sun-dried, or preserved in salt or ash.

Prospects

Some of the marine algal lectins are much smaller than those derived from land plants. This characteristic alone may make the algal lectins more suitable for uses such as drug targeting, than those derived from land plants, because the smaller molecules might be expected to be less antigenic. This might result in a growing commercial interest in algal lectins, including Codium spp.

Literature

• Pramudji, 1992. Seaweeds of the Snellius-II Expedition (East Indonesia): the genus Codium (Chlorophyta, Codiales). MSc. Thesis, Vrije Universiteit Brussel, Belgium. 60 pp.
• Schmidt, O.C., 1923. Beiträge zur Kenntnis der Gattung Codium Stackh. [Contribution to the knowledge of the genus Codium Stackh.]. Bibliotheca Botanica 23 (91): 1-68.
• Silva, P.C., 1952. Codium. In: Egerod, L.E. (Editor): An analysis of the siphonous Chlorophycophyta, with special reference to the Siphonacladales, Siphonales and Dasycladales of Hawaii. University of California Publications in Botany 25(5): 381-395.
• Tseng, C. & Gilbert, W., 1942. On new algae of the genus Codium from the South China Sea. Journal Washington Academy of Sciences 32(10): 291-296.
• Van den heede, C. & Coppejans, E., 1996. The genus Codium (Chlorophyta, Codiales) from Kenya, Tanzania (Zanzibar) and the Seychelles. Nova Hedwigia 62: 389-417.
• Yang, M.-H., Blunden, G., Huang, F.-L. & Fletcher, R.L., 1997. Growth of a dissociated, filamentous stage of Codium species in laboratory culture. Journal of Applied Phycology 9: 1-3.

Sources of illustration

Original illustrations made by the authors (utricles of C. arabicum, C. geppiorum); Smith, G.M., 1938. Cryptogamic botany. Vol. 1. Algae and fungi. McGraw-Hill Book Company, New York, United States. Fig. 58, p. 112 (cross-section); Trono, G.C. & Ganzon-Fortes, E.T., 1988. Philippine seaweeds. National Bookstore, Manila, The Philippines. Figs. 26 & 27, pp. 45, 46 (habits C. arabicum, C. bartlettii, utricles C. bartlettii). Redrawn and adapted by P. Verheij-Hayes.

Authors

• E. Coppejans, C. Van den heede & W.F. Prud'homme van Reine