Gracilaria eucheumatoides Harv.

Gracilaria eucheumatoides Harv.





Vernacular Names

Indonesia Duyung (Bangka, Lingga).
Philippines Canot-canot (Ilokano), caocaoyan, cawat-cawat.

Geographical Distributions

Gracilaria eucheumatoides is found along tropical and subtropical coasts in the Indian and Pacific Oceans. In Southeast Asia, it has been recorded from Burma (Myanmar), the eastern coast of Thailand, Vietnam, Malaysia, Indonesia, the Philippines and Papua New Guinea.


Gracilaria eucheumatoides is a greenish to purplish thallus, cartilaginous in texture, thick and fleshy, forming loose or thick prostrate clumps, measuring between 3.4-8 cm long and is attached to substrate by means of many haptera. The branching is irregular and it is dichotomous to alternate. The branches are flattened, irregular in width, measuring up to 1 cm broad and with coarse, sharp teeth or short marginal spines.

The medullary cells are 130-132 µm in diametre, and with cell walls 3-6 µm thick while cell transition to cortex cells (20-30 µm to 7-13.5 µm x 4.5-9.0 µm) is gradual. The elongated gland cells measure 15-20 µm x 35-50 µm. The tetrasporangia are cross-shaped, spherical, elongated in transverse section and measuring 24-40 µm in diametre. The cystocarps are spherical, rarely constricted at the base, with pericarp 215-365 µm thick and are differentiated into two layers.

Ecology / Cultivation

Gracilaria eucheumatoides occurs on rocks in the intertidal and subtidal zones in open seas or coral areas. It does not grow on soft substrates or in unattached populations.

Line Drawing / Photograph



  1. Plant Resources of South-East Asia No.15(1): Cryptogams: Algae.