University of Hawai`i

Botany Department

          Marine Algae of Hawai`i

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Codium reediae  (limu a‘ala‘ula) 

Silva in Egerod 1952




Class Order Family
Chlorophyta Chlorophyceae Bryopsidales Codiaceae

Click on picturees for larger images


New growth of Codium reediae attached to basalt rock on
shallow reef flat subtidally.



Codium reediae, or limu a‘ala‘ula, is
a common edible seaweed found
subtidally on Hawaiian reef flats.















Clumps of Codium reediae (lower front) on reef flat.



Thallus is fleshy, erect, composed of somewhat flattened fronds arising from a single discoid holdfast. Fronds are from 1 - 2 cm wide, slightly flattened in lower half, and markedly flattened in upper half. Branching is primarily irregularly dichotomous, expanding above to cuneate, flattened dichotomies at ends of fronds.


Codium reediae, like other Codium species, is soft, velvety and spongy to the touch.  Color is commonly dark green.


Structural Features

Medullary filaments mostly 26-46 µm diameter, one to several filaments arising from base of each utricle by slender outgrowth, forming a sharp demarcation between utricle and filament. Utricles are long (400-1000 µm) and wide (130-400 µm), many are conical-shaped with a thickened apex wall. These utricles usually have a short bulbous hair or extremely long (2500 µm) hairs attached, with a darkened swollen tip. Gametangia ellipsoidal, elongate-ellipsoidal, or at times ovate, 80-130 µm diameter, 260-330 µm long, borne on short but distinct pedicel at or just above middle of utricle, 1-3 per utricle, extending approximately to apex of utricle.



Codium reediae forms erect, dark green upright plants attached to the substrate with a single holdfast. Found subtidally on reef flats and in tidepools.  Do not confuse this species with C. edule, which lies prostrate and is attached to the substrate by rhizoids in numerous places along the thallus.



Hawai‘i:  O‘ahu, Mau‘i, Kau‘i.

Mechanism of Introduction: Indigenous to Hawai‘i.

Worldwide:  South Pacific and Indian Ocean.



Codium reediae is a common shallow subtidal green algae that feels and looks like velvet. This species is fairly scattered on the reef flat, and does not usually form dense communities but more often occurs as discrete, single plants. Codium species are part of the Hawaiian green turtle’s (Chelonia mydas) diet.


C. reediae is also a popular edible seaweed gathered for market in Hawai‘i. It is known by the Hawaiian name limu a‘ala‘ula, but is occasionally referred to as limu wawae‘iole, the name more often used for C. edule.


Abbott, I.A., 1999. Marine Red Algae of the Hawaiian Islands. Bishop Museum Press, Honolulu, Hawai‘i.

Doty, M., 1961. A possible invader of the marine flora of Hawai‘i. Pacific Science 15: 547-552.

Kilar, J.A. and J.L. McLachlan, 1986. Ecological studies of the alga, Acanthophora spicifera (Vahl) Břerg. (Ceramiales: Rhodophyta): Vegetative fragmentation. J. Exp. Mar. Biol. Ecol., 104: 1-21.

Kilar, J.A. and J.L. McLachlan, 1988. Composition, export, and import of drift vegetation on a tropical, plant-dominated, fringing-reef platform (Caribbean Panama). Coral Reefs, 7: 93-103.

Littler, D.S. and Mark M., 2000. Caribbean Reef Plants. OffShore Graphics, Washington, D.C.

Magruder, W.H. and J. Hunt, 1979. Seaweeds of Hawai‘i. Oriental Publ. Co., Honolulu, Hawai‘i.

Russell, D.J., 1992. The ecological invasion of Hawaiian reefs by two marine red algae, Acanthophora spicifera (Vahl) Břerg. and Hypnea musciformis (Wulfen) J.Ag., and their association with two native species, Laurencia nidifica and Hypnea cervicornis J.Ag. ICES Mar. Sci. Symp., 194: 110-125.

Russell, D. J. and G. H. Balazs. 2000. Identification manual for dietary vegetation of the Hawaiian green turtle, Chelonia mydas. NOAA TM-NMFS-SWFSC-294. 49 pp.


 Web Pages

Ecological Success of Alien/Invasive Algae in Hawai‘i:

Marine Invasives in Hawai‘i:

The Indian River Lagoon Species Inventory:



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