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New growth of Codium reediae attached to basalt rock
reef flat subtidally.
Codium reediae, or limu a‘ala‘ula, is
a common edible seaweed found
subtidally on Hawaiian reef flats.
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.
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
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
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.
1999. Marine Red Algae of the Hawaiian Islands. Bishop Museum Press,
1961. A possible invader of the marine flora of Hawai‘i. Pacific Science
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.
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.
and Mark M., 2000. Caribbean Reef Plants. OffShore Graphics, Washington,
and J. Hunt, 1979. Seaweeds of Hawai‘i. Oriental Publ. Co., Honolulu,
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.
Ecological Success of Alien/Invasive Algae in Hawai‘i:
Marine Invasives in Hawai‘i:
The Indian River Lagoon Species Inventory: