UC specimens and range limits for Codium setchellii

• Blue markers: specimen records
• Yellow marker: type locality, if present
• Red markers: endpoints of range from literature

View map from the Consortium of Pacific Northwest Herbaria

Status: Confirmed by sequence from Seppings Is., British Columbia, Canada; La Bufadora, Baja California, Mexico (Verbruggen et al. 2007). Difficult to distinguish from C. hubbsii in subtidal southern California.

Habitat: Low intertidal, associated with sand; sometimes subtidal in southern California

Life History: Not investigated, but probably with a perennial diploid macroscopic thallus producing anisogametes, zygote developing into pancake-like stage from which gametophyte eventually arises (Borden and Stein 1969; Smith 1930); parthenogenesis possible.

Search Sequences in GenBank

Illustration from DeCew's Guide to the Seaweeds of British Columbia, Washington, Oregon, and Northern California

Codium Stackhouse 1797

Thalli much branched, the branches compacted and forming erect or prostrate, noncalcareous spongy thallus of definite form, basally attached by rhizoids. Surface layer composed of palisade-like, photosynthetic, enlarged branch tips (utricles). Interior of thallus composed of slender, colorless, intertwined tubular branches. Thalli mostly dioecious; gametangia fusiform to cylindrical, borne laterally on utricles and sealed off at base by annular thickenings. Gametes biflagellate, anisogamous, formed following meiosis. Zygote developing directly into diploid plant.

Codium setchellii Gardn.

Gardner 1919: 489; Setchell & Gardner 1920b: 168; Smith 1944: 75; Silva 1951: 83.

Thalli prostrate, pulvinate, forming indefinitely expanded, dark green, firm, irregular cushion to 25 cm broad (or broader by coalescence), 6-15 mm thick, often coarsely rugose, closely adherent to substratum; utricles abundantly branched, cylindrical to narrowly clavate, mostly 65-90 µm diam., 0.65-1 mm long; utricle wall to 16 µm thick and lamellate at apex, but not internally sculptured.

Frequent on exposed rocks, low intertidal, from Sitka, Alaska, throughout Wash. and Calif. to Pta. Baja, Baja Calif. Type locality: Pacific Grove, Calif.

Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.

Notes: This species is one of several adherent forms distinguished from one another by anatomical characters. On the Pacific coast of North America, the only adherent species other than Codium setchellii is Codium hubbsii, which is readily distinguished by utricles that frequently bear hairs and have apical walls that are usually at least slightly alveolate. In contrast, the utricles of Codium setchellii are distinguished by the lack of hairs or hair scars and by their smooth, unornamented apical walls (see Illustrations). Whereas C. setchellii survives cold water as far north as Sitka, Alaska, and thrives in upwelling areas in Baja California as far south as Punta Baja (Dawson 1953: 109), C. hubbsii requires a higher optimal temperature. On the mainland of California, C. setchellii usually grows on the sides of boulders partly buried in sand, in the lowest intertidal zone. The thallus forms a tightly adherent carpet that spreads out in all directions. The advent of scuba, however, has led to the discovery of a subtidal adherent Codium that is anatomically indistinguishable from the intertidal form. According to Dawson et al. (1960a,b), C. hubbsii and C. setchellii are common inhabitants of kelp beds in Baja California at depths of 9-23 m, where they have the same habit and habitat and are macroscopically indistinguishable.