Codium schmiederi P.C. Silva, F.F. Pedroche, M.E. Chacana

Codium schmiederi P.C. Silva, F.F. Pedroche, M.E. Chacana ( Figures 1 View Figure 1 and 2 View Figure 2 )

Thallus prostrate, pulvinate, with erect or repent portions branched irregularly or subdichotomously ( Figure 1 View Figure 1 ). Branches cylindrical or compressed, 3–12 mm wide at interdichotomies, 20 mm broad at dichotomies, intertwining, anastomosing, attached to substrate here and there; pulvinate portion 3–5 mm thick, spongy, adhering loosely to the substrate. Thallus easy to dissect, mature utricles cylindrical, (900–) 1000–1300 (–1800) µm long, (89–) 110– 190 (–390) µm in diameter. Utricles from adherent portion of thallus showing much reduced sympodial growth, resulting in groups of utricles, most with two septa, one for each medullary filament ( Figure 2A View Figure 2 ). Utricles of the branched portion of the thallus showing less compact growth ( Figure 2B View Figure 2 ). Apices truncate or slightly rounded with thin walls (no more than 2–4 µm in thickness). Hairs (or hair scars) common in zone 110–280 µm below apex. Medullary filaments 30–60 µm diameter. Gametangia fusiform or lanceolate, (150–) 210–300 (–350) µm long, (45–) 60–90 (–120) µm diameter, several per utricle borne on cylindrical pedicel 15–30 µm long in zone 330–540 µm below apex.

Holotype

Isla Guadalupe, Baja California, Mexico, on shore, 2.5 miles N of South Bluff, E. Y. Dawson 8518, 20.xii.1949 ( UC 1718021 ). Isotype at US ( USNM 230805 About USNM ) ( Figure 1 View Figure 1 ).

UC specimens and label information may be viewed by entering the collection number at: //ucjeps.cspace. berkeley.edu/ucjeps_project/public/publicsearch/.

Specimens examined

Isla Guadalupe: UC 1718024, AHFH 79209 in UC ( UC 1831543), UC 1718018, UC 1718019, UC 1718020, AHFH 72024 in UC ( UC 1831545). Rocas Alijos: UC 1946216, UC 1946217.

Codium schmiederi is dimorphic in habit, with a prostrate base from which upright or repent axes arise. The utricles are also dimorphic, differing in basal and upright portions ( Figure 2A, B View Figure 2 ). This morphological and anatomical dimorphism is unique among known species of Codium .

In Codium , all primary utricles are formed by enlargement of deflected apices of sympodially growing filaments. In most species, the development of secondary utricles follows one of two paths. In erect dichotomously branched thalli, primary utricles produce additional utricles by emitting basally a filament that grows periclinally, enlarging terminally, and deflecting anticlinally to form a new utricle. A plug is always formed at or very close to the point of origin of the filament. (For examples, see Silva and Womersley 1956, figs. 8–16; Silva 1959, figs. 10–21.)

In C. schmiederi , by contrast, the adherent portion of the thallus, which initially resembles a thallus of Codium hubbsii , does not produce “families” of utricles typical of adherent species. Instead, small groups of utricles result from greatly reduced sympodial growth in which interutricular filaments are eliminated. Perversely, the intertwining branches produce small groups of utricles resembling families typical of adherent species.

The pattern of utricle formation described above as being typical of Codium has many exceptions, depending on the length of the interutricular filament. The pattern most closely similar to that of C. schmiederi is that of Codium coralloides (Kützing) P.C. Silva. In that species, however, the branches are rudimentary. In Codium pelliculare P.C. Silva (1959) , in which the thallus is membraniform, secondary utricles bud off the lower or middle portion of an existing utricle, but most do not develop rhizoids. In Codium picturatum F.F. Pedroche et P.C. Silva (1996) , which has an extremely thin adherent thallus with a tightly woven medulla, some interutricular filaments are so short that clusters of secondary utricles are formed. In some parts of the thallus, the distribution of secondary utricles, interutricular filaments, and plugs is chaotic ( Pedroche and Silva 1996, figs. 3, 4).

Previous records: as C. schmiederi Silva ined. in Schmieder (1996: 235); as C. schmiederi Silva, Pedroche et Chacana ined. in Pedroche et al. (2002: 30, figs. 24–28), Pedroche et al. (2005: 76).

In 1952, after returning from an expedition to islands off the coast of Baja California on board the RV Orca, Silva undertook a study of the collections of Codium and intended to name this species Codium seftonii in honor of Joseph W. Sefton, Jr., a San Diego banker and owner of the ship. Prior to the publication of this species, however, Mr. Sefton died. The intended honor was transferred to Robert W. Schmieder, the remarkably enterprising explorer who organized the expedition to Rocas Alijos.