Sargassum ulixei G. Andrade-Sorcia & S.M. Boo, 2014

Andrade-Sorcia, Gabriela, Riosmena-Rodríguez, Rafael, Muñiz-Salazar, Raquel, López-Vivas, Juan Manuel, Boo, Ga Hun, Lee, Kyung Min & Boo, Sung Min, 2014, Morphological reassessment and molecular assessment of Sargassum (Fucales: Phaeophyceae) species from the Gulf of California, Mexico, Phytotaxa 183 (4), pp. 201-223 : 212-214

Sargassum ulixei G. Andrade-Sorcia & S.M. Boo , sp. nov. ( Fig. 4 )

Thalli with a disc, crustose or conical holdfast. Stipe cylindrical and smooth, blades lanceolate to elliptic, sessile, 1–5 mm in length and 1.0– 2.5 mm wide. Nerve expanded, ecostate or faint, with smooth margins. Cryptostomata present. Vesicles elliptical, with smooth margins, sessile, 1–5 mm in length. The apical part of the vesicle has a short apicula. Receptacles cylindrical to elliptical, with smooth margins> 5 mm in length, growing in bunches with blades. Thalli up to 40 cm in length, with terete axes and smooth primary axes arising from the stipe, giving rise to numerous secondary branches. Secondary branches 5 cm in length in some thalli.

Type:— MEXICO. Sonora: Las Conchas. Attached to rocks in the subtidal zones. G. Andrade-Sorcia & R . Riosmena-Rodriguez, 14 May 2010 (holotype: FBCS! 12654, isotypes: HFBCS! 12655, 12656) .

Etymology:— The species epithet ‘ ulixei ’ refers to the character in Homer’s Odyssey, giving credit to the long trips and difficulties encountered when studying the Sargassum taxonomy.

Habitat:— Growth was observed on rocks in the intertidal zone.

Current distribution:— Kino Bay , Puerto Peñasco (Sonora) .

Remarks:— Specimens of this species were previously identified as S. johnstonii in the field. After detailed morphological assessment we found that these specimens shared some characteristics with both S. lapazeanum and S. johnstonii , suggesting that these specimens belong to the same section; also there are some similar morphologies. In East Asia, Kuntze (1880) reported some specimens similar to S. thunbergii (Mertens ex Roth 1800: 104) Kuntze (1880: 215 , 228); however, specimens from the Gulf of California were different and none of the characteristics could be applied to characterize the 25 specimens collected prior to molecular analysis. Both molecular and morphological analyses indicated that these specimens belong to a distinct entity which we propose to describe as a new species under the name S. ulixei .

Section Horridum G. Andrade-Sorcia & S.M. Boo, sect. nov.

Heterotypic synonym: group Sinicola Dawson (1944: 245)

Thalli with wood-like holdfasts initially discoid and becoming conical or hapteroid. The stipe and branches are cylindrical with spiny (muricate) margins. Leaf-like blades lanceolate, mostly 30–60 mm long, and 3–8 mm wide. Some blades are undulated, with a prominent nerve serrated margins, and numerous cryptostomata. Vesicles spherical, smooth, or spiny, 3.0– 4.5 mm in diameter. Cryptostomata could be observed on the vesiclesand the thallus. Receptacles cylindrical, with multiple branches, showing spiny or smooth margins, growing from the middle part of the thallus to the apical side. Thalli reached up to 60 cm in length, rigid and densely branched.

Type:— Sargassum horridum Setchell & Gardner (1924: 734) .

Habitat:— Growth was observed on rocks or calcareous substrates (as shells) in the intertidal or subtidal zone, some thalli were growing in intertidal pools.

Current distribution:— Gulf of California.

Remarks:— Dawson’s (1944) Sinicola group was described using characters from Setchell & Gardner’s first description for Sargassum horridum . We suggest to rename this group as section Horridum instead of Sinicola considering Sargassum horridum characters as the most representative. Note that group Sinicola Dawson (1944: 245) does not retain nomenclatural priority (ICN art. 37.3). This section is currently distributed along the Gulf of California.

Figures

FIGURE 4. Morphology of Sargassum ulixei sp. nov. A. Habit. B, C. Section of axial cells (a) and medullar cells (m). D. Holdfast. E. Sessile blades (arrow head), vesicles (arrow), and receptacles growing above the branch. F–H. Receptacles, zygote (z).