Udotea unistratea D.S. Littler & M.M. Littler 1990: 240

Acosta-Calderón, Julio Adulfo, Hernández-Rodríguez, César, Mendoza-González, Ángela Catalina & Mateo-Cid, Luz Elena, 2018, Diversity and distribution of Udotea genus J. V. Lamouroux (Chlorophyta, Udoteaceae) in the Yucatan peninsula littoral, Mexico, Phytotaxa 345 (3), pp. 179-218 : 208

Udotea unistratea D.S. Littler & M.M. Littler 1990: 240

Type Locality:— BELIZE. On the east side of Carrie Bow Cay.

Morphology:—Thalli to 9 cm tall, anchored to the substrata by a small compact mass of rhizoids siphons. Stipe cylindrical, 6–18 mm length, 3–4 mm wide. There is an evident transition between stipe and blade. Blade fan-shaped flat, delicate, longer (2–7.5 cm) than wider (2.5–9 cm), light green, lower margin acute, unistratose, ecorticate, slightly calcified and faint concentric lines present (Fig. 77).

Anatomy:—Blade siphons without lateral appendages, dichotomously branched, 30–60 μm in diameter (Fig. 78), distance between each dichotomy varies from 2000 to 8000 μm, supradichotomic constrictions 20–30 μm length, 20– 25 μm in diameter ( Fig. 79 ). Stipe siphons adjacent to lateral appendages 50–80 μm in diameter, appendages peduncle 120–300 μm length, 30–40 μm in diameter. Appendages dichotomously branched twice, constriction at the base and terminating in short dichotomously lobed, blunt tips ( Fig. 80 ).

Reproduction:—Vegetative

Material examined:— MEXICO. Quintana Roo, Chankanab, Isla Cozumel, 15 May 1993, R. B. Searles, M. Volovseck, ENCB 12797. MEXICO. Campeche, Don Lin, 22 June 2004. P. López, ENCB 19107.

Geographic distribution:—Florida, Belize, Bahamas, Cuba, Jamaica, Puerto Rico, Virgins Islands, Mexico

Habitat:—Sandy bottom, subtidal to 7–15 m depth.

Comments:—Blade characteristics and the shape of stipe lateral appendages of reviewed specimens correspond to those described for Udotea unistratea by Littler & Littler (1990). The diameter of blade and stipe siphons is less than those recorded in specimens from Bahamas, Jamaica, Belize ( Littler & Littler 1990), Isla Cozumel ( Collado-Vides et al. 2009) and Puerto Rico ( Ballantine et al. 2011). Udotea unistratea can closely resemble the morphology of Udotea cyathiformis but is clearly distinguished by the unistratose blade and the shape of stipe appendages. Apparently, this species is distributed in the coast of Campeche and Quintana Roo at depths greater than 7 m. Littler & Litler (1990) reported that this specie occurs in deep water (to 46 m). Recently Ballantine et al. (2011) record U. unistratea to 70 m of deep.

Figures

FIGURES 79–80. U. unistratea. 79) detail of the supradichotomic constriction 80) stipe lateral appendage.FIGURES 81–84. U. wilsonii. 81) external morphology, 82) upper portion of the blade siphons, 83) blade lateral appendages, 84) stipe lateral appendages.