Udotea norrisii D.S. Littler & M.M. Littler 1990: 235

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 : 204-206

Udotea norrisii D.S. Littler & M.M. Littler 1990: 235

Type Locality:— BAHAMAS. Chub Cay, Andros Reef.

Morphology:—Thalli to 8.5 cm tall, anchored on substrata by a bulbous mass of entangled rhizoidal siphons. Stipe cylindrical, heavy calcified, 6–15 mm long, 3–6 mm in diameter, transition between the stipe and blade is not evident. Blade flabellate o spatulate, green, the blade can be as long as wide or longer than wider, with longitudinal proliferations, lower margin ovate o truncate, multistratose, corticated (with lateral appendages), heavily calcified, and clearly zonate (Fig. 65, 66).

Anatomy:—Blade siphons with lateral appendages, dichotomously branched, 20–30 μm in diameter, siphons possess wide and irregularly spaced lateral appendages(Fig. 67), tightly adherent at the tips, appendages peduncle 90–120 μm length, 13–18 μm in diameter, with short swollen and flat dichotomously apices. Stipe siphons adjacent to lateral appendages 25–45 μm in diameter, appendages peduncle 100–160 μm length, 19–25 μm in diameter, appendages dichotomously branched 1–2 times, with swollen tips (Fig. 68).

Reproduction: — An indication of the presence of sexual reproductive structures is the development of a darkened region in the distal portion of the blade, these structures are tubular extensions of the siphons (Fig. 69).

Material examined:— MEXICO. Quintana Roo. Punta Rio Bermejo, 12 April 2015, J. A. Acosta-Calderón, L. E. Mateo-Cid, A. C. Mendoza-González, ENCB 23177. MEXICO. Quintana Roo, Punta Akumal, 16 December 2014, J. A. Acosta-Calderón, L. E. Mateo-Cid, A. C. Mendoza-González, ENCB 23175. MEXICO. Quintana Roo, Santa Rosa, 12 April 2015, J. A. Acosta-Calderón, L. E. Mateo-Cid, A. C. Mendoza-González, ENCB 23174. MEXICO. Campeche, Payucán, 23 October 2015, J. A. Acosta-Calderón, L. E. Mateo-Cid, A. C. Mendoza-González, ENCB 23176. MEXICO. Campeche, La Ensenada, 27 June 2016, J. A. Acosta-Calderón, L. E. Mateo-Cid, A. C. Mendoza-González, ENCB 23178.

Geographic distribution:— Bermuda, Bahamas, Cuba, Mexico.

Habitat:—Rocky and sandy bottoms with moderate surge. Subtidal to 2 m depth.

Comments: — According to Littler & Littler (1990), the internal anatomy of U. norrisii is similar to U. flabellum , however in this study, marked differences were observed between the shape of the blade and stipe appendages. These authors also mention that U. norrisii has a longitudinal divided blade, but the specimens of U. norrisii found in the study area presented a flabellate blade, so that the characters useful to determine this species were the shape of stipe and blade appendages. Udotea norrisii is registered for the first time for the Quintana Roo and Campeche littoral.