Udotea abbottiorum D.S. Littler & M.M. Littler 1990:10

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 : 190

Udotea abbottiorum D.S. Littler & M.M. Littler 1990:10

Type Locality:— USA, Content Keys, Monroe County, Florida.

Morphology: — Thalli to 10 cm tall, anchored on substrata by a small bulbous mass of entangled rhizoidal siphons. Stipe cylindrical lightly calcified in lower half (4–11 mm long, 2–4 mm in diameter), the upper half flattened (6–16 mm long, 4–15 mm in diameter), forming an evident transition between the stipe and blade. Blade fan-shaped, green, longer (2–9 cm) than wider (1–9 cm), lower margin obtuse o truncate, multistratose, ecorticate (no lateral appendages), lightly calcified, and zonate ( Figs. 7, 8, 9 ).

Anatomy:—Blade siphons without lateral appendages, dichotomously branched, 45–55 μm in diameter, distance between each dichotomy ranges from 700 to 2300 μm, supradichotomic constrictions 12–24 μm length, 23–27 μm in diameter ( Fig. 10 ). Stipe siphons adjacent to lateral appendages 37–58 μm in diameter, appendages peduncle 160–500 μm length, 20–65 μm in diameter, sometimes constriction at the base. Appendages dichotomously branched 2–4 times, with swollen tips ( Fig. 11 ).

Reproduction: — Vegetative

Material examined: — MEXICO. Quintana Roo, Pulticub, 14 April 2015, J. A. Acosta Calderón, L. E. Mateo Cid, A. C. Mendoza González, ENCB 23086. MEXICO. Quintana Roo, Uvero, 13 April 2015, J. A. Acosta Calderón, L. E. Mateo Cid, A. C. Mendoza González, ENCB 23087. MEXICO. Quintana Roo, Punta Mahahual, 13 April 2015, J. A. Acosta Calderón, L. E. Mateo Cid, A. C. Mendoza González, ENCB 23090. MEXICO. Quintana Roo, Santa Rosa, 12 April 2015, J. A. Acosta Calderón, L. E. Mateo Cid, A. C. Mendoza González, ENCB 23091. MEXICO. Quintana Roo. Rio Indio, 19 December 2014, J. A. Acosta Calderón, L. E. Mateo Cid, A. C. Mendoza González, ENCB 23085. MEXICO. Campeche, Playa Villamar, 25 January 2016, J. A. Acosta Calderón, L. E. Mateo Cid, A. C. Mendoza González, ENCB 23089. MEXICO. Campeche, Lerma, 23 January 2016, J. A. Acosta Calderón, L. E. Mateo Cid, A. C. Mendoza González, ENCB 23088. Campeche, Carretera a Campeche km 732, 9-05-1966, A. Vargas, ENCB 16773.

Geographic distribution: — Florida, Bermuda, Belize, Panama, Puerto Rico, Colombia, Brazil, Mexico.

Habitat: — Sandy bottom with seagrass meadows and rock shelf with soft waves. Subtidal to 2 m deep.

Comments:—The shape of the stipe appendages and the presence of a cylindrical section shorter than the flattened portion of the stipe agrees with those described by Littler & Littler (1990). However, the diameters of stipe and blade siphons are less than those recorded in specimens from Florida, USA ( Littler & Littler 1990), and Puerto Morelos, Quintana Roo, Mexico ( Collado-Vides et al. 2009). In the Yucatan peninsula, this species has been registered only for Puerto Morelos ( Collado-Vides et al. 2009), so in this paper the distribution of U. abbottiorum is extended to the Quintana Roo coast and is recorded for the first time for the Campeche shoreline.

Figures

FIGURES 7–11. U. abbottiorum. 7–9) external morphology, 10) blade siphon and detail of the supradichotomic constriction, 11) lateral appendages of the stipe. FIGURES 12–15. U. caribaea. 12–13) external morphology, 14) blade siphon showing the distance between dichotomies, 15) lateral appendages of the stipe.