New records of green (Chlorophyta) and brown algae (Phaeophyceae) for Cabezo Reef, National Park Sistema Arrecifal Veracruzano, Gulf of Mexico

Descriptions of 13 green and 12 brown algal species from 20 genera and 15 families collected on Cabezo Reef of the National Park Sistema Arrecifal Veracruzano in the southwestern Gulf of Mexico, which are new records for the reef, are given. The species belong to the chlorophyte genera  Caulerpa, Cladophoropsis ,  Codium, Dictyosphaeria, Ernodesmis, Halimeda, Neomeris, Parvocaulis, Percursaria  and  Rhipocephalus  and the phaeophycean genera Canistrocarpus, Colpomenia, Cladosiphon, Dictyerpa, Dictyota, Ectocarpus, Padina, Rosenvingea, Sargassum  and  Sphacelaria.  The family Dictyotaceae contained the largest number of species (6). The descriptions include morphometric and biological data and are accompanied by photographs and line drawings for each species. Data on the geographic distribution in the State of Veracruz, park and the Gulf of Mexico in general are also given. Percursaria percursa  is a new record for the park, while  Dictyerpa jamaicensis, Sargassum furcatum, Caulerpa racemosa  var.  occidentalis  and  Codium isthmocladum  subsp. clavatum  are new records for the State of Veracruz. Most of the specimens of Chlorophyta were found in the vegetative stage, whereas all the brown algal species except  Dictyerpa jamaicensis  and  Sphacelaria rigidula possessed gametangia or sporangia.


INTRODUCTION
In the State of Veracruz, a total of 54 brown and 100 green algal species have been found, and in the National Park Sistema Arrecifal Veracruzano (NPSAV) in particular, 39 brown and 74 green algal species (Lehman, 1993;Dreckmann, 1998;Ortega et al., 2001;Galicia-García & Morales-García, 2007Godínez-Ortega et al., 2009). The largest number of species was encountered on Isla Enmedio, Isla Verde, Isla Sacrificios and Hornos Reef, which is proportional to the number of studies carried out at these sites, followed by La Blanquilla, Santiaguillo, La Gallega, Punta Gorda, Giote, Ingenieros and Blanca reefs. There is no published information on brown and green algae from Cabezo Reef. According to Lehman (2007), Santiaguillo is third in terms of registered brown and green algal species (28).
To contribute to our knowledge of the morphology and species of Chlorophyta and Phaeophyceae of the NPSAV occurring on Cabezo Reef and to document their records were the main purposes of the present study.

MATERIAL AND METHODS
During CEPIA boat trips within the NPSAV, specimens of green and brown algae were collected on Cabezo Reef (Fig. 1) on 11th March and 12th November 2008 and 3rd June 2010 during snorkeling at 0.5 to 1.5 m depth, manually or with a knife, and placed into a 500-ml plastic bottle or a Ziplock plastic bag filled with seawater from the sampling site. Immediately after sampling, a stock 37% formaldehyde solution was added to the samples to a final concentration of 4%. The samples were incorporated into the collection of liquid samples and the herbarium of macroalgae of the Instituto de Ciencias Marinas y Pesquerías de la Universidad Veracruzana (ICIMAP-UV). In the laboratory, morphological fea-  tures were observed and described using a stereoscopic low-magnification Carl Zeiss Stemi 2000C microscope. When necessary, cross-sections of algal thalli were made with a razor and photographed using an Olympus BX51 microscope equipped with phase-contrast objectives and an Olympus C7070 Wide Zoom 7.1-megapixel digital camera. A camera lucida was also used to make line drawings. Specimens were identified with the use of specialized literature (Taylor, 1960;Joly, 1967;Earle, 1969;Flores-Moya & Conde, 1998;Moreira & Suárez, 2002;Solé & Foldats, 2003;Boraso de Zaixso, 2004;Miranda Alves et al., 2010;. In our species descriptions, anatomical and morphological terms for macroalgal structures given by  were followed, with some exceptions. Abbreviations

RESULTS
Descriptions of 13 green and 12 brown algal species from 15 families collected on Cabezo Reef are given below. They include morphometric and biological data and are accompanied by photographs and line drawings for each species. The data on the geographic distribution in the NPSAV, the State of Veracruz and the Gulf of Mexico in general are also presented. However, the primary literature sources cited in floristic lists by Dreckmann (1998), Ortega et al. (2001) and Galicia-García & Morales-García (2007) were omitted. More recent publications (Orduña-Medrano, 2004;González-Gándara et al., 2007;Lehman, 2007;Godínez-Ortega et al., 2009) were considered. The taxa are given in the order following Fredericq et al. (2009 zuela, 1987).
GOM: Caulerpa racemosa is distributed throughout the gulf .
Examined specimens: ICIMAP-UV-AL 51, 51R, 51R2 (12 November 2008). The subsp. clavatum is a new record for the State of Veracruz. The species C. isthmocladum was reported for this area (Valenzuela, 1987;Dreckmann, 1998), and the var. isthmocladum was found on Isla Sacrificios and Hornos Reef of the NPSAV .
GOM: NE, NW and SE . References: Taylor Thallus pseudoparenchymatous, erect, 3-6 cm long, moderately calcified, solitary or in pairs, consisting of capitulum or cap (composed of narrow blades radially arranged), simple stalk and holdfast of fine siphons interlaced with sand particles. Dark green, loses color rapidly after exposure to light. Stipes cylindrical, smooth, 1-4 cm long and 2-3 mm in diam. Surface siphons compact, dichotomously branched in a single plane, with thin walls and rounded finger-like apices. Cap ovoid, 2-3 cm long; blades minute, 0.6-1 cm long. Siphons in blades are laterally fused together, 200-220 µm in proximal part and 50-100 µm in distal part, constricted at base, after the first dichotomous division. Siphons in stipes with repeatedly ramified appendages, finger-like, grouped into packages. Attaches to the substrate by a rhizoidal mass (holdfast).
Thallus unbranched, erect, minute, umbrella-shaped, 1-4 mm long, with a solitary plane or slightly concave downwards disc (cap) 1-5 mm in diam., with 21-23 rays. Deep brown green or bright green. Margins of the rays slightly sharp-pointed by 6-9 scars left by sterile hairs, arranged elliptically at base of the rays. Cylindrical calcified stalk 4 mm long and 300-600 µm wide. Gametangia in mature thallus are rays containing cysts. Cysts spherical, numerous, 50-100 µm in diam., sometimes up to 50 cysts per ray.
Note. Silva et al. (1996),  and  conclude that Dictyerpa jamaicensis represents a growth stage in the life history of Padina but cannot be assigned with certainty to any particular species.
Note. The species has been previously reported for the State of Quintana Roo (Caribbean Sea), and most likely it is in the process of expanding its range (Dreckmann, 1998).
A new record for the State of Veracruz. For this species, Ortega et al. (2001: 333) only indicate "Veracruz" without giving any details about localities.

ACKNOWLEDGMENTS
Our thanks to Captain Cipriano Anaya-Cruz for logistic support, Luz Elena Mateo-Cid and A. Catalina Mendoza-González for their hospitality in the Laboratory of Phycology at Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional in Mexico City, Horacio Pérez-España from Instituto de Ciencias Marinas y Pesquerías, Universidad Veracruzana (ICIMAP-UV) for both logistic and financial support with the boat trip in 2010. The help of Sachico Hayasaka-Ramírez (ICIMAP-UV) in obtaining necessary literature is very much appreciated. Marcia M. Gowing from the University of California at Santa Cruz, California, USA, kindly improved the writing style. The present study was a part of the project of the Dirección General de Investigaciones de la Universidad Veracruzana "Algas de la zona arrecifal Veracruzana, Golfo de México, con énfasis en las algas rojas, diatomeas y dinoflagelados" (2007)(2008)(2009) given to YBO. Financial support of "Programa de Mejoramiento del Profesorado" to the project "Patrones de distribución de la diversidad y biomasa de grupos funcionales clave para el Sistema Arrecifal Veracruzano" (2011-2012) is also appreciated.