NOTES ON THE MARINE ALGAE OF THE INTERNATIONAL BIOSPHERE RESERVE SEAFLOWER, CARIBBEAN COLOMBIA VI: NEW RECORDS OF BROWN ALGAE (PHAEOPHYCEAE)

Notas sobre las algas marinas de la Reserva Internacional de Biosfera Seaflower, Caribe colombiano VI: nuevos registros de algas pardas (Phaeophyceae)

Benthic marine algae of the Archipelago of San Andres, Old Providence and Sainte Cataline, Colombia, have been poorly documented to date, primarily due to a paucity of floristic studies in the area. In 2003, Díaz-Pulido and Díaz-Ruiz listed a total of 201 species of marine algae, well below the number of species of other regions of Colombia. Recent works on the marine flora of the Archipelago (Albis-Salas and Gavio 2011; Ortiz and Gavio 2012; Gavio et al., 2013; Reyes-Gómez et al., 2013; Rincón-Díaz et al., 2014; Albis-Salas and Gavio, 2015; Gavio and Mancera-Pineda, 2015; Gavio et al., 2015; Barrera et al., 2016) have reported a diversity never registered before, increasing the number of seaweeds for the Archipelago to 298 taxa. During a collecting trip to Providencia and Santa Catalina Islands in 2009, we observed two species of brown algae, which have not been reported for the Archipelago before: Bachelotia antillarum (Grunow) Gerloff 1959 and Dictyota humifusa Hörnig, Schnetter et Coppejans 1992.

The species Bachelotia antillarum (Family Bachelotiaceae) (Fig. 1) has a filamentous thallus, dark brown. Uniseriate filaments are epiphytic on larger algae, attached by a prostrate filament (Fig. 1A). Vegetative cells are rectangular, longer than wide, 40-45 μm diam and 100-110 μm long. Meristematic cells are darker in color and shorter than somatic cells (Fig. 1B). Branching is scarse and distributed along the filament (Figs. 1C-1D). Chloroplasts are star-shaped, in pairs (Fig. 1E). Sporangia are unilocular, intercalary in the vegetative filament inside meristematic region of the thallus, 50 um diam and 20-25 μm long (Fig. 1F). The specimen was observed entangled with Ulva flexuosa Wulfen in Santa Catalina Island, intertidal on the beach before Morgan's Head.

Bachelotia antillarum was collected nearshore among mangrove tree roots, and formed a green-brownish patch among the roots. According to Díez et al. (2009) and Figueroa and Korbee (2010) algae with simple morphology are common in polluted places, and B. antillarum is a species that can be observed in extremely degraded systems. We consider that this is not the case for Santa Catalina Island, but it would be interesting to monitor the water quality of the area as well as any change in the algal community.

Dictyota humifusa (Family Dictyotaceae) (Fig. 2) has a flattened, band-shaped thallus, with a prostrate habit, light green in color, and blue iridescence under water (Fig. 2A). Branching is irregular to dichotomous (Fig. 2B). Blades are 85-95 μm thick. Medulla is unistratified, composed of rectangular to rounded cells, 60-65 μm diam and 100-110 μm long. Cortical cells rectangular, 15-25 μm long and 1012,5 μm diam (Figs. 2C-2D). This specimen was observed in Providencia Island, at Bajo San Felipe, at depths of 8-13 m.

Many species of Dictyota produce terpens that inhibit herbivory (Schmitt et al., 1998; Pereira et al., 2000). Stirk et al. (2007) showed that the species D. humifusa has secondary metabolites, which have antibacterial and antimycotic properties. In the study, D. humifusa was the only species to be able to hinder Escherichia coli growth. Furthermore, its extracts have inhibitory activity for Acetylcholinesterase (AChE), an enzyme which interferes with Acetylcholine, neurotransmitter involved in neurological disorders. Incrementing concentrations of Acetylcholine through inhibition ofAChE, is considered the most efficient treatment against Alzheimer disease. For this reason, D. humifusa may be of interest for pharmaceutical bioprospection (Stirk et al., 2007).

Figure 1

Figure 2

We wish to thank the divers of Felipe's diving, in Providencia, Juan Felipe Ortiz and Hernan Velasquez for field assistance. This project was funded by Universidad Nacional de Colombia, Sede Caribe, through the projects # 20101003400, # 20501003060 and # 20101004460.

The authors declare that they have no conflict of interest.

Associate Editor:: John Charles Donato Rondón.

Citation/Citar este artículo como:: Reyes-Gómez VP, Gavio B. Notes on the marine algae of the International Biosphere Reserve Seaflower, Caribbean Colombia VI: New records of brown algae (Phaeophyceae). Acta biol. Colomb. 2017;22(2):238-241. DOI: http://dx.doi.org/10.15446/abc.v22n2.60363