FIRST RECORD OF PYRODINIUM BAHAMENSE (DINOFLAGELLATA) IN BRACKISH WATERS OF THE MEXICAN CARIBBEAN COAST

Resumen

The analysis of water samples for cell counts (Utermá¶hl technique) and from 60 µm mesh plankton net, obtained in October 1996 from the brackish waters of the northern section of the Sian Ka'an Biosphere Reserve (20°06'3.6" -19°47'15.6" N and 87°28'55.3" - 87°29'11.8" W), in Quintana Roo, Mexico showed the existence of an important bloom of the dinoflagellate Pyrodinium bahamense Plate (Balech, 1985, Rev. Paleobot. Palynol. 45: 17-34, pl. 1-III) (Fig. 2). Higher densities (1500 cells/ ml-1 ) were found in mesohaline conditions (12-13%), corresponding toan area localized between a zone of considerable mangrove development, and the coastal underground drainage. Observed water coloration was red diluted on shallow carstic bottoms (depth from 0.9 to 1.8 m), covering a surface of 6 km2.