Prorocentrum caribbaeum Faust, 1993a
Species Overview:
Prorocentrum caribbaeum is an armoured, marine, benthic dinoflagellate species. This species is associated with floating detritus and sediment in tropical embayments of the Caribbean Sea.
Taxonomic Description:
P. caribbaeum is a bivalvate species often observed in valve view. Cells are heart-shaped, broad and rounded anteriorly, pointed posteriorly, and are broadest in the anterior end (Figs. 1,2). Cells are 40-45 µm long and 30-35 µm wide (Faust, 1993a).
The thecal valves are covered with two different sized pores: large trichocyst pores (0.3 µm in diameter) and small surface pores (0.1 µm in diameter) (Figs. 4,6-8). Trichocyst pores are numerous (145-203 per valve) and radiate perpendicularly from the valve margins (Figs. 1,2). These pores are round furrowed depressions with smooth edges, and even in size (Figs. 6,8). Cells in natural samples are often observed with ejected trichocysts (Fig. 8). The small pores are round with smooth edges, unevenly distributed (Figs. 4, 6-8). The cell center is devoid of pores. The intercalary band is transversely striated and sinuous (Fig. 9) (Faust, 1993a).
The periflagellar area is a broad V-shaped depression located apically off-center on the right valve (Figs. 1,3-5), surrounded by a thickened apical ridge (raised margin) (Fig. 4). This region houses a prominent curved winged periflagellar collar (2 X 6 µm) adjacent to the auxiliary pore; opposite this and adjacent to the flagellar pore is a smaller protuberant periflagellar plate (1 X 2 µm) (Figs. 1,3-5). Under LM, the curved periflagellar collar may appear as a short winged spine (Faust, 1993a).
Morphology and Structure:
Prorocentrum caribbaeum is a photosynthetic species containing golden chloroplasts. No pyrenoid present. The nucleus is large, kidney-shaped, and posteriorly located (Faust, 1993a).
Reproduction:
Prorocentrum caribbaeum cells reproduce asexually by binary fission.
Species Comparison:
The heart-shaped Prorocentrum caribbaeum resembles P. mexicanum and P. micans in general cell shape; however, P. caribbaeum is broader and heart-shaped, and broadest in the anterior region. P. mexicanum is smaller and oblong with straight sides and a rounded posterior, while P. micans is tear-drop shaped and broadest in the mid-section. P. caribbaeum and P. micans are in the same size range (Dodge, 1975, Dodge, 1985, Faust, 1993a).
Pore morphology is also similar in these three species display radially arranged trichocyst pores and smaller valve pores. Significant differences lie, however, in the number of trichocyst pores: P. caribbaeum has the greatest number of pores (145-203 per valve); P. mexicanum has the fewest number of pores (100 per valve); and P. micans has a variable number of trichocyst pores. Ejected trichocysts are often observed in cells of P. mexicanum and P. caribbaeum (Loeblich et al., 1979b, Dodge, 1985, Faust, 1990b, Faust, 1993a, Fukuyo et al., 1990).
The periflagellar area and periflagellar platelet architecture of P. caribbaeum is similar to that of P. mexicanum (Carlson, 1984, Faust, 1993a).
The intercalary band of P. caribbaeum is transversely striated. This is similar to P. emarginatum, P. mexicanum and P. playfairi (Croome and Tyler, 1987, Faust, 1990b, Faust, 1993a).