Prorocentrum sabulosum Faust, 1994
Species Overview:
Prorocentrum sabulosum is an armoured, marine, sand-dwelling, benthic dinoflagellate species. This species is associated with colored sand and coral rubble in tropical embayments of the Caribbean Sea.
Taxonomic Description:
Prorocentrum sabulosum is a bivalvate species often observed in valve view. Cells are oval (Figs. 1,2) and range in size from 48-50 µm in length and 41-48 µm in width. The valve surface is heavily areolated (Figs. 1-6). The large areolae (1.0-1.6 µm in diameter) are round to oval; approximately 332-450 areolae are present on each valve (Figs. 1-6). Trichocyst pore openings appear as oblong depressions within the areolae (Figs. 5,6). The intercalary band is smooth and void of striation (Figs. 1-3). Marginal areolae give a flared ridge appearance (Figs. 7,8) (Faust, 1994).
The periflagellar area is a small narrow V-shaped triangle located apically on the right valve; both left and right valves are excavated (Figs. 1,3-5). Two periflagellar pores are present: a large flagellar pore and a smaller auxiliary pore (Figs. 3-5); the auxiliary pore is surrounded by a narrow periflagellar collar (Figs. 3-5). Adjacent to the flagellar pore is a large accessory pore; adjacent to the auxiliary pore are three smaller accessory pores (Figs. 3-5). The left valve margin exhibits a raised, curved, flattened apical collar that borders the periflagellar area (Figs. 3-5) (Faust, 1994).
Morphology and Structure:
Prorocentrum sabulosum is a photosynthetic species containing golden brown chloroplasts. The nucleus is situated posteriorly (Fig. 8) (Faust, 1994).
Reproduction:
Prorocentrum sabulosum reproduces asexually by binary fission.
Species Comparison:
The large areolae of P. sabulosum are distinct from similar known benthic Prorocentrum species: P. hoffmannianum has approximately 670 areolae per valve (1.1 µm in diameter) (Faust, 1990b); P. belizeanum has about 950 areolae per valve (0.7 µm in diameter) (Faust, 1993a); and P. ruetzlerianum has about 550 pentagonal-shaped areolae per valve (1.0 µm in diameter) (Faust, 1990b).
The architecture of the periflagellar area of P. sabulosum is distinct from P. belizeanum (Faust, 1993a), P. lima (Faust, 1991), and P. concavum (Fukuyo, 1981). The periflagellar area of the latter three species has eight platelets, whereas P. sabulosum appears more complex (Faust, 1994). P. reticulatum (Faust, 1997), P. sabulosum (Faust, 1994), P. belizeanum (Faust, 1993a) and P. hoffmannianum (Faust, 1990b) share a distinct feature in the periflagellar area: three small accessory pores adjacent to a periflagellar pore (Faust, 1997).
The anterior region of the left valve in both P. sabulosum and P. reticulatum exhibits a curved and flattened apical collar that borders the periflagellar area (Faust, 1997).
The intercalary band of P. sabulosum is smooth and void of striation. The intercalary band is also smooth in P. hoffmannianum (Faust, 1990b), but horizontally striated in P. belizeanum (Faust, 1993a).