Prorocentrum belizeanum Faust, 1993a
Species Overview:
Prorocentrum belizeanum 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:
Prorocentrum belizeanum is a bivalvate species often observed in valve view. Cells are round to slightly oval (Figs. 1,2). Cells measure between 55-60 µm in length and 50-55 µm in width. Valves are concave in the center (Figs. 3,4) (Faust, 1993a).
The thecal surface is heavily areolated; approximately 853-1024 areola are present on each valve (Figs. 1-4). The areolae are round to oval (0.66-0.83 µm in diameter) (Figs. 1-5). Some bear trichocyst pores at their base (from inside the valve they appear as round depressions) (Figs. 5,6). Ejected trichocysts are often observed (Fig. 5). The intercalary band is smooth (Fig. 7). Marginal areolae give the appearance of a transversely striated intercalary band (Figs. 11,12) (Faust, 1993a).
The periflagellar area is a V-shaped triangle located apically on the right valve (Figs. 1,4,8). Both the left and right valves are excavated (Figs. 1,4). The two periflagellar pores, flagellar and auxiliary pores, are equal in size. The auxiliary pore is surrounded by a flared periflagellar collar (Fig. 8). Accessory pores are also present. The left valve anterior margin bears a large rounded and flared curved apical collar that borders the periflagellar area (Figs. 1-4,8,11,12). In lateral view, the curved apical collar resembles a rounded lip (Fig. 3) (Faust, 1993a).
Morphology and Structure:
Prorocentrum belizeanum is a photosynthetic species with a centrally located pyrenoid. A large kidney-shaped nucleus is situated posteriorly (Fig. 12) (Faust, 1993a).
Reproduction:
Prorocentrum belizeanum reproduce asexually by binary fission.
Species Comparison:
Only a few round or near-round Prorocentrum species are known: P. belizeanum is larger then P. hoffmannianum (45-55 µm long and 40-45 µm wide) (Faust, 1990b) and larger than P. compressum (36 µm in diameter) (Matzenauer, 1933, Böhm, 1936, Schiller, 1937, Tafall, 1942, Dodge, 1975).
The areolae of P. belizeanum are distinct from similar known benthic Prorocentrum species (Faust, 1993a): P. hoffmannianum has approximately 670 areola per valve (1.0-1.15 µm in diameter), and P. ruetzlerianum has about 550 pentagonal-shaped areola per valve (1.0 µm in diameter) (Faust, 1990b).
The architecture of the periflagellar area of P. belizeanum is similar to P. lima (Taylor, 1980) and the planktonic species P. playfairi (Croome and Tyler, 1987). P. hoffmannianum (Faust, 1990b), however, has a more complex platelet configuration (Faust, 1993a). The periflagellar area of P. belizeanum lacks an apical spine (Faust, 1993a), which is similar to P. hoffmannianum (Faust, 1990b) and P. lima (Faust, 1991), but different from P. compressum, which has two apical spines (Tafall, 1942, Dodge, 1975). 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 flared curved apical collar (or 'raised anterior ridge') on the left anterior margin of P. belizeanum is similar to the curved apical collar of P. hoffmannianum. However, P. belizeanum has a rounder and more prominent collar than P. hoffmannianum (Faust, 1990b, Faust, 1993a, Steidinger and Tangen, 1996).