Prorocentrum panamensis Grzebyk et al., 1998
Species Overview:
Prorocentrum panamensis is an armoured, marine, benthic dinoflagellate species. This species is associated with turf algae from coral reefs in tropical North Pacific waters.
Taxonomic Description:
Prorocentrum panamensis is a bivalvate species often observed in valve view. Cells are broadly heart-shaped with a rounded posterior; valves are asymmetrical (Figs. 1-3). Cells range in size from 46-52 µm in length, and 43-46 µm in width. The intercalary band is transversely striated (Fig. 6) (Grzebyk et al., 1998).
Deep and large areolae (0.7-0.9 µm in diameter) cover the valve surface; the cell center is devoid of any areolae or pores (Figs. 1-3). Marginal areolae contain small pores (Fig. 4). On the right valve, adjacent to the intercalary band, is a large sieve-like depression (1.4-2.4 µm in length), the role of which is unknown (Figs. 1,4-6). This deep and ovoid depression is perforated with small pores (Fig. 5) (Grzebyk et al., 1998).
The periflagellar area is located anteriorly off-center in a shallow raised depression. It is set between the two valves, though slightly more into the right, and is surrounded by a thickened apical ridge (Figs. 1,7). The periflagellar area is nearly ovoid (13-16 µm long) and unornamented (Figs. 1,7). Two periflagellar pores are present: a smaller ovoid flagellar pore, and a larger oblong auxiliary pore (Fig. 7) (Grzebyk et al., 1998).
Morphology and Structure:
Prorocentrum panamensis is a photosynthetic species containing two golden-brown chloroplasts. Both chloroplasts contain a central pyrenoid. The large nucleus is U-shaped (Grzebyk et al., 1998).
Reproduction:
P. panamensis reproduces asexually by binary fission (Grzebyk et al., 1998).
Species Comparison:
P. panamensis is distinguished from other Prorocentrum species by several morphological characteristics: asymmetrical heart-shaped valves; unornamented periflagellar area, and presence of an oblong sieve-like depression on the right valve (Grzebyk et al., 1998). This species roughly resembles P. caribbeanum with the heart-shaped valves; however, P. caribbeanum cells are smaller and have a pointed posterior (Faust, 1993a).