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A new marine heterotrophic dinoflagellate species, Protoperidinium belizeanum sp. nov., from a coral reef-mangrove pond was identified from scanning electron micrographs. Recognition of this new species was based on unique features of the thecal morphology, which included cell size and shape, presence of short and wide postcingular plates, sulcal architecture, antapical spines, and intricate thecal plate patterns of ridged hexagonal depressions. The thecal plate formula is as follows: Po, X, 4′, 3a, 7″, 4C (3+t), 6S, 5‴, 2″″. Species association of P. be-lizeanum sp. nov. within the genus Protoperidinium , its habitat, and associated dinoflagellates species are discussed. [ABSTRACT FROM AUTHOR]

A new marine heterotrophic dinoflagellate species, Protoperidinium belizeanum sp. nov., from a coral reef-mangrove pond was identified from scanning electron micrographs. Recognition of this new species was based on unique features of the thecal morphology, which included cell size and shape, presence of short and wide postcingular plates, sulcal architecture, antapical spines, and intricate thecal plate patterns of ridged hexagonal depressions. The thecal plate formula is as follows: Po, X, 4′, 3a, 7″, 4C (3+t), 6S, 5‴, 2″″. Species association of P. be-lizeanum sp. nov. within the genus Protoperidinium , its habitat, and associated dinoflagellates species are discussed. [ABSTRACT FROM AUTHOR]

Three new bwnthic, photosynthetic dinoflagellate species, Prorocentrum norrisianum, from floating detritus and coral rubble of Central America are described from scaning electron micrographs. Species were identified based on shape size surface micromorphology ,thecal plate ornamentation, and architecture of the perflagellar area and intercalary band. Cells of P. norrisianum are avate with a cell size of 20-25 μm long and 13-16 μm wide. The theca is delicate its surface smooth, pores species specific with 95-105 pores per valve, Pores are round with a diameter of about 0.1 μm The periflagellar area is V-shaped located on the right valve in a shallow depression. It has no ornamentation.The flagellar and auxiliary pores are unequal in size. The interacalry band is smooth. Proroentrum tropicalis cells are avoid, 50-55 μm long and 40-45 μm wide in valve view with maximum width behind the middle region, narrow at the right valve, is a V-shaped periflagellar area, situated in the right valve, is a V-shaped wide triangle with a deeply indented depression; the left valve exhibits a flat ridge. The periflagellar area is unornamented and the flagellar and auxiliary pores are unequal is size. The valve surface is rugose with evenly distributed galve poroids. Each poroid appears to have a small dome in the center. The intercalary band is rimlike around the cell margin, granulated and horizontally striated. Prorocentrum reticultum cells are oblong in valve view cells are 55-60 μm long and 40-45 μm wide .Thermal surface is reticulated it is composed of a labyrinth of ridges with alternating depressions that wavy in size and shape. Each depression has a narrow ablong kidney shaped opening about 0.6 μm long.The periflagellar area is a deep V-shaped trangle. The right valve of P reticulam is excavated and contains a large flagellar pore and a smaller auxi,iiary pore surrounded by a barrow optical collar.The left valve margin edhinits a curved flat ridge.The intercalary band is smooth. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive examination of the taxonomy of the genus Ostreopsis Schmidt. The morphology of six species of marine dinoflagellates, Ostreopsis siamensis Schmidt 1902, Ostreopsis lenticularies Fukuyo 1981, Osteropsis ovata Fukuyo 1981, Ostreopsis heptagona Norris, Bomber, et Balech 1985, Ostreopsis mascarenensis Quod 1994, from three geographical regions (Japan, Southwest Indian Ocean, and the Caribbean) and three marine habitats (sand, water column, and macroalgal surfaces) are described from scanning electron micrographs. Differences in the following morphological characteristics differentiated the species: cell shape and size, and ornamentation of the epitheca, cingulum, and hypotheca. The thecal plate formula of six Ostreopsis species is P[suba], 3',7", 6C, 6S?, V[subP], R[subP] 5"', 1P, 2"", with differences in thecal plate size and shape. The cingulum in ventral view has two prominent structures: a ventral plate (V[subp]) with a ventral pore (V[aubo]) and a ridged plate (R[subp]) that distinguishes Ostreopsis species from any other dinoflagellate taxa. This paper also includes ecological and toxicity information regarding the six Ostreopsis species. [ABSTRACT FROM AUTHOR]

The thecal surface morphology of Scrippsiella subsala (Ostenfeld) Steidinger et Balech was examined using the scanning electron microscope. This species is distinguished by a number of morphological characteristics. Aplcal plate 1' is wide, asymmetric, and pentagonal, and it ends at the anterior margin of the cingulum. Intercalary plates 2a and 3a are separated by apical plate 3'. The apical pore complex includes a large P[SUBa] plate with a raised dome at the center and a deep canal plate with thickened margin at plates 2', 3', and 4'. The intercalary bands are wide and deeply striated. The cingulum is deep, formed by six cingular plates; its surface is transversely striated and aligned with a row of minute pores. The cingular list continues around postcingular plate 1[SUPm] to form a sulcal list. The sulcal list is a flexible ribbon with a rounded tip that protrudes posterioly, partially covering the sulcal plates. The hypotheca is lobed, and the antapical plates are irregularly shaped and wide in antapical view: The thecal surface is vermiculate to reticulate. A comparison in morphology and ecology is presented between S. subsalsa and other known Scrippsiella species. [ABSTRACT FROM AUTHOR]

Three new benthic, sand-dwelling dinoflagellate species, Prorocentrum sabulosum, prorocentrum scuptile, and prorocentrum arenarium, from coral rubble are described from scanning electron micrographs. Species were identified based on shape, size, surface micromorphology, ornamentation of thecal plates, and architecture of the periflagellar area and intercalary band. Cells of P. sabulosum are oval with a cell size of 48-50 μm long and 41-48 μm wide. The areolae are round to oval and numerous (332-450 per valve) and range from 1 to 1.6 μm in size. The periflagellar area of P. sabulosum bears a wide V-shaped depression with a flat ridge and lacks ornamentation; it accommodates six pores: one large flagellar pore, an adjacent smaller auxiliary pore, and four pores of unknown function. The flagellar and auxiliary pores are surrounded by a narrow apical collar. The intercalary band of P. sabulosum is smooth. Prorocentrum sculptile cells are broadly oval, 32-37 μm long, and 30-32 μm wide in valve view with a deep-sculptured apical area. The valves are smooth and are marked with shallow depressions (856-975) per valve). Some of these depressions have a small round opening (0.13 μm in diameter). The periflagellar area is V0shaped with a deeply indented depression; it accommodates the two flagella and a thin angled apical plate. The intercalary band is smooth. Prorocentrum arenarium cells are nearly round in valve view 30-32 μm in diameter. Thecal surface is smooth with scattered kidney-shaped valve poroids (65-73 per valve) and marginal poroids (50-57 per valve). Length and width of poroids are 0.62 μm and 0.36 μm, respectively. The periflagellar area is an unornamented, broad triangle into which a large flagellar pore and a smaller auxiliary pore are fitted. Both flagella, longitudinal and transverse, protrude from the flagellar pore. The intercalary band is smooth. The presence of a peduncle-like structure (2-3 μm long) in P. arenarium was observed situated in the flagellar pore. [ABSTRACT FROM AUTHOR]

This study indicates that bilaterally flattened, armored, benthic dinoflagellates are more diverse in morphology than previously known. A new species, Plagiodinium belizeanum Faust et Balech gen. et sp. nov., is described in floating detritus from Twin Cays, Belize, mangrove habitats. Plagiodinium belizeanum cells are small, with dimensions of 26.5-30.5 μm in length, 20-24.5 ???m in width, and 6.5-8.5 μm in depth. Cells are ablong and bilaterally compressed with a posteriorly located, spherical nucleus, many chloroplasts, and spherical starch granules. The epitheca descends ventrally, is cap-shaped, and is composed of five plates and a very small platelet provisionally named P??? situated in the center. The epitheca is narrowly oval in opical view with a pointed truncated ventral side and a rounded dorsal side. The cingulum is composed of five plates. The hypotheca is constructed of five posteriorly elongated postcingular plates and one antapical plate. The sulcus is very short and narrow, comprised of five small plates. The thecal plate arrangement of P. belizeanum is P[SUB0] 5', O′, 5C, 1′′, 5S. No lists are present. Thecal plates have a smooth surface with small and irregularly scattered pores. The intercalary bond is smooth on the outer cell surface and broadly striated on its inner surface. We conclude that P. belizeanum represents a new, benthic, peridinioid, armored genus, Plagiodinium gen. nov. The taxonomic position of P. belizeanum sp. nov. is compared to related sand-dwelling and bilaterally flattened benthic dinoflagellates [ABSTRACT FROM AUTHOR]

Three new benthic dinoflagellate species. Prorocentrum belizeanum, Prorocentrum elegans, and Pro-rocentrum caribbaeum, from mangrove floating detritus are described from scanning electron micrographs. Species were identified based on shape, size, surface micromorphology, ornamentation of thecal plates, and architecture of the periflagellar area and intercalary band. Cells of P. belizeanum are round to slightly oval with a cell site o.[55-60 urn long and 50-55 μ wide. Areolae are round and numerous (855-1024 per valve)and range from 0.66 to 0.83 μm in site. The periflagellar area of P. belizeanum is a broad V-shaped depression; it accommodates a flagellar and an auxiliary pore and a flared, curved apical collar. The intercalary band of P. belizeahum is horizontally striated. Prorocentrum elegans is a small species 15-20 μmlong and 10-14 μm wide, with an ovate cell shape. The thecal surface is smooth. Two sites of value pores were recognized: large, round pores (20-22 per valve) arranged in a distinct pattern and smaller pores situated in an array along the intercalary band. The periflagellar area is V-shaped; it accommodates an uneven sited flagellar pore, an auxiliary pore, and an angled protuberant flagellar plate. The intercalary band is transversely striated. It is a bloom.forming species. Prorocentrum caribbaeum cells are heart-shaped with a rounded anterior end and a pointed posterior end. Cells range from 40 to 45 tun long and 30 to 35 μm wide. Thecal surface has two different-sized pores: large, round pores (145-203 per valve) arranged perpendicularly from the posterior margins, and small, round pores unevenly distributed on the thecal surface. The periflagellar area is ornate. It is V. shaped with a curved apical collar located next to the auxiliary pore; a smaller protuberant apical plate is adjacent to the flagellar pore. The intercalary band is transversely striated and sinuous. Cells are active swimmers. [ABSTRACT FROM AUTHOR]

Compares the surface morphology of the dinoflagellate Coolia monotis Meunier with the surface morphology of Ostreopsis. Similarity of the architecture of the apical pore of C. monotis to that of Ostreopsis; Location of a ventral pore in C. monotis on the right ventral margin before aplical plate 1' and precingular plate 6"; Asexual reproduction.

Two new dinoflagellate species, Prorocentrum hoffmannianum and Prorocentrum ruetzlerianum, and four known species, Prorocentrum emarginatum Fukuyo 1981, Prorocentrum mexicanum Tafall 1942, Prorocentrum concavum Fukuyo 1981, and Prorocentrum lima (Her.) Dodge 1975, from floating detritus and sediments in a subtropical mangrove island, Twin Cays, Belize, Central America are described from scanning electron micrographs. Differences in the following characters of surface micromorphology separated the species: ornamentation of thecal plates (shape, size, and number of valve pores and areolae) and the architecture of the periflagellar area and intercalary band. [ABSTRACT FROM AUTHOR]

Studies growth and pigment concentrations of the estuarine dinoflagellate, Prorocentrum mariae-lebouriae in cultures grown in white, blue and red radiation at three different irradiances. Photon flyx densities; Clorophyll concentrations.

The periplast of Cryptomonas ovata var. palustris is composed of polygonal plates which are delineated by shallow ridges. A small ejectosome is located at each corner of the plate area. The plate areas vary in size; they are smallest at the anterior and posterior ends and are largest in the middle of the cell with an average length of 0.5 μ and of width 0.1 μ. In cross section a plate area is composed of 2 distinct layers, an outer plasma membrane layer with a fine particulate appearance, and an inner layer consisting of two sheets. The sheets of the inner layer have a striated lattice pattern with a periodicity of about 20 nm. In negatively stained preparations one lattice appears to underlie another at certain angles. Protease digestion removed polygonal shaped inner layer. [ABSTRACT FROM AUTHOR]

The surface structures of the bivalvate dinoflagellate Prorocentrum mariae-lebouriae are described in detail it has an almost spheroidal shape in face view, a compressed saucer-shape in side view, with a distinct striated band at the edge of the cell. Its surface is covered with small spines in a regular pattern, with 450 nm distance between pairs. The spines are 100-120 nm wide and 200-300 nm long. There are 600-700 spines on each valve. At the anterior cell end, one of the valves has a V-shaped depression which contains a specialized structure accommodating the 2 flagellar pores. The flagellar pores are enclosed by 8 small, thick plates held together and to the valves by sutures. The flagellar pore area consists of 2 distinct structures: an apical collar possessing a curved forked plate and a larger structure composed of an unbranched plate. There are 2 flagellar canals located between the flagellar pore plates. Beneath each flagellar canal lies a row of 11 microtubules. A row of microtubules forming a microtubular cylinder is situated adjacent to the oblong flagellar canal near a sample pusule. The microtubular cylinder encircles electron dense bodies. The bases of the longitudinal and transverse flagella appear to lie at an angle to each other. The above features are illustrated with transmission and scanning electron micrographs. [ABSTRACT FROM AUTHOR]

Growth of Chroomonas sp. increased with light intensity (100, 1800, and 2700 μw/cm[sup2]) with a five-fold increase from the lowest to the highest intensity. Chlorophyll and phycocyanin content per cell were greater in cells grown at low light intensity, but the ratio of chlorophyll a and c did not vary appreciably. Cells grown at low light intensity had 30% more phycocyanin than cells grown at high intensities of light. The chloroplast of cells with the higher phycocyanin content had average intrathylakoidal widths of 300 Å, whereas those cells with the lower phycocyanin content had average intrathylakoidal withs of 200 Å. This result is compatible with hypothesis that phycocyanin is located in the intrathylakoidal space in the cryptophyte algae. Of the various energy sources tested, only glycerol was able to support limited growth under nonphoto-synthetic conditions. Under no condition was the chloroplast reduced to an etioplast or proplastid state. Starch accumulation was greatest in cells grown in continuous white light in glycerol. Eye-spots were commonest in cells grown in darkness and interrupted every 24 hr by a few seconds of white light. It was concluded that this organism is an obligate phototroph. [ABSTRACT FROM AUTHOR]