Euglena! Green flagellates with elongate, ovoid or fusiform cells, varying in length from 20 to 500 μm, and with flagella originating within an anteri

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Jeremy Boone
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Locomotion involves helical rotation of the cell and most species exhibit euglenoid movement (rapid changes of body shape) when swimming stops.

absent). The chloroplasts are grass-green and contain chlorophylls a and b, β- carotene and xanthophylls.

1 Euglena! Green flagellates with elongate, ovoid or fusiform cells, varying in length from 20 to 500 μm, and with flagella originating within an anterior invagination of the cell. Locomotion involves helical rotation of the cell and most species exhibit euglenoid movement (rapid changes of body shape) when swimming stops. Chloroplasts vary in shape (discs, plates or ribbons), size, number per cell (from 2 to several hundred) and pyrenoid type (naked, sheathed, projecting, immersed or absent). The chloroplasts are grass-green and contain chlorophylls a and b, β- carotene and xanthophylls. All species are photoauxotrophic, some facultatively heterotrophic. The reserve carbohydrate is paramylon. All species have an extraplastidial, β-carotene-containing, orange-red eyespot that curves around the reservoir on the base of the flagellum. All species are strongly phototactic. Pellicle consists of flexible, elastic, interlocking, proteinaceous strips that spiral along the cell. Reproduction occurs by longitudinal fission.!

cells irregular or triradiate cross-sections. Many species with a long posterior spine, shaped like flattened spinning tops; some species twisted into flat corkscrews.

2 Phacus! Green flagellates with rigid, compressed cells, most species being very flat and leaf-shaped, often with ridges, folds or grooves running helically or longitudinally, giving the cells irregular or triradiate cross-sections. Many species with a long posterior spine, shaped like flattened spinning tops; some species twisted into flat corkscrews. Flagella, eyespot and flagellar swelling as in Euglena. Chloroplasts usually small, discoid and numerous, usually without pyrenoids; a few species (e.g. P. splendens) have large flat chloroplasts with pyrenoids; paramylon typically deposited as a few large granules (often rings) together with many small ones.!!!

Peridinium! Although most dinoflagellates are marine, Peridinium may live in both freshwater and marine environments.

starch grains alongside the chloroplasts. At the light microscopy level Peridinium is recognized by its armor and flagellar position.

The two flagellae emerge through a lateral pore, one flagellum extends as a cingulum in the girdle surrounding the organism.

3 Peridinium! Although most dinoflagellates are marine, Peridinium may live in both freshwater and marine environments. The organism contains many small chloroplasts, carotenoids (responsible for the reddish-brown color) and usually small drops of oil and starch grains alongside the chloroplasts. At the light microscopy level Peridinium is recognized by its armor and flagellar position. The armor, composed of cellulosic plates, may bear various types of ornamentation. The two flagellae emerge through a lateral pore, one flagellum extends as a cingulum in the girdle surrounding the organism. The shorter flagellum, extends in the sulcus. Though most dinoflagellates lack the light sensitive stigma, Peridinium is an exception and possesses a plastid bound eyespot near the location of the flagellar emergence.!

Ceratium! Ceratium species are easily identifiable because of their unique shape. They are covered with an armor-like cell wall, made out of polysaccharide.

The flagella each have different movements and shapes. The transverse flagellum beats in a spiral motion, while the longitudinal flagellum pulses in waves.

4 Ceratium! Ceratium species are easily identifiable because of their unique shape. They are covered with an armor-like cell wall, made out of polysaccharide. The most distinguishing characteristic are the arms (also known as horns), the shape and size of which vary from species to species. Ceratium have two flagella. These wind around the cell body. The flagella each have different movements and shapes. The transverse flagellum beats in a spiral motion, while the longitudinal flagellum pulses in waves. Most Ceratium species also contain chloroplasts. Certain species are bioluminescent. Under adverse conditions, Ceratium are able to encyst themselves as a form of protection. Ceratium are mixotrophs, obtaining food both through photosyntheis and phagocytosis. Asexual reproduction is most common in Ceratium. However, sexual reproduction is also possible, usually taking place under adverse conditions.!

Amphidinium! Small to large (<10-100 µm) unarmored, free-living, predominantly motile, sometimes enclosed in a hyaline cyst.

The epicone is small, the hypocone large, as the cingulum is located in the anterior part of the cell. The cingulum is circular or a little displaced.

Amphiesma are delicate or rigid, smooth or with striae on hypocone or also epicone. Number of striae may differ on epicone and hypocone. Chloroplasts are present or absent.

5 Amphidinium! Small to large (< µm) unarmored, free-living, predominantly motile, sometimes enclosed in a hyaline cyst. Amphidinium are globular to fusiform, laterally or dorsoventrally compressed. The epicone is small, the hypocone large, as the cingulum is located in the anterior part of the cell. The cingulum is circular or a little displaced. The sulcus extends from cingulum to antapex, in some species to apex. Typical dinokaryon located in the hypocone. Amphiesma are delicate or rigid, smooth or with striae on hypocone or also epicone. Number of striae may differ on epicone and hypocone. Chloroplasts are present or absent. Nutrition is phototroph, phagotroph (either by ingestion of whole particles or by myzocytosis). Chloroplasts of some species may be derived from endosymbionts. Cytoplasm may be of various colors, dense granules may be present. Some species form temporary cysts. Cosmopolitan, marine, brackish or freshwater, planktonic or sand-dwelling. Some species produce unusual sterols and others toxins.!

girdle view). Valves variable in outline, usually linear-lanceolate to lanceolate, with variously shaped apices.

6 Navicula! Cells solitary, usually seen in valve view and often actively motile when live. Live cells with two plate-like chloroplasts lying along each side of girdle, each with a single rod-shaped pyrenoid along their length (only visible in girdle view). Valves variable in outline, usually linear-lanceolate to lanceolate, with variously shaped apices. Raphe central, fissures usually hooked over valve apices, slightly expanded at centre. Stria path variable, striae usually cross-lineate, i.e. containing linear pores at right angles to the direction of the stria. Girdle usually narrow, comprised of a few plain bands.!

Thalassiosira! Cells appear to be round in valve view; with a flat or undulating face.

cell divisions lead to a decrease in cell size because each daughter cell inherits one of the two

Consequently, each division cycle decreases the average size of diatom cells.

7 Thalassiosira! Cells appear to be round in valve view; with a flat or undulating face. They join into chains through chitinous threads which are extruded from strutted processes. Chloroplasts are numerous. Auxospores are frequent and involved in reestablishing the normal size in diatoms because mitotic cell divisions lead to a decrease in cell size because each daughter cell inherits one of the two valves that make up the frustule (a silica cell wall), and grows a smaller valve within it. Consequently, each division cycle decreases the average size of diatom cells. When its size becomes too small, a dividing diatom cell produces an auxospore to expand its cell size back to that which is normal for vegetative cells Cells are round and inflated between remains of parents frustules.!

8 Diatom Cell Division! Left: Schematic structure of the diatom cell (center) and diatom cell cycle. Diatom cells are shown in cross section. The gray area represents the protoplast, the green line depicts the plasma membrane. For simplicity, intracellular organelles are not shown.!! Right: Cells arranged in the circle show different stages of the cell cycle: (1) Shortly before cell division the cell wall contains the maximum number of girdle bands; (2) immediately after cytokinesis new biosilica (red) is formed in each sibling cell inside a valve silica deposition vesicle (SDV, yellow); (3) expansion of the valve SDVs as more and more silica is deposited; (4) at the final stage of valve SDV development, each SDV contains a fully developed valve; (5) the newly formed valves are deposited in the cleavage furrow on the surface of each protoplast by SDV exocytosis; (6) the sibling cells have separated; (7+8) expansion of the protoplast in interphase requires the synthesis of new silica (red ) inside girdle band SDVs ( yellow); each girdle band is synthesized in a separate SDV, and after SDV exocytosis is added to the newly formed valve (hypovalve); (9) after synthesis of the final hypovalve girdle band (pleural band) cell expansion stops, and DNA replication is initiated.!

9 Isochrysis! Isochrysis is a small golden/brown flagellate that is very commonly used in the aquaculture industry. It is high in DHA and often used to enrich zooplankton such as rotifers or Artemia. Isochrysis is a primary algae used in shellfish hatcheries and used in some shrimp hatcheries.!

astaxanthin, zeaxanthin and canthaxanthin), though it lacks chlorophyll b and

10 Nannochloropsis! Nannochloropsis is able to build up a high concentration of a range of pigments (i.e. astaxanthin, zeaxanthin and canthaxanthin), though it lacks chlorophyll b and c. It is mainly used as an energy-rich food source for fish larvae and rotifers. Recently, Nannochloropsis has also been investigated in terms of its potential as source for biofuels due to its high oil content (28.7% of dry weight), mainly unsaturated fatty acids and a significant percentage of palmitic acid. It also contains enough unsaturated fatty acid linolenic acid and polyunsaturated acid (>4 double bonds) for a quality biofuel.!

The Phytoplankton! Phytoplankton - Euglenophytes!

The Phytoplankton! Phytoplankton - Euglenophytes! 9/29/14 The Phytoplankton Phytoplankton - Euglenophytes - abundant, nutrient-rich fw, some marine = DOM facilitates abundance - auxotrophic = require vitamin B1/B12 (unable to synthesize these vitamins)