Astasiaceae

Distigma sennii Pringsheim, 1942. Metabolic swimming euglenid, cell typically club-shaped, broader anteriorly and truncated with an apical canal-opening, the posterior end of cell tapers, cells are 40 - 62 microns long. With two flagella, unequal in length. The longer flagellum is about 0.25-0.35 cell length and the recurrent flagellum is very short (5 - 6 microns), slightly curved and directed sideways or to the posterior of the cell. The pellicle seems smooth. The reservoir is in the middle of the cell with an associated contractile vacuole. A nucleus is located centrally or slightly behind the centre of the cell. The cell contains a large number of ellipsoidal or cylindical refractile grains and when swimming the cell moves quickly and rotates.

Distigma (die-stig-ma), heterotrophic euglenid flagellate. There are two flagella which are attached to the cell in a flagellar pocket which is an invagination that leads to the front of the cell by a tube called the flagellar canal. The light disc near the front is the contractile vacuole which is located alongside the flagellar pocket which cannot be seen in this image. One flagellum is long, the other short. The cytoplasm has large amounts of paramylon granules. The cell can squirm (is metabolic). Phase contrast.

Portrait of Cyclidiopsis acus (Korschikoff, 1917), a colorless euglenoid flagellate. Similar in general morphology to Euglena acus but without plastids. Flexible but not metabolic. Swims or glides slowly. One short emergent flagellum less than one quarter body length. The pale orange stigma is visible here at the junction of the anterior apical canal and the reservoir. The contractile vacuole is posterior to the reservoir. Multiple long, needle-shaped paramylon bodies are visible in the cytoplasm. From standing freshwater. Boise, Idaho.June 2005.DIC.

Portrait of Cyclidiopsis acus (Korschikoff, 1917), a colorless euglenoid flagellate. Similar in general morphology to Euglena acus but without plastids. Flexible but not metabolic. Swims or glides slowly. One short emergent flagellum less than one quarter body length. The pale orange stigma is visible here at the junction of the anterior apical canal and the reservoir. The contractile vacuole is posterior to the reservoir. Multiple long, needle-shaped paramylon bodies are visible in the cytoplasm. From standing freshwater. Boise, Idaho.June 2005.DIC.

Distigma proteus Ehrenberg, 1838. Body highly metabolic, scarcely ever presenting the same contour, usually more or less elongate, with irregular constrictions and distensions, longer flagellum nearly equaling the body in length, the shorter one scarcely one quarter that length, endoplasm transparent, enclosing numerous dark coloured refringent corpuscles whose positions are constantly shifting from one extremely to the other in accordance with the peristaltic motions of the body, two minute, blackish, eye-like pigment-spots usually developed at the anterior extremity, tubular pharynx slender, greatly prolonged, contractile vacuole conspicuous, located close to the termination of the pharynx, nucleus ovate, subcentral. Length 44-106 microns

SEM, various cells.

Distigma proteus clavatum Playfair, 1921. Cells are 18-44 microns long and 8-12 microns wide. see Menoidium pellucidum var clavatum.

SEM of dividing cell.

Scanning electron micrographs showing two stages of contraction (metaboly).

Scanning electron micrograph of anterior end.

Euglenid without chloroplasts, highly metabolic, two flagellae, one of them trailing. More details in ZIP archive. Collection from sptagnum pond Dosenmoor near Neumuenster (Schleswig-Holstein, Germany). Images were taken using Zeiss Universal with Olympus C7070 CCD camera.

Euglenid without chloroplasts, highly metabolic, two flagellae, one of them (short one) trailing. Scale bar indicates 50 µm.  Sample from the pond Hegne Moor situated in the vicinity of Lake Constance (Bodensee, Southern Germany). Images were taken using Zeiss Universal with Olympus C7070 CCD camera.

Motion study of Distigma proteus. Scale bar indicates 50 µm.  Sample from the pond Hegne Moor situated in the vicinity of Lake Constance (Bodensee, Southern Germany). Images were taken using Zeiss Universal with Olympus C7070 CCD camera.

Astasia (a-stays-ee-a) is a colourless euglenid, probably having derived from a lineage with plastids. With one emergent flagellum (by which it can be distinguished from Distigma which is similar but has two emergent flagella. There is no mouth, although this cell is unusual in that it has inclusions - indicating that it has ingested sulphur bacteria and cyanobacteria. Flagellum with whiplash beat (loops are flicked along the length of the flagellum, and in swimming cells these tend to be directed towards the rear so that the cell swims forward following a spiral path. Phase contrast.

Astasia (a-stays-ee-a) is a colourless euglenid, probably having derived from a lineage with plastids. With one emergent flagellum (by which it can be distinguished from Distigma which is similar but has two emergent flagella. There is no mouth. Most of the refractile granules are polysaccharide storage materials. Differential interference contrast.

Astasia (a-stays-ee-a) is a colourless euglenid, probably having derived from a lineage with plastids. With one emergent flagellum (by which it can be distinguished from Distigma which is similar but has two emergent flagella. There is no mouth. Most of the refractile granules are polysaccharide storage materials. The clear area near the front of the cell is the region of the flagellar pocket (where the flagella attach to the cell) and contractile vacuole. The relatively homogeneous region in the centre of the cell is where the nucleus is located. Differential interference contrast.

Astasia curvata Klebs, 1893. Astasia cells that are spindle-shaped or cylindrical, somewhat flattened, strongly curved with tapered ends. Anterior end opened and posteriorly pointed. Cells strongly metabolic, 32-40-60 microns long, 5-8 microns broad. Flagellum about 0.5-0.66 times cell length. Many small oblong paramylon granules. Nucleus ellipsoidial, almost central.

Cyclidiopsis (sigh-clid-ee-op-sis) is a colourless heterotrophic euglenid, but is unusual in that it has an eyespot seen just below the vacuole-like reservoir. The refractile elements inside the cell are polysaccharide storage granules (paramylon) Elongate, anterior slightly trumpet-like with one emergent flagellum. Not often encountered. Differential interference contrast.

Cyclidiopsis (sigh-clid-ee-op-sis) is a colourless heterotrophic euglenid, but is unusual in that it has an eyespot. Elongate, anterior slightly trumpet-like with one emergent flagellum. Not often encountered. This is a dividing cell. Phase contrast.