Euglenophyceae

Euglena gracilis. Cell observed in freshwater habitats in the vicinity of Broome, Western Australia in September 2003. This image was taken using differential interference contrast optics.   This work was supported by the Australian Biological Resources Study.

Whole cell, the dark eyespot is near the front and adjacent to it is the flagellar pocket / reservoir / contractile vacuole region. the nucleus is the clear structure near the posterior of the cell. The positions of about 6 large plastids can be worked out. Animations by Rosemary Arbur of flagellar beat patterns are available here.

Euglena mutabilis (you-glean-a mew-tab-ill-iss) is one of the worm-like species of Euglena. Typically there is no emergent flagellum or a very short one. Yet, the organism can be distinguished as a euglenid because of the bright green plastids, the eyespot that lies external to any plastid, and because the cells can squirm. The plastids are large-ish plate like structure which wrap themselves around the cell adjacent to the pellicle. The margins of individual plastids are hard to distinguish in this micrograph. Differential interference contrast.

Euglena mutabilis (you-glean-a mew-tab-ill-iss), is a moderately long but usually thin worm-like euglena. It may or may not have an emerging flagellum, and distinguished from similarly-shaped species by the relatively small number of large chloroplasts - about four can be clearly made out in this cell. The image also shows (from anterior - top): stigma or eyespot, flagellar pocket, and nucleus in the middle of the cell. Typically very metabolic - squirming a lot. Differential interference contrast.

Euglena mutabilis is a worm like gliding Euglena which rarely swims. Sizes vary from 53-206 microns long, with 10 or more (up to 100), disk-shaped, plastids situated just below surface. It is distinguished from another worm like species (E. mutabilis) by the much larger number of plastids. The cells contain small rod and oval-shaped paramylon bodies scattered throughout the cytoplasm. Anterior flagellum usually about a quarter of the cell length, but may not be emergent, or be a short stump, or up to 0.5 the cell length. There are two flagella inserting in the flagellar pocket which can be seen behind the red stigma or eyespot. May produce cysts. The large tapioca-like nucleus is located just behind the mid line. Surface striations not visible. Metabolic (can squirm). Differential, interference contrast.

Euglena mutabilis is a worm like gliding Euglena which rarely swims. With more than 10 (up to 100), disk-shaped, plastids situated just below surface. It is distinguished from another worm like species (E. mutabilis) by the much larger number of plastids. Plastids are disc shaped. Also evident at the front of the cell is the emergent flagellum, the flagellar canal, the stigma, and flagellar pocket. Differential interference contrast.

Euglena mutabilis (you-glean-a mew-tab-ill-iss), is a moderately long but usually thin worm-like euglena. It may or may not have an emerging flagellum, and distinguished from similarly-shaped species by the relatively small number of large chloroplasts. The image also shows (from anterior - top): flagellar pocket, stigma or eyespot, small paramylon granules, and nucleus in the middle of the cell. Typically very metabolic - squirming a lot as is suggested by the different profiles in this image. Phase contrast.

Euglena mutabilis (you-glean-a mew-tab-ill-iss), is a moderately long but usually thin worm-like euglena. It may or may not have an emerging flagellum, and distinguished from similarly-shaped species by the relatively small number of large chloroplasts. The image also shows (from anterior - top): flagellar pocket, stigma or eyespot, small paramylon granules, and nucleus in the middle of the cell. Typically very metabolic - squirming a lot. Differential interference contrast.

Euglena mutabilis (you-glean-a mew-tab-ill-iss), is a moderately long but usually thin worm-like euglena. It may or may not have an emerging flagellum, and distinguished from similarly-shaped species by the relatively small number of large chloroplasts. The image shows the palmelloid mass that can be formed under some circumstances. Many hundred or thousands of cells form a skin, or film or mass in which the individual cells are embedded in a common matrix. Cells will become more active and work their way out of the mass when they are disturbed. Phase contrast.

Euglena mutabilis. Cell observed in freshwater habitats in the vicinity of Broome, Western Australia in September 2003. This image was taken using differential interference contrast optics.   This work was supported by the Australian Biological Resources Study.

Euglena mutabilis. Cell observed in freshwater habitats in the vicinity of Broome, Western Australia in September 2003. This image was taken using differential interference contrast optics.   This work was supported by the Australian Biological Resources Study.

Euglena mutabilis. Cell observed in freshwater habitats in the vicinity of Broome, Western Australia in September 2003. This image was taken using differential interference contrast optics.   This work was supported by the Australian Biological Resources Study.

Two cells of this worm-like species of euglena. These cells have no emerging flagella, and they move by squirming and gliding. The cell contains numerous chloroplasts, and these provide the cell with their green colour. The red dots are the eye-spots.

Euglena oblonga. Cell observed in freshwater habitats in the vicinity of Broome, Western Australia in September 2003.  This work was supported by the Australian Biological Resources Study.

Euglena oxyuris (you-glean-a ox-ee-your-is), is a moderate to large euglena, with a stiff pellicle that has well developed ridges. Flagella can be short. Although it can squirm it is not very actively metabolic. With large numbers of small plastids. This image is of a flattened cell, and it shows from front (left) to back: entrance to flagellar canal, eyespot, light region of the flagellar pocket, link-shaped paramylon grain, smaller paraymyloin grains, plastids and nucleus. The ridges of the pellicle are superimposed. Differential interference contrast.

Euglena oxyuris (you-glean-a ox-ee-your-is), is a moderate to large euglena, with a stiff pellicle that has well developed ridges, and often - as we can see here - with a fold in the cell. Flagella can be short. Although it can squirm it is not very actively metabolic. With large numbers of small plastids. This image shows, one large -link-shaped element of paramylon, the pellicular ridges around the edge of the cell to the right, and the nucleus. Differential interference contrast.

Euglena oxyuris (you-glean-a ox-ee-your-is), is a moderate to large euglena, with a stiff pellicle that has well developed ridges. Flagella can be short. Although it can squirm it is not very actively metabolic. With large numbers of small plastids. This cell has been stained with DAPI, a dye which binds to DNA and fluoresces blue-white. It reveals the large nucleus - bottom right. Fluorescence.

Euglena oxyuris (you-glean-a ox-ee-your-is), is a moderate to large euglena, with a stiff pellicle that has well developed ridges. Flagella can be short. Although it can squirm it is not very actively metabolic. With large numbers of small plastids. This cell was illuminated using high energy ultraviolet light and the red autofluorescence then photographed. The fluorescence comes from the chlorophylls in the chloroplast and so we can use this to get a sense of the number and size of the plastids. Fluorescence.

Euglena oxyuris (you-glean-a ox-ee-your-is), is a moderate to large euglena, with a stiff pellicle that has well developed ridges. Flagella can be short. Although it can squirm it is not very actively metabolic. With large numbers of small plastids. This cell was illuminated using high energy ultraviolet light and the green autofluorescence then photographed. Fluorescence.

Euglena oxyuris (you-glean-a ox-ee-your-is), is a moderate to large euglena, with a stiff pellicle that has well developed ridges, and often - as we can see here - with a fold in the cell. Flagella can be short. Although it can squirm it is not very actively metabolic. With large numbers of small plastids. Large red eyespot near the anterior (right). Differential interference contrast.

Euglena oxyuris, one of the larger (but not largest) euglenids, broad front end, and with a posterior spike. No emergent flagellum, moves by gliding across the substrate. With obvious red eye spot and large paramylon granules. Differential interference contrast.

Euglena oxyuris, one of the larger (but not largest) euglenids, broad front end, and with a posterior spike. No emergent flagellum, moves by gliding across the substrate. With obvious red eye spot and large paramylon granules. This image is of the pellicle, showing the folded nature that is distinctive for euglenids. Differential interference contrast.

One of the larger species in the genus. The cortical region of the cell is thick and thrown into fine folds. There are several large rod-like paramylon granules, ovoid nucleus, and dark red spot near the front of the cell. There is no emergent flagellum. Nomarski optics.

Euglena tripteris, elongate swimming euglenid, distinguished by triangular body profile in cross-section. Image shows elongate paramylon granules, and anterior eyespot. From freshwater pond near Boise, Idaho.