Peranemidae

Heteronema(het-err-owe-knee-ma) globuliferum (Ehrenberg, 1838) Stein, 1878. Cell outline is elongate to ovate. Cells are 15 - 30 microns long and about 8 to 11 microns wide, flattened, with squirming movement and with pellicular striations following a S-helix. Two emergent flagella are similar in width. The anterior flagellum is approximately 2 to 2.5 times the length of the cell and is longer than the posterior flagellum, which is slightly longer than the cell. The ingestion organelle may be difficult to see. The reservoir is in the left ventral side of the cell and the nucleus is in the posterior part of the cell. Refractile bodies lie under the cell surface. The cells move by gliding.

Heteronema globuliferum (Ehrenberg, 1838) Stein, 1878. Cell outline is elongate to ovate. Cells are 15 - 30 microns long and about 8 to 11 microns wide, flattened, with squirming movement and with pellicular striations following a S-helix. Two emergent flagella are similar in width. The anterior flagellum is approximately 2 to 2.5 times the length of the cell and is longer than the posterior flagellum, which is slightly longer than the cell. The ingestion organelle may be difficult to see. The reservoir is in the left ventral side of the cell and the nucleus is in the posterior part of the cell. Refractile bodies lie under the cell surface. The cells move by gliding.

Heteronema hexagonum (Playfair) Skuja, 1948. Cells are about 30 microns long and 18 microns wide. Irregularly hexagonal, central part subquadrate, above and below triangular-conical, ends pointed, sides straight, transversely striate, apparently on one side only, two flagella, one trailing

Heteronema hexagonum elegans (Playfair, 1921) Lee Cells are about 40 microns long and 10 microns wide. The same general shape as Anisonema hexagonum, but longer and more slender.

Heteronema scaphurum Skuja, 1934. Gliding metabolic euglenid, cell spindle-shaped, 62 -75 microns long. Anterior part of cell is a short narrow cylinder. The canal-opening is oblique, posterior end of cell is truncate with a obvious dimple (2.5 -3 microns deep) at the end. The pellicle has widely spaced ridges following an S-helix which may be occasionally discontinuous. The anterior flagellum is about 1-2 cell length and the recurrent flagellum is slightly less than 1.0 cell length. A large roundish nucleus is located in the middle of the cell. The ingestion apparatus has two short weakly developed rods. A contractile vacuole empties into the base of the flagellar pocket.

Peranema (pear-o-knee-ma) is one of the better known gliding heterotrophic euglenids. The body is referred to as sac-shaped but this applies best to P. trichophorum, the most common species and the one illustrated here. At first glance, it would seem that there is just one flagellum, but careful observations reveal a second flagellum tightly adpressed to the body or lying in a groove in the body surface. At magnifications such as this, this species usually cannot be distinguished from Jenningsia, which has a single flagellum. The recurrent structure looks a little wider than the normal ridges of the body. The body is metabolic - meaning it squirms, and members of this genus have an ingestion organelle with which to manipulate food into the body. Differential interference contrast.

Portrait of a relatively large (116 microns long) species of Peranema, a common colorless phagotrophic euglenid flagellate. Peranema possesses two flagella but the shorter trailing flagellum is adherent to the body and not ordinarily seen. The thick anterior flagellum is characteristically held straight in with only the distal tip beating. The cell body is elongate and quite plastic exhibiting euglenoid metaboly when not swimming. The posterior end may be truncate or pointed. The anterior reservoir with adjacent contractile vacuole can be seen in this image. The reservoir and its apical opening are separate from the subapical cytostome and the two supporting rods of the ingestion apparatus. These anterior rods are well seen in this image. Pellicular striations are also evident. A prominent nucleus is visible at the junction of the middle and posterior thirds of the cell. From freshwater pond near Boise, Idaho. Brightfield illumination.

Peranema is a euglenid without chloroplasts. This species moves with a thick flagellum sticking out in front. It eats debris and other protists. Animations by Rosemary Arbur of flagellar beat patterns are available here.

Peranema. Collected by ATOL team in Little Sippiwisset near to Woods Hole, Massachusetts during the Protistology Workshop at MBL. October-November 2005. Isolation and art by Adrian Reyes-Prieto.

Peranema (pear-o-knee-ma) is one of the better known gliding heterotrophic euglenids. The body is referred to as sac-shaped but this applies best to P. trichophorum, the most common species and the one illustrated here. At first glance, it would seem that there is just one flagellum, but careful observations reveal a second flagellum tightly adpressed to the body or lying in a groove in the body surface. At magnifications such as this, this species usually cannot be distinguished from Jenningsia, which has a single flagellum. The recurrent structure looks a little wider than the normal ridges of the body. The body is metabolic - meaning it squirms, and members of this genus have an ingestion organelle with which to manipulate food into the body. Animations by Rosemary Arbur of flagellar beat patterns are available here.Differential interference contrast.

Peranema (pear-o-knee-ma) is one of the better known gliding heterotrophic euglenids. The body is referred to as sac-shaped but this applies best to P. trichophorum, the most common species and the one illustrated here. At first glance, it would seem that there is just one flagellum, but careful observations, especially at high magnifications, reveal a second flagellum tightly adpressed to the body or lying in a groove in the body surface. The recurrent structure looks a little wider than the normal ridges of the body. The body is metabolic - meaning it squirms, and members of this genus have an ingestion organelle with which to manipulate food into the body. Differential interference contrast.

Peranema (pear-o-knee-ma) is one of the better known gliding heterotrophic euglenids. The body is referred to as sac-shaped but this applies best to P. trichophorum, the most common species and the one illustrated here. At first glance, it would seem that there is just one flagellum, but careful observations reveal a second flagellum tightly adpressed to the body or lying in a groove in the body surface. At magnifications such as this, this species usually cannot be distinguished from Jenningsia, which has a single flagellum. The recurrent structure looks a little wider than the normal ridges of the body. The body is metabolic - meaning it squirms, and members of this genus have an ingestion organelle with which to manipulate food into the body. Phase contrast.

Peranema (pair-a-knee-ma) trichophorum (Ehrenberg, 1830) Stein, 1878. Cells are metabolic and 35 to 50 microns long, have longitudinal pellicular striations around the cell. The anterior end of the cell is slightly pointed and the posterior end is truncated, rounded, or indented. This body is slightly curved and the flagellar pocket is also to the right. The flagellar pocket including the flagellar canal is up to 40 % the length of the cell. The anterior flagellum is as long as the cell, is thick and is directed forward when the cell is moving. The posterior flagellum may be hard to observe, is thin, and tightly adpressed to the cell surface, lying in a narrow longitudinal groove. The ingestion organelle has two rods and is weakly developed. The nucleus is posterior to the centre of the cell. The cells glide in contact with the substratum. Relatively common.

Peranema trichophorum (Ehrenberg, 1830) Stein, 1878. Cells are metabolic and 35 to 50 microns long, have longitudinal pellicular striations around the cell. The anterior end of the cell is slightly pointed and the posterior end is truncated, rounded, or indented. This body is slightly curved and the flagellar pocket is also to the right. The flagellar pocket including the flagellar canal is up to 40 % the length of the cell. The anterior flagellum is as long as the cell, is thick and is directed forward when the cell is moving. The posterior flagellum may be hard to observe, is thin, and tightly adpressed to the cell surface, lying in a narrow longitudinal groove. The ingestion organelle has two rods and is weakly developed. The nucleus is posterior to the centre of the cell. The cells glide in contact with the substratum.

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

Peranema trichophorum. Surface of a 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.

Gliding Peranema cell. One thick flagellum pprojects from the front of the cell. There is a second flagellum - but it lies close to the cell surface and can only be seen with careful observation. It is not visible in these two cells. The cell on the surface of the air bubble is seen from side view. Phase contrast microscopy

The two rods of the phagotrophic apparatus revealed by immunofluorescence microscopy (from A. Belhadri & G. Brugerolle).

Nomarski image of living gliding cells. There are two flagella, but only one is visible, the other adheres to the surface of the cell. The rods of the ingestion apparatus are visible just behind the anterior end of the cell. Animations by Rosemary Arbur of flagellar beat patterns are available here.

Peranema cuneatum Playfair, 1921. Cells are metabolic, 25-70 microns long and 5-15 microns wide. When free-swimming, it is cuneate, sharp-pointed in front and abruptly truncate behind, one corner is sometimes produced as a pointed tail directed backwards, or a blunt wart-like prominence often bifid and placed to one side. A minute stigma has been reported as occurring occasionally. Cytoplasm homogeneous and transparent. Fig 7 of Plate 9 in Playfair (1921) appears to be Jenningsia fusiforme and Fig 9 of Plate 8 appears to be Peranema trichophorum.