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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Peranema

Peranema Dujardin, 1841 (ref. ID; 4656, 4950) reported year? (ref. ID; 1618)

Order Heteronematales (ref. ID; 4826)
Euglenida Butschli, 1884 (ref. ID; 4872)

[ref. ID; 1618]
Elongate, with a broad rounded or truncate posterior end during locomotion; highly plastic when stationary; delicate pellicle shows a fine striation; expansible cytostome with a thickened ridge and two oral rods at anterior end; aperture through which the flagella protrude is also at anterior end; a free flagellum, long and conspicuous, tapers toward free end; a second flagellum adheres to the pellicle; nucleus central; a contractile vacuole, anterior, close to the reservoir; holozoic; fresh water. (ref. ID; 1618)
  1. Peranema asperum Playfair (ref. ID; 4950)
  2. Peranema asperum var. rectangulare Playfair (ref. ID; 4950)
  3. Peranema cuneatum Playfair, 1921 (ref. ID; 4656) reported year? (ref. ID; 4950)
  4. Peranema curvicauda Skuja (ref. ID; 4950)
  5. Peranema deflexum Skuja (ref. ID; 4950)
  6. Peranema furcatum Skvortzow (ref. ID; 4950)
  7. Peranema fusiforme Larsen, 1987 (ref. ID; 4872)
  8. Peranema glabrum Van Oye (ref. ID; 4950)
  9. Peranema granulifera Penard (ref. ID; 1618, 4950)
  10. Peranema granuliferum Penard (ref. ID; 3517)
  11. Peranema inflexum Skuja (ref. ID; 4950)
  12. Peranema kupfferi Skuja (ref. ID; 4950)
  13. Peranema macromastix Conrad (ref. ID; 4950)
  14. Peranema macrostoma Ekebom, Patterson & Vors, 1995/96 (ref. ID; 4872 original paper)
  15. Peranema ovale Lackey (ref. ID; 4950)
  16. Peranema pleururum Skuja (ref. ID; 4950)
  17. Peranema trichophorum Ehrenberg, 1838 (ref. ID; 4656) reported year? (ref. ID; 1618) or (Ehrenberg, 1832) Stein, 1878 (ref. ID; 4872) (ref. ID; 3342, 3517, 4092, 4950) reported author and year? (ref. ID; 4826)

Peranema fusiforme Larsen, 1987 (ref. ID; 4872)

Descriptions

Cell usually narrow spindle-shaped when gliding, but metabolic and more expanded when squirming. With 40-45 delicate pellicular stripes running counter-clockwise. Globular extrusions sometimes aligned along the striations. Two flagella of unequal length emerge from the slit-like opening of the flagellar canal. Anterior flagellum as long as the cell of slightly longer, posterior flagellum short, curved and does not extend as far as the ingestion apparatus. The anterior opening of the flagellar canal is surrounded by a small collar. Flagellar pocket is located in the first quarter of the cell on the left side. Ingestion apparatus with two rods, which are sometimes hard to see and sometimes very obvious. They narrow towards their posterior ends. Anterior part of the rods with cap-like swellings. Nucleus often in the posterior part of the cell. (ref. ID; 4872)

Remarks

Shape, size, striations, location of nuclei and short recurrent flagellum correspond well with the description of Peranema fusiforme by Larsen (1987) and by Larsen & Patterson (1990). We note that with most cells being 25-30 um, the organisms observed here are a little smaller. We also note that in Larsen & Patterson (1990) the ingestion apparatus is small. In some of the cells observed here the rods were strong and prominent -similar in relative proportions to those of P. macrostoma. One large cell was observed by Larsen & Patterson (1990) and referred to as P. fusiforme. We also observed one cell extending to 90 um long when gliding. It closely resembled P. fusiforme in having a short recurrent flagellum, delicate ingestion rods, and fine refractile granules alongside the pellicular striation. It also had filaments within the flagellar pocket. No other cells intermediate in size between 45 um and these large individuals were observed. With the description of another species with a short recurrent flagellum, and because of the general failure of early studies (reviewed in Hubert-Pestalozzi 1955) to properly record the presence and/or nature of the recurrent flagellum (Larsen 1987) the genus Peranema merits further attention to resolve specific identities. (ref. ID; 4872)

Measurements

Cell length 35 um, range 25-45 um. (ref. ID; 4872)

Peranema granulifera Penard (ref. ID; 1618, 4950)

Descriptions

Much smaller in size; elongate, but plastic; pellicle granulated; standing water. (ref. ID; 1618)

Measurements

8-15 um long. (ref. ID; 1618)

Peranema macrostoma Ekebom, Patterson & Vors, 1995/96 (ref. ID; 4872 original paper)

Diagnosis

Species 64-87 um long, with short curved recurrent flagellum and substantial ingestion rods 1-2 um in diameter and about 1/5 times of the length of the cell. (ref. ID; 4872)

Descriptions

Cell elongate but tapered anteriorly when gliding freely, but highly metabolic and adopting a more expanded form when gently compressed. With about 50 tightly packed pellicular stripes. Rod-shaped extrusions, (bacteria/extrusomes?) may lie adjacent and internal to the stripes. Anterior end narrowed with a tubular flagellar canal, the posterior end of the cell rounded. The anterior apex appears rigid, projecting even when cell is fully contracted. The flagellar pocket is on the left ventral side. The anterior flagellum is thick and varies from about one to one and a half times the length of the cell. The posterior flagellum is about 1/5-1/6 of the cell in length, emerging from the posterior end of the slit-like opening of the flagellar canal. With a strongly developed ingestion apparatus with two broad rods located slightly to the right in the anterior end of the cell. Each rod is 1-2 um in diameter and 12-15 um long. The anterior ends of the rods are swollen and they look alike thick drum sticks. The nucleus is located in the posterior end of the cell. Cell glide with a squirming motion by stretching the anterior end forward and drawing the main part of the cell forward. Refractile granules may be randomly distributed inside the cell, sometimes in very large numbers to giving the cells a glistening appearance. (ref. ID; 4872)

Remarks

Until now, P. fusiforme is the only species is this genus which has been described with a short recurrent flagellum similar to that of P. macrostoma (Huber-Pestalozzi 1955; Larsen 1987; Larsen & Patterson 1990). There is also some similarity between the organisms described here and with some earlier descriptions of P. trichophorum but we hold that P. trichophorum is characterized by having a recurrent flagellum running virtually the length of the cell in a groove. The ingestion apparatus of P. macrostoma is relatively more substantial than in P. fusiforme or P. trichophorum. As P. fusiforme is usually much shorter than P. macrostoma, being only 35-45 um long, we regard P. macrostoma as a previously undescribed species. We note that Larsen & Patterson (1990) report a single cell of P. fusiforme at 70 um, and this may have been a record of P. macrostoma. (ref. ID; 4872)

Measurements

Cell length about 75 um, range 64-87 um. (ref. ID; 4872)

Peranema trichophorum Ehrenberg, 1838 (ref. ID; 4656) reported year? (ref. ID; 1618) or ((Ehrenberg, 1832) Stein, 1878 (ref. ID; 4872) reported year? (ref. ID; 3342, 3517, 4092, 4950) reported author and year? (ref. ID; 4826)

Descriptions

Body ordinarily filled with paramylum or starch grains derived from Astasia, Rhabdomonas, Euglena, etc., which coinhabit the culture; holozoic; very common in stagnant water. (ref. ID; 1618)
Cell sac-shaped, often slightly twisted and metabolic. There are longitudinal pellicular stripes that may have small rod-like bodies alongside. The posterior end of the flagellar pocket slightly curved to the right. Flagellar canal with a slit-like opening that extends from the apex backwards for about 1/10 of the cell length. A longitudinal groove extends from the slit to the posterior end, and the recurrent flagellum lies within this groove. The anterior end of the cell is pointed, the posterior end is truncated occasionally with an irregularity marking the posterior termination of the longitudinal groove. The anterior flagellum has the same length as the cell or it is slightly longer, 1-1+1/2 um thick, often with the basal part in contact with substratum, damping the movements of the anterior flagellum. Ingestion apparatus with two rods. Cell glides in close contact with the substrate. (ref. ID; 4872)

Remarks

Our observations were in agreement with the descriptions given by Larsen (1987) and Larsen & Patterson (1990). However, the species has a confused identity, with lengths reported from 22 to 81 um, and with or without a recurrent flagellum, with or without surface striations, with or without an irregular posterior end (Huber-Pestalozzi 1955; Leedale 1967; Lemmermann 1914; Skuja 1939; Stein 1878). Much more extensive study is needed to clarify the situation. (ref. ID; 4872)

Measurements

40-70 um long. (ref. ID; 1618)
65x13.5 um. (ref. ID; 3342)
Cell length about 42 um, range 35-50 um. (ref. ID; 4872)