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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Pentamonas

Pentamonas Lackey, 1962 (ref. ID; 3090 original paper)

[ref. ID; 3090]
There is no description of any colorless englenid having laterally projecting spinous processes. Even in Trachelomonas, the spines are projections from the shell, not the pellicle. The organism is one of the many euglenids having highly characteristically sculptured pellicles. The organism seems to have no close relative among the colorless euglenids. Paramylum and the gullet-reservoir system indicate its broad affinities; the spinous projections of the pellicle seem to justify creation of a new genus. It is given its generic name because of the typical five pointed, five sided shape, and is proposed as the type species with generic and species characteristics given above. (ref. ID; 3090)
  1. Pentamonas spinifera Lackey, 1962 (ref. ID; 3090 original paper)

Pentamonas spinifera Lackey, 1962 (ref. ID; 3090 original paper)

Descriptions

In shape it is an irregular short oval, dorso-ventrally flattened. The edges of the firm pellicle are produced on the right and posterior sides into three or four backward curved spinous processes. Sometimes the left edge has a spine toward the anterior end, but usually there is a sharp angular point there instead of a spine. The typical number of spines is four, but rarely one with three spines may be found. Sometimes the left side lacks the angular point, and becomes an outward curve. The cell is dorsoventrally flattened, about 10 um thick. Usually two or more small ridges extend from the area of the mouth back towards the posterior spines. Otherwise the pellicle is smooth and quite firm. The mouth is circular and terminal. It may even be slightly protruded, appearing snout-like. The gullet-reservoir is typical and rather short, about 7-9 um deep. No vacuole has been seen. There is no staborgan. The nucleus lies close to the base of the gullet-reservoir, an unusual position for euglenids. It is small, with no observed endosome. The cytoplasm is variously vacuolated and contains characteristic small rods of paramylum and small spheres with appear to be lipids, blackening with osmic acid. One unusual feature is commonly a large clear vesicle or vacuole (never seen to contract) toward the left rear. Its presence is anomalous since no observed function was noted. There is one flagellum, which tapers slightly, and whose movements are irregular. It is about three quarters cell length. The organism crawls among and over sand grains on a slide. It is saprozoic. Division stages were not seen. (ref. ID; 3090)

Type locality

The type location is designated as the intertidal sand at the Narragansett Marine Laboratory, Kingston, Rhode Island, USA. (ref. ID; 3090)