Lepocinclis oxyuris
(Schmarda) B. Marin & Melkonian, 2003
Most likely ID: n.a.
Synonym: Euglena oxyuris
Sampling location: Ulmisried, Simmelried, Purren pond
Phylogenetic tree: Lepocinclis oxyuris
Diagnosis:
- body elongated, cylindrically with parallel sides, with three twisted keels
- anterior end rounded, posterior end with tapered tailpiece
- length 136–490 µm
- flagellum one-third of body length
- striation of pellicle in double lines (alternating thin and broad lines)
- striation of pellicle twisted clockwise
- eyespot slightly granular, medium sized
- chloroplast disc-shaped
- oval or ellipsoid nucleus central
- commonly 2 large, oblong paramylon grains (sometimes up to 20)
I regularly find Lepocinclis oxyuris in the uppermost mud layer of some of my sampling sites. This large species is particularly common in the Simmelried.
In the fresh samples, Lepocinclis oxyuris stands out even at small magnifications due to its size and the characteristic tailpiece. The cylindrical body is also twisted in a clockwise direction. At higher magnification, two large paramylon grains are usually found, which are arranged above and below the nucleus (s. fig. 3 a). Sometimes, however, specimens with more than two of these large paramylon grains are found. Depending on the degree of nutrition, these paramylon grains can also look thin and rod-shaped. An interesting and constant characteristic of Lepocinclis oxyuris is the striation of the pellicle. This consists of double lines. Broad and thin lines alternate here (s. fig. 3 c). In addition, the striation in Lepocinclis oxyuris is twisted clockwise, which is rare within the euglenids.
Fig. 1 a-d: Lepocinclis oxyuris. L = 235 µm. A freely swimming specimen. Obj. 40 X.
Fig. 2 a-c: Lepocinclis oxyuris. L = 216 µm. Different focal planes of a slightly squashed specimen. Chl = disc-shaped chloroplasts, ES = eyespot, F = flagellum, Nu = nucleus. Obj. 60 X.
Fig. 3 a-c: Lepocinclis oxyuris. Different focal planes of the squashed specimen as shown in fig. 2 a-c. Note the two oblong shaped paramylon grains (PG) above and below the nucleus (Nu). In the cytoplasm some haematochrome granules (HG) are present. The numerous chloroplasts (Chl) are disc-shaped. The striation of the pellicle (PS) consists of alternating broad and thin lines and is twisted clockwise. Obj. 100 X.
Fig. 4: Lepocinclis oxyuris. The rounded anterior end in detail. Note the contractile vacuole (CV) adjacent to the reservoir (RE). CP = cytopharynx, ES = eyespot, Nu = nucleus, PG = paramylon grain. Obj. 100 X.