(Linnaeus, 1758) Ehrenberg, 1830
Most likely ID: n.a.
Sampling location: Simmelried
Phylogenetic tree: Carchesium polypinum
- zooids elongated bell-shaped, often inclined to the side
- length of zooids 80–140 µm
- zooids contract almost spherical
- macronucleus J-shaped in the longitudinal axis
- one micronucleus
- one contractile vacuole
- peristome collar 60–135 µm in diameter
- pellicle finely striated
- colonies tree-shaped with branched stalks, up to 2 mm heigh
- lower part of the colonies is an unbranched main stem
- stalks contract in tight helix
- myonemes in the branches are interrupted
I find Carchesium polypinum mainly in old samples from the Simmelried. The colonies of this pertrich ciliate are easy to recognize by the tree-like structure and the non-branched stalk. Carchesium polypinum can be easily distinguished from other colony-forming peritriche ciliates, whose peduncles also contract helically, by the interrupted myonemes at the branching points (s. figs. 3, 4 and 5). This interruption of myonemes causes zooids and also individual branches of colonies to contract independently. In the similar genus Zoothamnium, the myonemes are not interrupted, causing the entire colony to always contract synchronously. A distinguishing feature from Vorticella species is the stalk thickness. In Vorticella, the stalk is always < 10 µm thick, whereas in Carchesium polypinum it is thicker than 10 µm (s. fig. 6). Comparable Epistylis species (e.g. Epistylis procumbens) do not have a central myoneme in the stalk and therefore cannot contract.
Fig. 1: Carchesium polypinum. Overview of a colony with a length of 1600 µm. Obj. 10 X.
Fig. 2: Carchesium polypinum. Detail of the colony shown in fig. 1. Obj. 20 X.
Fig. 3: Carchesium polypinum. L = 90–106 µm (of zooids). The zooids of the colony shown in fig. 1. Note the interrupted myoneme (IM) at the branch of the stalk. Obj. 40 X.
Fig. 4: Carchesium polypinum. The interrupted myoneme (arrow) at the branch of the stalk in a slightly squashed colony. Obj. 40 X.
Fig. 5: Carchesium polypinum. The interruption of the myoneme (IM) in detail. My = myoneme of the stalk. Obj. 40 X.
Fig. 6: Carchesium polypinum. The spiralized stalk with the central myoneme (MY). The myoneme is surrounded by numerous mitochondria (Mit). Obj. 100 X.
Fig. 7: Carchesium polypinum. The fine sriation of the pellicle. In this specimen, there are 15 lines per 10 µm. AW = aboral ciliary wreath. Obj. 100 X.
Fig. 8: Carchesium polypinum. The J-shaped macronucleus (Ma) and the micronucleus (Mi) in a strongly squashed specimen. CV = contractile vacuole. Obj. 100 X.