Coleps hirtus (Nitzsch, 1817)
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Simmelried, Purren pond, Mainau pond, Bussenried, Bündtlisried, Ulmisried, Mühlhalden pond
Phylogenetic tree: Coleps hirtus
Diagnosis:
- length 40–65 µm
- cell barrel-shaped
- CV terminal
- uniform ciliation
- 15–20 longitudinal rows of plates
- one caudal cilium
- macronucleus spherical
- apical mouth opening with basket
- three spines at posterior end
- shape of the “windows” in the carapace are pretzel-shaped
Coleps hirtus is one of the most common ciliates ever. I find it throughout the year in all my localities. With low magnifications (< Obj. 40X) the identification can be difficult. Confusion with other Coleps species is then not impossible. Therefore you have to look closely at the fielding of the carapace with the 100 X objective. Coleps hirtus has clearly pretzel-shaped windows in the carapace. Also, the number of caudalcilia should be checked in any case. There should be only one caudal cilium.
Fig. 1 a-c: Coleps hirtus. L = 67 µm. A freely swimming specimen. CC = caudal cilium. Obj. 40 X.
Fig. 2 a-d: Coleps hirtus. L = 62 µm. A second freely swimming specimen. CC = caudal cilium, SP = posterior spines. Obj. 100 X.
Fig. 3 a-c: Coleps hirtus. L = 71 µm. A third freely swimming specimen. ASP = apical spines, CC = caudal cilium, MO = mouth opening. Obj. 100 X.
Fig. 4: Coleps hirtus. Two focal planes on the carapace of a squashed specimen. Obj. 100 X.
Fig. 5: Coleps hirtus. The pretzel-shaped “windows”(PW) in the carapace of a squashed specimen. Obj. 100 X.