Colurella uncinata Müller, 1773
Most likely ID: n.a.
Synonym: n.a.
Sampling location:Mainau pond, Ulmisried, Simmelried
Phylogenetic tree: Colurella uncinata
Diagnosis:
- lorica oval with posterior spine, laterally compressed
- length (of lorica) 77–106 µm
- head with semi-circular shield, retractable
- foot with three segments
- two slender, pointed toes
- two lateral eyespots
I find Colurella uncinata in several of my sampling sites, but always sporadically. The specimens are usually found between floating plant masses.
The conspicuous spines at the posterior end of the lorica make it easy to distinguish Colurella uncinata from the more common species Colurella obtusa, which has a rounded posterior end. There are two spines, as each half of the lorical ends in a spine at the posterior end (s. drawings, above). Apically there is a movable, semi-circular head shield. This can open and close like a mussel shell. The lorica of Colurella uncinata is strongly flattened laterally, which makes observation from the ventral or dorsal side difficult.
Further information and images on Colurella uncinata: Michael Plewka-Freshwater life-Colurella uncinata
Fig. 1 a-c: Colurella uncinata. L = 111 µm (of lorica). A fully elongated specimen from left. Obj. 40 X.
Fig. 2 a-b: Colurella uncinata. L = 105 µm (of lorica). Two focal planes of a second, fully elongated specimen. Note the semi-circular head shield (HS) and the distinct posterior spine (PS). 1–3 = thee segments of the foot, TO = toes. Obj. 60 X.
Fig. 3 a-b: Colurella uncinata. L = 105 µm (of lorica). Lateral view of an elongated (a) and retracted (b) specimen from right. CO = corona, ES = eyespot, HS = head shield, PS = posterior spine. Obj. 100 X.