Notholca squamula (Müller, 1786)
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Mindelsee
Phylogenetic tree: Notholca squamula
Diagnosis:
- lorica oval, dorso-ventrally flattened
- posterior end of lorica broadly rounded
- length 120–190 µm
- dorsal and ventral side of lorica with longitudinal striation
- anterior dorsal margin with 2 long and 4 short spines
- anterior ventral margin with an U-shaped sinus
- ohne spherical eyespot
So far I have only found Notholca squamula in the reedbeds of the Mindelsee. Temporary, very shallow pools form in the reedbeds there after the snow melts or after sufficient rainfall. As Notholca squamula is a cold-stenothermal species, I have only ever found it in February and March.
Notholca squamula is easily recognizable because the lorica is strongly flattened dorso-ventrally and broadly rounded at the posterior end. At the front end there is a U-shaped incision the ventral side (s. fig. 3 a), while on the anterior margin of the dorsal side there are two typical, elongated spines (s. fig. 3 b). The lorica consists of a ventral and dorsal plate, which are flexibly connected laterally. This allows the apical opening to close like a snap fastening glasses case when the animal retracts.
Fig. 1 a-c: Notholca squamula. L = 164 µm. A freely swimming specimen. Obj. 40 X.
Fig. 2 a-b: Notholca squamula. L = 168 µm. An elongated (a) and retracted (b) specimen. Obj. 60 X.
Fig. 3 a-b: Notholca squamula. L = 146 µm. Focal plane on the ventral plate of the lorica with a U-shaped incision (a) and on the dorsal plate with the two elongated spines in the middle (b). Note the longitudinal striation of the ventral and of the dorsal plate. Obj. 60 X.
Fig. 4: Notholca squamula. A squashed specimen from ventral. BL = bladder, ES = eyespot, GG = gastric glands, ST = stomach, TR = trophi, Vit = vitellarium. Obj. 60 X.
Fig. 5 a-b: Notholca squamula. Two focal planes of the trophi in a strongly squashed specimen. Obj. 100 X.