Cephalodella ventripes (Dixon-Nutall, 1901)
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Ulmisried
Phylogenetic tree: Cephalodella ventripes
Diagnosis:
- body stout and dorsally curved
- length 127–140 µm (with toes)
- large head with well marked neck fold
- lateral cleft narrows anteriorly
- corona oblique with two beak-like lips
- manubria are short, very slender and the ends strongly recurved,
- ganglion large and saccate with eyespot at posterior end
- eyespot a flat disc, doubled or with dividing furrow
- no retrocerebral organ
- toes ventrally curved with pointed ends
- foot short and conical shaped
So far I have found only one specimen of Cephalodella ventripes in floating plant masses from the Ulmisried. However, I cannot exclude that I missed the species earlier. Characteristic are the ventrally curved toes, which end pointed. The eyespot can be double and also with only one division furrow. It is also flat and disc-shaped (s. fig. 4). However, a definite classification of Cephalodella ventripes can only be made by a detailed examination of the trophi. The manubria of Cephalodella ventripes are curved in a characteristic sickle-shaped manner (s. fig. 5). As another special feature, Cephalodella ventripes possesses two beak-shaped processes, which are apically located in the corona (s. fig. 2 c). According to Plewka (2014), they serve to grasp small algal cells.
More images and information about Cephalodella ventripes: Michael Plewka-Freshwater life-Cephalodella ventripes
Fig. 1 a-d: Cephalodella ventripes. L = 147 µm (with toes). A slightly squashed specimen from ventral. The specimen was very flexible and agile. Obj. 40 X.
Fig. 2 a-d: Cephalodella ventripes. L = 147 µm (with toes). The same specimen as shown in fig. 1 a-c from left. Note the two bead-shaped lips (BL) of the corona. ES = eyespot, FT = foot, GA = ganglion, LA = lateral antenna, NF = neck fold, ST = stomach, TO = toes, Vit = vitellarium. Obj. 60 X.
Fig. 3: Cephalodella ventripes. L = 147 µm (with toes). Focal plane on the lateral cleft between the ventral and dorsal plate of the lorica. The cleft is narrows anteriorly (arrows). FT = foot, TO = toes. Obj. 60 X.
Fig. 4: Cephalodella ventripes. Focal plane on the flat, disc-shaped eyespot from ventral. Obj. 60 X.
Fig. 5: Cephalodella ventripes. The trophi in a strongly squashed specimen. Note the curved manubrium (Man), characteristic for this species. FU = fulcrum. Obj. 60 X.