Mytilina bicarinata Perty, 1850
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Mindelsee
Phylogenetic tree: Mytilina bicarinata
Diagnosis:
- lorica long, laterally compressed, without spines
- dorsally two clearly separated keels
- length 126–250 µm
- last limb of the foot long
- one large eyespot
- pair of toes without claws
- unci with each 5 teeth
So far I have only found a few specimens of Mytilina bicarinata in February 2024 east of the Mindelsee. There is an extensive reed area there, in which temporary pools often form when the snow melts and in spring. This fits in with the information provided by Koste (1978) according to which Mytilina bicarinata is often found in temporary bodies of water.
Mytilina bicarinata has two clearly separated, large dorsal keels (name) which are only clearly recognizable in slightly squashed specimens (s. figs. 3 b and 4). Other important features are the elongated last limb of the foot (s. fig. 3 a) and the lack of claws on the relatively short toes (s. fig. 3 a). It also has a large eyespot below the cerebral ganglion.
Mytilina bicarinata differs from the similar species Mytilina bisulcata and Mytilina crassipes mainly by the large keels, the elongated foot limb and the lack of claws on the toes.
Fig. 1 a-b: Mytilina bicarinata. L = 232 µm. A freely swimming specimen from right. Obj. 40 X.
Fig. 2 a-b: Mytilina bicarinata. L = 232 µm. The slightly squashed specimen as shown in fig. 1 a-b from ventral. Obj. 40 X.
Fig. 3 a-b: Mytilina bicarinata. L = 232 µm. The slightly squashed specimen as shown in fig. 1 a-b from dorsal. Note the two dorsal keels (arrows), the elongated last limb of the foot (FT) and the pair of toes (TO) without claws. Obj. 40 X.
Fig. 4: Mytilina bicarinata. A second, slightly squashed specimen from dorsal with the two keels (arrows). Obj. 40 X.
Fig. 5: Mytilina bicarinata. Two focal planes of the trophi in a strongly squashed specimen. Note the each 5 teeth (1-5) of the unci (UN). Obj. 100 X.