Asplanchna girodi (de Guerne, 1888)
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Pond of the waste disposal company Constance
Phylogenetic tree: Asplanchna girodi
Diagnosis:
- body sac-shaped, transparent and flexible
- well developed corona
- length 500–700 µm
- vitellarium horseshoe-shaped
- nucleoli of nuclei in yolk glands rounded (not lobed)
- yaws of trophi without teeth
- no apophysis at base of rami
- one cerebral eyespot
- foot absent
- intestine absent
- planktonic lifestyle
So far I have only found Asplanchna girodi in the pond of the waste disposal company in Constance, which is highly eutrophic. The species often occurs in parallel with Asplanchna priodonta. However, these two species can be easily distinguished by the shape of the vitellarium. In Asplanchna priodonta it is globular, whereas in Asplanchna girodi it is horseshoe-shaped. However, Asplanchna brightwelli also has this shape of U-shaped vitellarium. Finally, to differentiate between these two species the trophi have to be investigated, which is smooth and without teeth in Asplanchna girodi, while a distinct teeth are present in the middle of the rami in Asplanchna brightwelli. In addition, there are clear apophyses at the basal end of the trophi in Asplanchna brightwelli. These are outwardly directed teeth at the basal end of the rami.
More images and information on Asplanchna girodi: Michael Plewka-Freshwater life-Asplanchna girodi
Fig. 1: Asplanchna girodi. L = 520 µm. A sligthly squashed specimen. Note the U-shaped vitellarium (Vit, only partly visible). Obj. 40 X.
Fig. 2: Asplanchna girodi. L = 580 µm. A second sligthly squashed specimen. BL = bladder, ES = cerebral eyespot, EO = esophagus, GG = gastric glands, St = stomach, Vit = vitellarium. Obj. 40 X.
Fig. 3: Asplanchna girodi. A squashed specimen with a slightly deformed vitellarium (Vit). Note the large, rounded nucleoli (Nuc) in the nuclei (Nu) of the vitellarium. BL = bladder, GG = gastric glands, St = stomach. Obj. 40 X.
Fig. 4: Asplanchna girodi. A second squashed specimen with focal plane on the vitellarium (Vit) and two embryos (EM) in different states of development. GG = gastric glands, St = stomach, TR = trophi. Obj. 40 X.
Fig. 5: Asplanchna girodi. The stronger squashed specimen as shown in fig. 4. The corona (CO) is flattened and the trophi (TR) become visible. Obj. 40 X.
Fig. 6: Asplanchna girodi. The trophi in detail. The rami are smooth without any teeth. Obj. 100 X.
Fig. 7: Asplanchna girodi. L = 228 µm. A male specimen with a rudimentary digestive systeme (RDS). The testis (TE) is filled with sperm cells (SC). PE = penis. Obj. 40 X.