Astasia granulata (Pringsheim, 1942)
Most likely ID: n.a.
Synonym: n. a.
Sampling location: Simmelried
Phylogenetic tree: Astasia granulata
Diagnosis:
- body variable from club-shaped, cylindrical to carrot-shaped
- very active euglenoid movement
- a nipple-shaped protruberance at posterior end always visible
- length 30–48 µm (of elongated cell)
- 1 flagellum of body length
- eyespot absent
- paramylon bodies egg-shaped, sometimes money roll-shaped
- paramylon mainly in anterior end, sometimes small granules posterior
- body can twist along the longitudinal axis
- weak striation of pellicle
I have found Astasia granulata in the Simmelried in December 2006. This species can be recognized by a nipple-shaped protuberance at the posterior end visible during almost all stages of the strongly euglenoid movement (s. figs. 1a and 1b). The larger, ovoid paramylon granules are located in the anterior half of the body, while very small granules sometimes collect at the posterior end (s. fig. 1d). My specimen had an average length of 55 µm, what is slightly above the given range for the size. Otherwise, all characteristics are consistent with the description of this species.
Fig. 1 a-d: Astasia granulata. L = 50–60 µm. Different stages of the metabolic movement of a freely swimming specimen. Note the nipple-shaped posterior end (arrows), visible in almost all euglenoid stages of movement. In the posterior end a collection of small granues (PG) is visible. AG = anterior granules, F = flagellum. Obj. 60 X.