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
Astasia granulata
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.