Hedriocystis brachypous
(De Saedeleer, 1930) Siemensma, 1981
Most likely ID: n.a.
Synonym: Monomastigocystis brachypous
Sampling location: Simmelried
Phylogenetic tree: Hedriocystis brachypous
Diagnosis:
- cell in a polygonal shell with short, hollow stalk
- shell with pores on conical elevations
- pseudopodia arise from pores
- pseudopodia granulated
- diameter of shell 13–21 µm
- spherical nucleus with central nucleolus
- one peripher contractile vacuole
So far I have only found Hedriocystis brachypous once in July 2003 in the Simmelried. I have no further records of this species.
Hedriocystis brachypous forms a polygonal shell on a short, hollow stalk. In my specimens I could also recognize a thin thread of cytoplasm connecting the cell with the base of the stalk (s. fig. 1 a). The shell consists of a transparent, organic material and has several hump-like elevations with pores. The pseudopodia, which are about twice as long as the shell, are extended through these pores. Only bacteria are phagocytized as food.
Hedriocystis brachypous can be distinguished from the similar species Hedriocystis pellucida by its short, hollow stalk.
More images and information on Hedriocystis brachypous: Ferry Siemensma-Microworld-Hedriocystis brachypous
Fig. 1 a-b: Hedriocystis brachypous. L = 18 µm. Two focal planes of a specimen attached to an algae filament. The specimen is connected via a thread of cytoplasm (arrow) with the base of the hollow stalk. Obj. 100 X.
Fig. 2 a-b: Hedriocystis brachypous. L = 17–19 µm. Two specimens attached to an algae filament. Nu = nucleus, St = hollow stalk. Obj. 100 X.