Phacus elegans Pochmann 1942
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Simmelried
Phylogenetic tree: Phacus elegans
Diagnosis:
- longitudinally obvoid in outline, slightly asymmetric
- length 127–147 µm, width 38–40 µm
- anterior “lips” overlapping
- one „lip“ protrudes over the other
- posterior end narrowed to a long spine, 40–50 µm
- pellicle longitudinally striated
- red eyespot prominent
- chloroplasts disc shaped
- paramylon bodies small
- flagellum shorter than cell
I regularly find Phacus elegans in the Simmelried. I have not yet been able to find this species in my other sampling sites.
Phacus elegans has a somewhat asymmetrical body shape. The right half protrudes slightly over the left half. This can be seen in the right lip, which protrudes slightly. On the other hand, the left half is slightly shifted backwards and merges into the spine with a stronger curvature. The right half, on the other hand, merges into the spine with a slight, flat curve.
At 100-120 µm, the specimens in my population were somewhat smaller than indicated by Huber-Pestalozzi (1955). Differentiation from the similar species Phacus lismorensis is not easy. Phacus elegans appears somewhat plumper and the right lip is not as head-shaped as in Phacus lismorensis. Otherwise the two species are very similar.
More images and information on Phacus elegans: Michael Plewka-Freshwater life-Phacus elegans
Fig. 1 a-c: Phacus elegans. L = 110 µm. A slightly squashed specimen from dorsal. Obj. 60 X.
Fig. 2 a-c: Phacus elegans. L = 118 µm. A second slightly squashed specimen from dorsal. CV = contractile vacuole, RE = reservoir. Obj. 60 X.
Fig. 3 a-b: Phacus elegans. L = 115 µm. A squashed specimen from dorsal. Chl = disc-shaped chloroplasts, ES = exespot, Nu = nucleus. Obj. 100 X.