Hyalotheca dissiliens
Brébisson ex Ralfs 1848
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Simmelried, Ulmisried, Paradieswiesen
Phylogenetic tree: Hyalotheca dissilens
Diagnosis:
- cells subcylindrical, lateral margings slightly constriczed
- length 15–25 µm, width 20–30 µm
- cells with two rings of pores
- filaments of cells covered with thick mucilage sheath
- one chloroplast per cell with one pyrenoid
- nucleus central
The desmid alga Hyalotheca dissiliens is very common and sometimes occurs in masses. It then forms algal mats similar to Spirogyra. It is very easy to identify due to a typical constriction of the cell equator (s. fig. 3 a), which the similar species Hyalotheca mucosa lacks. In addition, the cell wall of Hyalotheca dissiliens has two rings of pores (s. fig. 3 b), which are sometimes hard to see. The cell filament is surrounded by a thick mucilage sheath, which has typical radial stripes.
Fig. 1 a-b: Hyalotheca dissiliens. L = 19 µm (of cells). Two focal planes of a filament of cells. Note the mucilage sheath (MS) with a thickness of about 18 µm. Obj. 40 X.
Fig. 2 a-b: Hyalotheca dissiliens. L = 19 µm (of cells). Two focal planes of the end of the filament as shown in fig. 1 a-b. The terminal cells are broadly rounded. Obj. 40 X.
Fig. 3 a-b: Hyalotheca dissiliens. L = 15 µm (of cells). Two focal planes of a filament of young, transparent cells. Note the central nucleus (Nu) in each cell and the cell wall with two rings of pores (PO). Chl = chloroplast, CO = constriction of the lateral margins. Obj. 60 X.
Fig. 4 a-b: Hyalotheca dissiliens. L = 19 µm (of cells). The slightly squashed filament as shown in fig. 1 a-b in detail. Obj. 100 X.