Entosiphon sulcatum Stein, 1878
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Simmelried, Purren pond, Mainau pond, Bussenried, Bündtlisried, Ulmisried, Mühlhalden pond, Mühlweiher Litzelstetten
Phylogenetic tree: Entosiphon sulcatum
Diagnosis:
- body oval with 4–8 longitudinal grooves
- length 20–25 µm, width 10–15 µm
- trailing flagellum about twice body length
- leading flagellum about body length
- cytopharynx with a tube-shaped ingestion apparatus (siphon)
- siphon reaches almost the posterior end
- nucleus lateral, at about mid-body
- one lateral contractile vacuole in anterior third
Entosiphon sulcatum is one of the most common colorless, eugenid flagellates. It occurs in almost all of my sampling sites. The species is easily identifiable by the tubular siphon and the distinct longitudinal grooves of the pellicle. I find Entosiphon sulcatum particularly often in floating detritus flakes in old samples. Entosiphon sulcatum also likes to settle on the floating coverslip.
Fig. 1 a-b: Entosiphon sulcatum. L = 24 µm. Two focal planes of a slightly squashed specimen. Note the tube-shaped siphon (Si) and the longitudinal grooves (Lg) of the pellicle. CV = contractile vacuole, LF = leading flagellum, Nu = nucleus, TF = trailing flagellum. Obj. 100 X.
Fig. 2 a-b: Entosiphon sulcatum. L = 27 µm. Two focal planes of a second specimen. Note that the siphon (Si) is reaches almost down to the posterior end (arrow). LF = leading flagellum, Nu = nucleus. Obj. 100 X.
Fig. 3 a-c: Entosiphon sulcatum. L = 28 µm. Three focal planes a slightly squashed specimen in the process of cell division. Note the doubled siphons (Si 1, Si 2). The specimen appears pink due to ingested rhodobacteria (IR). LG = longitudinal grooves of the pellicle. Obj. 60 X.