Genus Clydonella Sawyer, 1975
Diagnosis: Characters of the genus are intermediate between Vannella and Platyamoeba. Locomotive form with anterior hyaline region occupying 2/3 of the cell length. Hyaloplasm with faint lateral folds as ripples over anterior region. Locomotive form ovoid, usually 10 to 40 µm. No posterior uroid. Floating form with radiate, sometimes irregularly twisted pseudopodia; in some, radiating pseudopodia bent or extended in multiples of 2. Nucleus distinct with central nucleolus. Cytoplasm containing few vesicles. No cytoplasmic crystals or cysts. Fine structure of cell coat unknown.
Ecology: All 5 species marine.
C. vivax Schaeffer 1926
C. rosenfieldi Sawyer 1975
C. sindermanni Sawyer 1975
C. wardi Sawyer 1975
C. vivax, from Bovee and Sawyer, 1979
C. sawyeri Kudryavtsev and Volkova, 2018
Clydonella sawyeri Kudryavtsev and Volkova, 2018
Diagnosis. Locomotive forms 6.9-16.6 μm (average 10.6 μm) long, 5.9-20 μm (average 13.8 μm) broad, length:breadth ratio 0.49-1.28 (average 0.79) (n=107); in majority of cells breadth is greater than length. Rounded, oval or arc-shaped during locomotion, frequently with concave posterior margin, seldom with extended, triangular posterior end (that mostly occurs when changing the direction of movement). Floating form irregularly rounded, without pseudopodia. Ovoid vesicular nucleus 2.6-5.3 μm in diameter (average 3.7 μm) with large central nucleolus 1.6-2.9 μm in diameter (average 2.2 μm) (n=78). Glycocalyx consisting of fibrous basal layer, vertical pentagonal glycostyles ca. 100 nm in length, and simple filaments about 200 nm long.
Type locality: littoral zone of Seldyanaya Bay, Chupa Inlet (Kandalaksha Bay, The White Sea, North-Western Russia; 66.3384387N, 33,618127E), upper layer of mud and sand, salinity 22‰;
Reference: Kudryavtsev, A., Volkova, E., 2018. Clydonella sawyeri n.sp.(Amoebozoa, Vannellida): Morphological and molecular study and a redeﬁnition of the genus Clydonella Sawyer, 1975. European Journal of Protistology https://doi.org/10.1016/j.ejop.2018.01.008