Genus: Postoral kineties usually to left of oral poykinetids (Illustrated Guide, 1985). Left edge is more curved than right edge; cytopharynx with numerous strong fibrils; ectoplasm with numerous fusiform trichocysts; macronucleus oval; one to several micronulei (Kudo, 1966).
Species: 150-600 μm long; ventrally flattened; dark colored; buccal cavity close to anterior end (How to know the protozoa, 1979). Elongate 150-600 μm long; anterior is not wider than posterior; cytostome small with well defined pre- and postoral suture; a large macronucleus with three micronuclei; single contractile vacuole with 12 radiating canals; many trichocysts (Carey, 1992). Cell body 150-600 μm long (Kahl, 1930).
Google Image Search
RAPD tree of Frontonia (Tsukii, Jpn. J. Protozool., vol.36, 2002)
F. leucas
500-550 μm
Intact cells
Japan, 199?
F. leucas
928 x140 μm
trich. 9 x 1.5 μm
ingesting food
Ichikawa
Chiba, 2001
F. leucas
540-800 μm
Koaze river
Kawagoe
Saitama, 2002
F. leucas ?
Intact cells
Japan, 199?
F. leucas
stock, Nnm-1
280-312 μm
trich. 8 x 1 μm
Matsumoto
Nagano, 2001
DV images 
Nnm-1
348 x μm
4-9 Mic.
Matsumoto
Nagano, 2001
Cos-2
353 x μm
3-7 Mic.
Ichikawa
Chiba, 2001
Cos-1
391 x μm
3-4 Mic.
Ichikawa
Chiba, 2001
Gmt-6
369 x μm
2-4 Mic.
Tatebayashi
Gunmma, 2001
Hsf-4
μm
Sanda
Hyogo, 2001
SIR-24
μm
Iruma
Saitama,
Ckr-1
μm
0 Mic. ?
Misc.
F. leucas ?
F. marina ?
Intact cells
Japan, 199?
F. leucas ?
cell division
Japan, 199?
F. leucas ?
cyst formation?
Japan, 199?
F. leucas ?
excystment ?
Japan, 199?
Frontonia sp.
F. marina ?
Intact cells
Japan, 199?
Frontonia sp.
F. marina ?
Mac. and Mic.
Japan, 199?
Frontonia sp.
Mac.
Japan, 199?
Frontonia sp.
Mac. & Mic.
Japan, 2002
