Larva a small to medium sized plumosus-type larva. Lateral tubules turn ventrally as described by Sasa (1978) for Japanese specimens. Ventral tubules well developed. Head generally brownish; gula and frontoclypeus darkened, and also some darkening along outside edge of frontoclypeus. Centre teeth of mentum relatively broad, with c2 teeth well separated and sharp (type II); lateral teeth sharp with 5th laterals slightly above the graduated level of the other lateral teeth. Sasa (1978) shows small notches near the tip of the center tooth, but these will only be seen if the mentum is not worn.
Cytology: 4 pairs of chromosomes with the pseudothummi-cytocomplex combination AE, BF, CD, G.
Centromeres strongly heterochromatic and constricted. Pairing may occur betwen the centromeres of different chromosomes. Arm G mostly paired, with BR near middle of arm and no nucleolus. Nucleolus developed in arm A. A fixed asymmetrical pericentric inversion occurs on chromosome CD, transferring the proximal bands of arm D into arm C, or alternatively it may be a duplication of the CD centromere region(Wülker, pers. comm.), equivalent to those reported for the AE and BF centromeres in some other pseudothummi-cytocomplex species such as C. dorsalis (Kiknadze et al. 2008). No polymorphism in studied North American or Japanese populations.
aceA1: 1a-i, 7 - 9, 2d - 3, 12 - 10, 2c - 1k, 6 - 4, 13 - 19 with large nucleolus in segment 15.
aceB1:
aceC1: 1 - 2, 13 - 14?, 10 - 8, 15, 11 - 12, 6b - 2, 16, 22 - 18, 6c - 7, D(see below) (Wülker, prelim).
Arm D1: 1 - 2, 10, 4 - 6b, 8, 18, 13 - 11, 3, 22? K 23a-g, 7 - 6c, 17 - 22? (Wülker, prelim).
Arm E1: 1 - 3e, 10b - 3f, 10c - 13 ie. as acidophilus, frommeri, whitseli, etc.
Arm F1: 1, 12p - 11, 2 - 6 14 - 12p, 16 - 17, 10 - 7, 18 - 23 (Wülker, prelim).
Click here for the polytene chromosomes.
Found: California -
Wyoming - Nymph Creek, Yellowstone National Park.
also found in Japan - Lake Katanuma, Honshu.
and in Europe - Reinbeck, Germany (Keyl 1962 - as C. crassimanus. synonymy by Wülker, unpubl.)
In acidic waters (pH3), and also elevated temperatures in North America.
Larva of Japanese specimens described by Sasa (1978) and Yamamoto (1986). Cytology of the European specimens was illustrated by Keyl and Keyl (1959), and banding pattern of arms A and E by Keyl (1962), as C. crassimanus.