Larva a large semi-thummi type; ventral tubules about equal length. Mentum with broad centre tooth , side teeth relatively well separated (type I or II); 4th laterals reduced at least to level of 5th laterals (type II).
Cytology
: 4 pairs of chromosomes with the thummi arm combination AB, CD, EF, G.
Arm G generally unpaired, sometimes cloudlike, sometimes with clear
bands and heterochromatin
cap in the area of the nucleolus. Nucleolus in arm F,
which may be heterozygous in males for one (in
region 3-4) or two (other in region 1) heterochromatic
bands. This polymorphism may be seen in all males
(Waskesiu) or only in a small number (Lake Amisk, Baptist
lake). Most common pattern in all arms as in C.
anthracinus. Polymorphism in arms A, B, C, D and
F.
Arm h'antA1: 1a-2c, 10-12a, 13ba, 4a-c, 2g-d, 9-4d,
2h-3, 12cb, 13c-19
i.e. as plumosus2
Arm h'antA2: 1-2c, 10-12a, 13ba, 3f-2h, 4d-9e, 2d-g, 4c-a, 3g-i, 12cb, 13c-19
Arm n'antA3: 1-2c, 9a-e, 2d-g,
4c-a, 13ab, 12a-10, 8a-4d, 2h-3, 12cb, 13c-19
Arm h'antB1: not mapped.
Arm h'antB2: Simple inversion near distal end.
Arm h'antC1: 1-6b, 11c-8, 15-11d, 6gh, 17a-16, 7d-a,
6f-c, 17b-22
Arm n'antC3: small inversion of region about 17a-6c.
Arm h'antD1: 1-3g, 14g-16, 8c-7g, 5d-7f, 18d-17,
8d-10a, 13a-11, 14f-13b, 10b-e, 4-5c, 18e-24
Arm h'antD3: 1-3g, 14g-16, 8c-7g, 18a-d, 7f-5d,
17f-a, 8d-10a, 13a-11, 14f-13b, 10b-e, 4-5c, 18e-24
Arm h'antE1: 1 - 3e, 5 - 10b, 4 - 3f, 10 - 13
i.e as
cingulatus,
tardus
and sp. 3b.
Arm h'antF1: 1 - 8e, 9c - 23
Arm n'antF3: 1 - 8e, 9c-e, 14 -
10, 15 - 23
Click here to see the polytene chromosomes.
Found: Alberta -
Lake Amisk.
Manitoba - Baptist Lake.
Saskatchewan - Lake Waskesiu, Prince Albert
National Park.
Wisconsin - ¿Pleasant
Lake, Walworth Co. (W. Hilsenhoff).
Occurs at depth of 10 m or greater.
Morphology described by Rempel (1936) as C. hyperboreus. However Townes 1945 considered the adult was C. anthracinus Zett., to which the karyotype shows relationship such that Shobanov, Shilova and Belyanina (1996) and Kiknadze, Wuelker, Istomina and Andreeva (2005) have also considered it to be a synonym of C. anthracinus. This may well be correct, but there are some aspects that still suggest that it may be at least a separate subspecies: The heterochromatin on arm F and the sequences A3, C3 and F3 have so far only been found in certain Canadian samples, and the location of the MD has not been determined in any typical C. anthracinus populations. Karyotype pictured by Rempel et al. (1962) and in more detail by Kiknadze et al. (2005). This was Species 19 of Wülker.