2 
BULLETIN OF THE BUREAU OF FISHERIES. 
Genus CRISTIVOMER Gill & Jordan. 
Cristivomer namaycush (Walbaum). Lake Trout; Great Lakes Trout; Mackinaw Trout; Togue; Longe; 
Namaycush; Siscowet. (PI. i.) 
The Great Lakes trout or Mackinaw trout occurs throughout the Great Lakes region, and in the 
lakes northwestward to the Yukon and the Arctic Sea. It is subject to many variations in color and 
in degree of plumpness, but we find no tangible differences on which the genus can be separated into 
species or subspecies. 
A notable variant is found in the siscowet ( Salm o siscowet Agassiz, Lake Superior, p. 333, 1850; 
Sahno siskawitz Agassiz in Herbert, “Frank Forester’s Fish and Fishing, p. 143, fig. on p. 144, 1849). 
This is a pale trout, excessively fat and with the skeleton feeble for its size, found in Lake Superior and 
in waters of 50 to 80 fathoms. It is never seen in shallow water. It differs in no technical respect from 
the ordinary lake trout, and it is connected with the latter by perfect intergradations known locally as 
half-breeds. The siscowet is taken in schools of the deep-water ciscoes, the bluefin ( Leuciclithys cyanop- 
terus), the cisco (L. supernas ) and the Lake Superior longjaw (L. zenithicus), themselves also soft-bodied 
and very fat. There is every reason to believe that the siscowet is an ordinary trout which has fed 
Fig. i. — Cristivomer namaycush sisco-wel. Siscowet. (Drawn from specimen 18 inches long, taken 
in Lake Superior off Marquette. Mich.) 
on these soft fat fishes and which has followed them into deep water. If so, it should not be regarded 
as a distinct species or subspecies. 
The siscowet is not badly flavored but too fat to be digestible, and it almost melts away in frying. 
Salted, it is more satisfactory, but there is little market for it. Sometimes the walls of the abdomen 
are over half an inch in thickness. 
Our text figure is taken from a small but very fat example of the typical siscowet taken in a 
School of bluefins in about 60 fathoms off Marquette. The colored plate is from a typical lake trout 
from Lake Michigan off Berrien County, Mich. 
Commercially the lake trout is of great importance. The catch in American waters for the Great 
Lakes in 1908, according to the Bureau of the Census, was as follows: 
State. 
Pounds. 
Value. 
1 29, 600 
6, 798, 000 
150, 400 
215, 000 
4, 710, 100 
$9, 640 
424, 080 
12. 55 ° 
n, 690 
34 °. 360 
12, 003 , 100 
798, 320 
