GREAT LAKES COREGONIDS 



359 



GEOGRAPHIC DISTRIBUTION 



In Table 18 are assembled all my data on the occurrence of the chub in Lake 

 Huron. In Figure 5 these data are shown platted on the chart of the lake. 



Lake Huron proper. — There are 33 records made by me for Lake Huron. Except- 

 ing records 7 and 9, these were made from boats that fished nets expressly for chubs 

 and show the chub to range throughout the deeper American waters of the lake. 

 Aside from the fact that conditions are similar on the Canadian side of the boundary 

 line (from which it may be safely concluded that the species ranges in the Canadian 

 waters also) there is evidence derived from the comparison of the records of the 

 Southampton and Duck Islands boats, which fish in these waters, and those of Alpena 

 tugs (see p. 346) that indicate that the chub actually is taken abundantly in this area. 



North Channel. — No chubs have been seen from this region. Though the fisher- 

 men report Leucichthys off Gore Bay Light and off Meldrum Bay in 20 to 28 fathoms, 

 there is nothing in the description of these fish to indicate that they belong to this 

 species. On the contrary, in view of the large size of the fish reported and of the 

 shallow water in which they are taken, it seems safe to conclude that they are not 

 chubs. 



Georgian Bay. — Records 34 to 39 establish the occurrence of the chub in Geor- 

 gian Bay in summer and fall at depths corresponding to those at which it occurs in 

 Lake Huron. There is no reason to believe that it does not range throughout Geor- 

 gian Bay at similar depths at these seasons. From these data it appears that the 

 chub ranges throughout Lake Huron and Georgian Bay, but that none occur in the 

 North Channel. 



BATHYMETRIC DISTRIBUTION 



The records just reviewed deal mainly with the occurrence of chubs in the 2% 

 and 3 inch chub nets set at 35 to 100 fathoms. In less than 35 fathoms no chub 

 nets are set, so that the only sources from which evidence can be derived of the 

 occurrence of the chub at depths less than 35 fathoms are (1) the 43^-inch trout and 

 whitefish nets, (2) the four nets of 224-inch mesh that were set under my direction 

 with the 43^-inch nets, and (3) the l^-inch nets. (See p. 373.) 



1. The l^/i-inch trout and whitefish nets. — Record 7 shows a single specimen 

 taken on September 7, 1917, in 16 to 20 fathoms. This fish was too small to be 

 gilled in the nets. 



2. The 2%-inch nets set with the trout and whitefish gangs. — The nets lifted with 

 the 4j^-inch nets on September 17, 1917, in 15 fathoms, on September 19, 1917, in 

 30 fathoms, September 26, 1917, in 17 fathoms, and November 2, 1917, in 15 fathoms, 

 to determine whether the chub occurred in greater numbers than was shown by the 

 captures in the 4^-inch nets themselves brought in no chubs. The net of the 19th 

 brought in 9 longjaws and 6 short-jawed chubs. 



3. The lYi-inch bait nets. — From the lj^-inch bait nets at 30 fathoms only one 

 specimen was taken (record 9). Other lifts of these nets at a similar depth at Che- 

 boygan, Mich., on October 15, 1919, at Alpena, Mich., on September 16, 1919, and 

 at Harbor Beach, Mich., on December 9, 1917, and on March 15, 1919, revealed no 

 examples'of this species. 



94995—29 5 



