462 



BULLETIN OF THE BUREAU OF FISHERIES 



H/E: 



hoyi, (3.3) 3.6-3.8 (4.2), with 16 per cent more than 3.8. 

 johannse, (3.6) 4-4.2 (4.5), with 95 per cent more than 3.8. 

 alpense, (3.6) 3.8-4.1 (4.4), with 78 per cent more than 3.8. 

 zenithicus, (3.5) 3.7-4.1 (4.3), with 60 per cent more than 3.8. 



H/S: 



hoyi, (3.5) 3.7-3.8 (4.2), with 78 per cent more than 3.6. 

 johannse, (3.1) 3.3-3.5 (3.6). 



alpense, (3.3) 3.4-3.6 (3.9), with 23 per cent more than 3.6 

 zenithicus, (3.5) 3.7-4.1 (4.3), with 53 per cent more than 3.6. 



The ventrals in hoyi average shorter, possibly, than in nigripinnis and longer 

 than in alpense and zenithicus. 



Zenithicus spawns in late September and early October in Lake Huron, instead 

 of November, as in Lake Michigan. The size at which sex organs begin to mature 

 is less for hoyi than for any of the chubs, being about 110 millimeters, as compared 

 with 220 millimeters for nigripinnis, 165 millimeters for johannss, 160 millimeters 

 for alpense, and 139 millimeters for zenithicus. 



GEOGRAPHICAL DISTRIBUTION 



Lake Huron proper. — The records in Table 58 (see also fig. 5), with the exception 

 of Nos. 30, 34, and 35, are from my own observations and show that the bloater 

 occurs off Cheboygan and Harbor Beach, Mich., in 30 to 50 fathoms in the 2% an d 



inch gill nets; off Rogers, Mich., in 35 fathoms in the 2%-inch nets; and off 

 Alpena, Mich., in 14 to 100 fathoms in the 4^, 2%, and \y<i inch nets. Off Tober- 

 mory, Ontario, the fishermen also report that bloaters are extremely abundant in 

 June in the 43^-inch nets in 30 fathoms. As physical conditions apparently are no 

 different in other portions of the lake, it is likely that the bloater occurs throughout 

 the lake at depths of 14 to 100 fathoms. 



North Channel. — According to the statements of three fishermen, the bloater is 

 taken in the North Channel off Gore Bay Light in 20 to 25 fathoms. There is still 

 deeper water off Meldrum Bay, in which the bloater probably also is found. 



Georgian Bay. — On December 3, 1919, a lj^-inch net lifted from 15 fathoms in 

 Colpoy Bay (record 41) had a few bloaters. This is the only record for bloaters in 

 less than 50 fathoms for the bay, though in more than 50 fathoms they are taken in 

 the chub nets as in Lake Huron. There is then no reason to suppose that the bloater 

 does not occur thoughout the bay, as there are wide areas that are covered by about 

 30 fathoms of water. 



BATHYMETRIC DISTRIBUTION 



The bloater has no commercial value, and though large numbers often become 

 entangled by the jaws in the chub nets and in the trout and whitefish nets, they are 

 never brought to market. However, nets are set for them in American waters by the 

 hook fishermen, who use them as bait for the trout hooks. These nets are of lj^-inch 

 mesh and are set at about 30 fathoms throughout the fishing season, which for the 

 hook fishermen embraces virtually the entire calendar year with the exception of the 

 closed season for trout. 



1 . Data from the 1 Y^-inch bait nets. — On Lake Huron there were two ports 

 from which such nets were operated in 1917 — Alpena and Harbor Beach, Mich. 



