482 



BULLETIN OF THE BUREAU OF FISHERIES 



segregate these individuals under the name prognathus. However, he found the rate 

 of growth of the long-jawed specimens to be like that of their associates. On October 

 25, 1920, I examined several hundred specimens from a lift of some thousands of 

 pounds of herring taken off Port Dover, Ontario (the source of Clemens's specimens), 

 and found them to be typical albus; so there seems to be no reason to believe that 

 any other Leucichthys, least of all the deep-water prognathus, occurs in Lake Erie. 

 The tendency of individuals of a shallow-water species living in deep water to acquire 

 a longer mandible is illustrated by L. hoyi, also. (See p. 460.) 



Size variations. — Only a few specimens are available for a comparison of changes 

 with growth. In Tables 8 to 11 are shown the relative proportions of large and small 

 specimens, and in Table 67, 10 specimens under 200 millimeters are compared exten- 

 sively with 3 groups of 10 each of specimens larger than 200 millimeters. Only between 

 the large and small individuals taken at the eastern end of the lake can comparisons 

 be drawn satisfactorily, as these presumably are related genetically. In the case of 

 these the data indicate (as was to be expected) that the head and eye are relatively 

 larger in the small individuals. The paired fins also appear to be 'longer and the 

 depth less. 



Specimens under 17 centimeters in length have been taken only in the eastern 

 waters and have been found to be sexually immature. Larger individuals usually 

 have been mature. In western waters no mature specimens have been seen smaller 

 than 23 centimeters. 



COMPARISONS 



Leucichthys artedi and Coregonus clupeajormis are the only coregonids known 

 from Lake Erie. The generic distinctions are quite evident, and the species are not 

 confusable. 



GEOGRAPHICAL DISTRIBUTION 



Herring occur in schools, and these formerly occurred not only out of every port 

 on the lake but in almost every situation in it. Almost since the beginning of fishing 

 operations the herring has been an important factor in the commercial fisheries, and 

 for many years it has been their mainstay, particularly in the eastern waters. In 

 the west, on the flat westward from Sandusky, the schools have been so depleted 

 that herring fishing has been virtually abandoned in this area for 25 years. The 

 middle grounds (that is, the 100-mile stretch between Point Pelee on the west and 

 Long Point on the east, which has a maximum depth of 14 fathoms) until about 1920 

 produced several million pounds of herring annually. Since 1925 the deep hole to 

 the east of Long Point also has been depleted, and the herring, once present in 

 supposedly inexhaustible quantities, is commercially near extinction. In Table 66 

 are given data for the specimens that I have collected. 



METHODS OF CAPTURE 



Gill nets are used most widely for taking the species. Until recently, nets of 

 meshes as small as 2% inches were allowed by some States on the ground that the 

 herring in the eastern waters were smaller than those elsewhere, but the legal net is 

 now everywhere of 3-inch mesh. The gill nets are commonly of exceptional depth 



