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470 BULLETIN OF THE BUREAU OF FISHERIES 



Leucichthys hoyi of Lake Nipigon 



The bloater of Lake Nipigon has the same general form of body as the Lake 

 Michigan race, but there are average differences in the proportional lengths and in 

 the number of some of the multiple parts. It appears, however, that the species does 

 not commonly grow so large as in Lake Michigan. In virgin waters only 13 specimens 

 over 200 milhmeters in length were obtained, and the largest specimen measured 

 only 231 millimeters, whereas in Lake Michigan examples of over 200 milhmeters 

 are very common and the maximum recorded size is 265 millimeters. The most 

 conspicuous characters of the two forms are compared below: 



H/M: 



Michigan, (2.3) 2.5-2.6 (2.8). 

 Nipigon, (2.2) 2.3-2.4 (2.5). 

 Pv/P: 



Michigan, (1.3) 1.7-2 (2.5). 

 Nipigon, (1.2) 1.4-1.7 (1.9). 

 Av/V: 



Michigan, (1) 1.2-1.4 (1.6). 

 Nipigon, (1) 1.1-1.3 (1.5). 



Gill rakers on the first branchial arch: 



Michigan, (37) 41-44 (48) . 3 ° 



Nipigon, (40) 42-46 (48) . 81 

 Lateral-line scales: 



Michigan, (60) 67-77 (84) . 8 ° 



Nipigon, (66) 73-80 (85) . 31 

 L/H: 



Michigan, (3.6) 4-4.2 (4.5). 

 Nipigon, (3.6) 3.8-4 (4.2). 

 H/E: 



Michigan, (3.3) 3.7-4 (4.2). 

 Nipigon, (3.1) 3.6-3.8 (4). 



It appears, thus, that the Nipigon form tends to have a slightly higher average 

 number of gill rakers on the first branchial arch and of scales in the lateral line, and a 

 proportionally longer head, eye, maxillary, and paired fins. The number of dorsal 

 rays also tends to become greater. The usual range is not changed, but there are 

 more specimens that register in the upper limits. The scale rows around the body 

 average fewer, the branchiostegals more, the mandible longer, and the height of the 

 anal fin in proportion to its base length (AC) averages greater; that is, the rays are 

 longer. For some values for most of these characters, see the detailed comparison of 

 10 specimens from each lake given in Tables 57 and 63. 



The color in life was not recorded but probably is not different from that of the 

 Michigan form. Alcoholic specimens show, in general, less pigment than the typical 

 form. The distribution of the pigment on the body is about the same, but the pig- 

 ment dots on the dorsal surface usually are fewer and rather coarser, and the pectoral 

 and anal fins, as well as the ventrals, are usually immaculate. Even the dorsal and 

 caudal may be very pale but usually are smoky. The maxillary, which is always 

 pigmented in the Lake Michigan form, may be immaculate, also, but usually shows 

 more or less of pigment over its proximal half. 



No specimens were seen ready to spawn, so that it is not known to what extent 

 pearl organs are developed. The nuptial dress probably is no different from that 

 described for the Lake Michigan form. 



M These figures for Lake Michigan are based on an examination of 1,161 individuals from 82 to 265 millimeters in length. The 

 other figures are given for 1,024 specimens less than 200 millimeters long, except the H/M value, for which 108 specimens were 

 measured. 



" These figures for Lake Nipigon are based on an examination of 174 specimens ranging in length from 106 to 231 millimeters. 

 The other figures, except those for H/M, which are based on 82 specimens, are given for 158 specimens less than 200 millimeters long. 



