466 



BULLETIN OF THE BUREAU OF FISHERIES 



(These eggs undoubtedly were of zenithicus, as the bloaters were taken on the spawn- 

 ing grounds of this species.) One fish had eaten chiefly wheat, one had found bryo- 

 zoan statoblasts, and one contained a fish scale. 



It seems that the bloater will eat whatever occurs in his environment. It is 

 possible that the species feeds heavily on fish spawn. 



Leucichthys hoyi of Lake Superior 



The bloater of Lake Superior resembles the Michigan form in shape and general 

 appearance, but apparently it does not grow so large. The largest individual col- 

 lected measures 251 millimeters, but specimens over 200 millimeters were taken 

 rarely, though nets that would have gilled them were set in many situations in the 

 lake where their presence might have been expected. (See p. 382.) The systematic 

 characters of the two forms that can be expressed numerically are compared below: 



H/M: 



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

 Superior, (2.2) 2.3-2.5 (2.7). 

 Pv/P: 



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

 Superior, (1.4) 1.5-1.8 (2). 

 Av/V: 



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

 Superior, (0.9) 1.1-1.3 (1.6). 



Gill rakers on the first branchial arch: 



Michigan, (37) 41-44 (48) . 27 • 



Superior, (37) 41-44 (49) . 28 

 Lateral-line scales: 



Michigan, (60) 67-77 (84) .« 



Superior, (65) 69-78 (84) . 28 

 L/H: 



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

 Superior, (3.4) 3.7-4 (4.2). 

 H/E: 



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

 Superior, (3.2) 3.6-3.8 (4). 



These figures indicate that the Superior form has a proportionally larger head 

 and eye and longer paired fins and maxillary. There are also, on the average, 

 slightly fewer scale rows around the body at the various points of count. 



The color in life is about the same in the two forms except for minor details of 

 pigmentation. Superior specimens appear, on the average, to be a trifle more 

 pigmented. The anal fin, especially, is as often with some pigment as it is immaculate. 



No individuals were taken during the breeding season, so that nothing is known 

 about the development of pearl organs. Very probably they are developed as in 

 others of the Great Lakes Leucichthys and likely are not different from those described 

 for the typical form. 



VARIATIONS 



Racial variations. — Most of the specimens were collected from off the Apostle 

 Islands, and there is no sufficient number of specimens comparable in size taken 

 from any other locality for comparison. No material is available either to determine 

 whether there are any shallow-water and deep-water races occurring out of the same 

 port. In view of the fact that the transition to deep water is abrupt almost every- 



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

 other figures for Lake Michigan are given for 1,024 specimens between the limits of 82 and 199 millimeters, except the H/M values, 

 for which 108 specimens were measured. 



ss These figures for Lake Superior are based on an examination of 335 specimens ranging in length from 107 to 251 millimeters. 

 Figures dealing with proportions, excepting those for H/M (which are based on 61 specimens), are given for 291 specimens from 

 107 to 199 millimeters in length. 



