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BULLETIN OF THE BUREAU OF FISHERIES 



collection, similarly separated according to size. From these tables it may be seen 

 that the only differences recognizable in the two classes are differences of proportion. 

 It appears that the head and eye are proportionally but slightly larger in the smaller 

 specimens, while the snout is shorter and the body depth is less, of course. 



The smallest specimens that were collected at Sheboygan, Wis., on September 

 28, 1920 (144 to 150 millimeters), showed developing sex glands and probably would 

 spawn at the succeeding spawning season. Occasional specimens under 170 milli- 

 meters have been found to be immature, however. 



COMPARISONS 67 



Reighardi is most like zenithicus in appearance. A discussion of the differences 

 between the two forms is given on page 389. Reighardi is compared with johannx 

 and alpense on pages 351 and 365. 



Reighardi differs from nigripinnis in its more elliptical body shape as seen from 

 the side, its shorter and more included mandible, paler body and fins, wider body, 

 fewer gill rakers on the first branchial arch and lateral-line scales, and much shorter 

 paired fins. Certain of these characters are compared below: 



Gill rakers on the first branchial arch: 



reighardi, (30) 34-38 (43) , with 3 per cent more than 40. 



nigripinnis, (41) 46-50 (52). 

 Lateral-line scales: 



reighardi, (66) 72-81 (96), with 26 per cent more than 79. 



nigripinnis, (74) 80-87 (89), with 84 per cent more than 79. 

 Pv/P: 



reighardi, (1.7) 2-2.5 (2.8), with 97 per cent more than 1.8. 

 nigripinnis, (1.5) 1.6-1.8 (2.2), with 18 per cent more than 1.8. 

 Av/V: 



reighardi, (1.2) 1.4-1.7 (1.9), with 42 per cent more than 1.5. 

 nigripinnis, 1.2-1.5 (1.6), with 8 per cent more than 1.5. 



As reighardi spawns in the spring and nigripinnis in the winter, the state of 

 ripeness of the sex products also may serve as a distinguishing character. 



Reighardi is distinguishable from Tciyi by the body shape, which is subterete 

 in the former and sub fusiform in the latter; by the length of the mandible, which 

 in reighardi is always included in the upper jaw while in Jciyi it is equal to or usually 

 longer than the upper jaw; and by the smaller, less sharply triangular head and shorter 

 paired fins. Comparative figures for certain of these characters follow: 

 L/H: 



reighardi, (3.9) 4.1-4.5 (4.8), with 85 per cent more than 4.1. 

 kiyi, (3.7) 3.8-4.1 (4.3), with 8 per cent more than 4.1. 

 Pv/P: 



reighardi, (1.7) 2-2.5 (2.8), with 96 per cent more than 1.9. 

 kiyi, (1.1) 1.4—1.7 (2.1), with 4 per cent more than 1.9. 

 Av/V: 



reighardi, (1.2) 1.4-1.7 (1.9), with 91 per cent more than 1.3. 

 kiyi, (0.96) 1-1.3 (1.4), with 2 per cent more than 1.3. 



As reighardi spawns in spring and Tciyi in fall, females usually are distinguish- 

 able by the condition of the ovaries. 



87 Figures given in this section for proportions are based on specimens 200 millimeters or more in length. Counts are given for 

 specimens of all sizes. 



