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BULLETIN OF THE BUREAU OF FISHERIES 



eye, and is much less pigmented throughout. The mandible, maxillary, and pre- 

 maxillaries, especially, usually are immaculate or nearly so in johannse and con- 

 spicuously pigmented in the other. As johannse spawns in August or September 

 and reighardi in May or June, the state of ripeness of the sex glands may be helpful 

 often in separating the species. A comparison of certain characters of the two 

 species follows: 



Gill rakers on the first branchial arch: 



johannse (26) 27-32 (36), with 7 per cent more than 33. 



reighardi, (30) 34-38 (43) , with 90 per cent more than 33. 

 Pv/P: 



johannse, (1.5) 1.6-1.8 (2.1), with 8 per cent more than 1.9. 

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

 Av/V: 



johannse, (1.1) 1.2-1.5 (1.6), with 7 per cent more than 1.5. 

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



The chub is separable at once from the blackfin by its less numerous gill 

 rakers on the first branchial arch, which in the former are not more than 36 and in 

 the latter not less than 41, and by the absence or sparseness of pigmentation on the 

 premaxillaries, maxillary, mandible, and the ventral fins, which in nigripinnis are 

 usually densely pigmented. The chub has a longer snout, also, a narrower and more 

 attenuated head, a smaller eye, and a much paler body and fins. Females often 

 may be distinguished by the state of development of the ovaries. The chub spawns 

 in late August and early September and the blackfin in late December and early 

 January. 



Only small johannse are comparable with Tciyi, as Tciyi attains less size than most 

 of the species of the genus. Specimens of the two species may be separated by the 

 number of gill rakers on the first branchial arch, which in johannse are never more than 

 36 and in Tciyi are not known to be less than 34; and by the paler mandible, pre- 

 maxillaries, and maxillary, which in johannse are immaculate, or, in the case of the 

 first two, but sparingly pigmented and in Tciyi abundantly pigmented; and by the 

 character of the body, which in Tciyi is conspicuously thin and frail. Johannse also 

 has a smaller eye and somewhat shorter paired fins. Females usually can be dis- 

 tinguished by the state of development of the ova, as johannse spawns in August and 

 September and Tciyi probably in October. 



Hoyi also does not regularly grow as large as johannse, and the two species are 

 at once distinguishable by the number of gill rakers on the first branchial arch, which 

 in johannse are not more than 36 and rarely more than 33, and in hoyi not less than 

 37; by the body shape, which in johannse is rather ovate in side view and in hoyi 

 elliptical; by the pigmentation rarely present on the premaxillaries, mandible, and 

 maxillary of johannse and always present on those parts in the other; by the more 

 numerous lateral-line scales, which in johannse. number (74) 80-90 (95), with 95 per 

 cent more than 77, and in hoyi (60) 67-77 (84), with 7 per cent more than 77. The 

 snout in johannse is much longer, so that the head, viewed from the side, is more 

 attenuated. Johannse spawns in August and September and hoyi in March, so that 

 the state of development of the sex organs often is a criterion to separate the two 

 species. In hoyi the mandible is frailer and more hooked. 



