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<br />(' <br /> <br />~ <br /> <br />. <br /> <br />this river did not provide a suitable habitat for <br />the bony tail (W. L. Minckley, who has also stud- <br />ied the channel, concurs--pers. comm. 1976). <br />Study of Sitgreaves' report and map shows that his <br />last station in the basin of the Little Colorado <br />River (No. 13) was at Grand Falls. We thus assume <br />that this is the correct type locality for Gila <br />elegans and G. robusta (of which the third species <br />taken, G. gracilis, is a synonym). Incidentally, <br />the genus Gila was named for the river of that <br />name on the mistaken idea that the Little Colorado <br />River was tributary to Salt River of the Gila <br />River basin. <br /> <br />The perpetuation and management of robusta, <br />elegans, and cypha depends on the maintenance of <br />large sections of unspoiled, natural, main-channel <br />habitat. Dams threaten these species primarily by <br />destroying the swift-water habitat above the ob- <br />struction and drastically decreasing the tempera- <br />ture and turbidity below. Introduced exotic com- <br />petitors and predators (on young) are a threat, <br />especially in these modified areas. The most im- <br />portant current need is research on the habitat, <br />food, reproduction, recruitment, and hydrodynamics <br />and energetics of these forms of Gila, both for <br />the purpose of sound management and for the reason <br />that such information is one of the valuable bene- <br />fits that man can derive from these unique species. <br /> <br />Key to species of Gila in the Main-channel Habitat <br />of the Upper Colorado River Basin* <br /> <br />la. No nuchal hump, frontals nearly straight <br />(Figures 8,10 above), dorsal and anal rays usually <br />9, distance from anal origin (base of first ray) <br />to caudal base (bases of rays, internally) much <br />less than distance from anal origin to opercle <br /> <br />. . . . . . . . . . . . . . . robusta. <br /> <br />lb. Nuchal hump present in specimens over 150 mm <br />(Figures 6,9), frontals concave above eyes in <br />lateral profile (Figures 6,9,10 middle and below), <br />dorsal rays 9 or 10, anal rays 10 or 11, distance <br />from anal origin to caudal base about equal to or <br />greater than distance from anal origin to opercle <br /> <br />. . . . . . . . . . . . .. ..... 2. <br /> <br />2a. Nuchal hump abrupt (Figure 6), dorsal rays <br />usually 9, anal rays usually 10, in young less <br />than 150 mm the eye diameter less than 2/3 caudal <br />peduncle depth, snout overhangs upper lip (Figure <br />10 middle). . . . . . . . . . . . . cypha. <br /> <br />2b. Nuchal hump not abrupt (Figure 9), dorsal <br />rays usually 10, anal rays 10 or 11, in young less <br />than 150 mm the eye diameter greater than 2/3 <br />caudal peduncle depth, snout not overhanging <br />upper lip (Figure 10 below) . . . . . . elegans. <br /> <br />*Supplemental characters in Tables 1-3 aid <br />identification, especially for difficult speci- <br />mens and possible hybrids. Hybrids tend to have <br />several characteristics distinctive of each parent <br />and several intermediate. Specimens may be sent <br />to The University of Michigan Museum of Zoology <br />for identification. <br /> <br />LITERATURE CITED <br /> <br />BAIRD, S. F., and CHARLES GIRARD. 1853. Descrip- <br />tions of some new fishes from the River Zuni. <br />Proc. Acad. Nat. Sci. Phila. 6:368-369. <br />BAIRD, S. F., and CHARLES GIRARD. 1854. Fishes, <br />pp. 148-152, pIs. 1-3. In, Sitgreaves, Capt. <br />L. Report of an expedition down the Zuni and <br />Colorado rivers. U.S. Senate, 33rd Cong., 1st <br />Sess., Exec. Doc., Washington. <br />DRYER, I. 1965. Grand Falls of the Little Colo- <br />rado. Nat. Parks Mag. 39(212) :10-12. <br /> <br />623 <br /> <br />....- <br /> <br />ESCHMEYER, W. N., and S. G. POSS. 1977. Review <br />of the scorpionfish genus Maxillicosta (Pisces: <br />Scorpaenidae), with a description of three new <br />species from the Australian-New Zealand region. <br />Bull. Mar. ScL 26 (4) :433-449. <br />GIRARD, C. 1858. Fishes. In: General report <br />upon the zoology of the several Pacific rail- <br />road routes. u.S. Pac. R.R. Expd. and Surv. <br />10(4) :i-xiv, 1-400. <br />HOLDEN, P. B., and C. B. STALNAKER. 1970. Sys- <br />tematic studies of the cyprinid genus Gila, in <br />the upper Colorado River basin. Copeia 1970 <br />(3) :409-420. <br />HOLDEN, P. B., and C. B. STALNAKER. 1975. Dis- <br />tribution and abundance of mainstream fishes <br />of the middle and upper Colorado River basins, <br />1967-1973. Trans. Amer. Fish. Soc. 104(2): <br />217-231. <br />KRAMER, R. H. 1967. Introduction, pp. 1-9. In: <br />Green River fishes and invertebrates. Spec. <br />Repot., U.S. Bur. Sport Fish. and Wildlife, <br />Utah Coop. Fish. Unit, Logan, Utah. <br />MILLER, R. R. 1945. A new cyprinid fish from <br />southern Arizona, and Sonora, Mexico, with <br />the description of a new subgenus of Gila and a <br />review of related species. Copeia 1945(2) :104- <br />1l0. <br />MILLER, R. R. 1963a. Distribution, variation, <br />and ecology of Lepidomeda vittata, a rare <br />cyprinid endemic to eastern Arizona. Copeia <br />1963 (1) :1-5. <br />MILLER, R. R. 1963b. Is our native underwater <br />life worth saving? Nat. Parks Mag. 3~(188): <br />4-9. <br />RINNE, JOHN N. 1976. Cyprinid fishes of the <br />genus Gila from the lower Colorado River basin. <br />Wassman J. BioI. 34(1) :65-107. <br />SITGREAVES, CAPT. L. 1854. Report of an expe- <br />dition down the Zuni and Colorado rivers. <br />U. S. Senate, 33rd Cong., 1st Sess., Exec. <br />Doc., Washington, 198 pp. <br />STROUD, R. H. 1963. Green River humpbacks. <br />Sport Fish. Inst. Bull. l4l:7~ <br />VANICEK, C. D. 1967. Ecological studies of <br />native Green River fishes below Flaming Gorge <br />Dam, 1964-1966. Ph.D. Thesis, Utah State <br />Univ. Issued as Spec. Rept., U.S. Bur. Sport <br />Fish. and Wildlife, Utah Coop. Fish. Unit, <br />Logan, 124 pp. <br />VANICEK, C. D., and R. H. KRAMER. 1969. Life <br />history of the Colorado squawfish, Ptycho- <br />cheilus lucius, and the Colorado Chub, Gila <br />robusta, in the Green River in Dinosaur <br />National Monument, 1964-1966. Trans. Amer. <br />Fish. Soc. 98 (2) :193-208. <br />VANICEK, C. D., R. H. KRAMER, and D. R. FRANKLIN. <br />1970. Distribution of Green River fishes in <br />Utah and Colorado following closure of Flaming <br />Gorge Dam. Southwest. Nat. 14(3) :297-315. <br />