<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 />
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