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<br />TABLE 2. Native fishes of the Colorado River Basin, including their current federal legal status and historic distribution/location in
<br />the basin (Evermann and Rutter 1895; Ellis 1914; Beckman 1952; Koster 1957; Miller 1959, 1961, 1972; Sigler and Miller 1963;
<br />Miller and Lowe 1964; Rinne 1976; Bailey et aI. 1970; Baxter and Simon 1970; Rinne and Minckley 1970; Deacon and Bradley 1972;
<br />Minckley 1973, 1979; Holden and Stalnaker 1975; Cross 1976; Moyle 1976; Joseph et al. 1977; Behnke 1979; Deacon et al. 1979;
<br />Hubbard 1980; Lee et aI. 1980; Molles 1980; Robins et aI. 1980; Carothers and Minckley 1981; Parenti 1981; Behnke et aI. 1982;
<br />Tyus et aI. 1982; U. S. Department of the Interior 1982, 1983, 1985a-e, 1986a-e, 1987; Behnke and Benson 1983; Williams et aI.
<br />1985; Minckley et aI. 1986; Stanford and Ward 1986c; Johnson 1987). X - indicates species has occurred;? - indicates presence
<br />questionable; * - indicates endemic genera, species, or subspecies. cont'd
<br />
<br />Species
<br />
<br />Federal
<br />legal
<br />statusC
<br />
<br />Historic distribution by major river drainagea
<br />Upper basinb Lower basinb
<br />
<br />CO GR SJ
<br />
<br />Historic location
<br />
<br />CO VR LC BW GI
<br />
<br />N X X X headwaters of upper basin drainages, UT-
<br /> WY -CO
<br />N X headwaters of Upper Mainstem Colorado
<br /> River drainage, CO
<br /> 12 12 8 11 12 9 5 18
<br /> (9?) ( 12?) (19?)
<br />
<br />MUGILIDAE
<br />Striped mullet
<br />Mugil cephalus
<br />
<br />N
<br />
<br />ELEOTRIDAE
<br />Spotted sleeper
<br />Eleotris picta
<br />
<br />N
<br />
<br />COTTIDAE
<br />Mottled sculpin
<br />Cottus bairdi *punctulatus
<br />
<br />Paiute sculpin
<br />C. beldingi
<br />
<br />NUMBER OF SPECIES
<br />
<br />x
<br />
<br />X sporadic in lower section of Lower Main-
<br />stem Colorado river, AZ-CA-Mexico;
<br />mouth of Gila River, AZ
<br />
<br />?
<br />
<br />extreme lower section of Lower Mainstem
<br />Colorado River, AZ-CA-Mexico
<br />
<br />aMajor river drainages: CO - Mainstem Colorado, GR - Green, SJ - San Juan, VR - Virgin, LC - Little Colorado, BW - Bill
<br />Williams, GI - Gila.
<br />bDividing line at Lee Ferry, AZ.
<br />cFederallegal status under the 1973 Endangered Species Act as amended: T - threatened, E - endangered, P - proposed for listing,
<br />U - under review (candidate), N - no federal status (however, certain of these taxa are variously protected by one or more basin
<br />states) 0 - extinct.
<br />dlncluded here are populations referred by Rinne (1976) to Gila robusta grahami Girard; problematic fishes currently under study.
<br />eThis distinctive form may be worthy of subspecific rank, but remains under study.
<br />fThis taxon was raised to specific rank by Rinne (1976); an action followed by several western biologists (Rinne and Minckley 1970;
<br />M inckley 1973; Minckley et al. 1986).
<br />gMany distinctive forms of speckled dace occur in the Lower Colorado River Basin, especially as "big-river" forms in most major
<br />streams and also as isolated populations in headwaters and springs. Status of these may never be determined because of complexities
<br />of their variation.
<br />hThe Little Colorado sucker, proposed as an undescribed species related to flannelmouth sucker by Minckley (1973), is yet to be for-
<br />mally described.
<br />iMinckley (1973) provided reasoning for retaining Pantosteus as a valid genus (see Smith 1966 for the alternative view).
<br />jCertain Pantosteus of the Bill Williams and Virgin rivers are distinctive and may represent valid species. This is especially true for
<br />the Bill Williams River, where P. clarki typical of the Gila River drainage co-occur with another form (Minckley 1973).
<br />kAs with P. clarki, this highly available taxon may include a number of unrecognized species.
<br />IParenti (1981) demonstrated that the United States genera Crenichthys and Empetrichthys belong to the family Goodeidae, an other-
<br />wise live-bearer family of central Mexico.
<br />
<br />to conspecifics in adjacent river basins. Twenty species are
<br />known only from the lower basin and (excluding marine
<br />forms) were largely confined to small to medium-sized river
<br />channels. The Virgin and Gila river drainages represent
<br />centers of endemism. Only eight species were common to
<br />both the upper and lower basins. Of these, humpback chub,
<br />bony tail , Colorado squawfish, tlannelmouth sucker, and
<br />razorback sucker, the so-called "big river" fishes, were
<br />generally restricted to large, mainstream channels. Biology,
<br />ecology, and habitat requirements of the basin's native
<br />
<br />fishes have been reviewed in detail by Minckley (1973,
<br />1979), Deacon and Minckley (1974), Behnke et al. (1982),
<br />Behnke and Benson (1983), Stanford and Ward (1986c), and
<br />contributors to Spofford et al. (1980) and Miller et al.
<br />(1982a).
<br />Merriam's vegetation zones were employed in Grafs
<br />(1985) description of natural riparian vegetation. At upper
<br />elevations in the basin, riparian communities were domi-
<br />nated by willows. In lower (Transition, Upper Sonoran, and
<br />Lower Sonoran) zones, riparian vegetation was a complex
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