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<br />
<br />Figure 16. Beaver pond on the East Fork of the Little
<br />Colorado River, at Phelps Cabin, Arizona. This type of
<br />aquatic habitat must have supported large numbers of
<br />native trouts in times past.
<br />
<br />Disappearance of beaver as a result of
<br />overtrapping may also have been a major factor in
<br />habitat degradation. Beaver ponds in the White
<br />Mountains of Arizona (Fig. 16) now support large
<br />numbers of Apache trout. None of these changes has
<br />been critically assessed, but higher summer water
<br />temperatures, changed nutrient relationships, and
<br />increased turbidity and sediment transport may all
<br />be predicted; none benefits native trout.
<br />Recovery efforts for native trout in the United
<br />States have had public and agency support because
<br />of their positive image as game and food fishes, their
<br />beauty, and the romanticism with which high
<br />mountains and their streams are viewed. The plans
<br />are basically to isolate and protect selected
<br />populations that represent the phenotypes (and
<br />presumably the genotypes) in wilderness or
<br />comparable remote areas, and use hatchery strains
<br />for restocking other streams within the native ranges.
<br />In this way, both species may be managed for their
<br />continued survival, as well as for use by man.
<br />However, the presence of non-native species will
<br />continue to be a problem, which may prove
<br />insurmountable. Future management should exclude
<br />non-native trouts from the ranges of native species.
<br />To my knowledge, no specific program has yet
<br />been developed for native trout conservation in
<br />Chihuahua and Sonora, other than (1) inclusion of
<br />natural populations in the National Parks at EI SaIto
<br />de Basaseachic, Sonora (Rio Mayo drainage), and
<br />San Pedro Martir in Baja California del Norte, and
<br />(2) general recognition of the value of the unique
<br />Mexican trouts in the Rio Fuerte headwaters to the
<br />south, and on Sierra San Pedro Martie.
<br />
<br />Other Species
<br />
<br />Only a few warmwater fishes ascend high enough
<br />to interact on a day-to-day basis with trouts in the
<br />United States. The speckled dace/pecesito moteado is an
<br />exception, since they commonly reproduce up to
<br />2100 m elevation. Spinedaces in the Little Colorado
<br />and Virgin rivers also occupy high-elevation habitat
<br />along with trouts at the upper limits of their ranges;
<br />their ecology is discussed below. Desert mountain-
<br />sucker/matalote del desierto also go into headwaters,
<br />but few are resident there.
<br />In Mexico, Leopold suckers/matalote del Bavispe
<br />(Fig. 17) seem characteristic of high-elevation trout
<br />waters, as is Rio Grande mountain-sucker/matalote del
<br />Rio Bravo (Fig. 18) in its limited distribution (one
<br />stream known) in the Rio Yaqui basin. Five other
<br />kinds (see below) reach the upper limit of altitudinal
<br />distributions somewhat below the extreme
<br />headwaters, but still occur broadly with native trout.
<br />In one example, a trout in the Rio Papigochic
<br />sub-basin of the Yaqui basin lives in a stream
<br />
<br />."'... '.'''''' .
<br />7o,_;i>:~" I;. ., /: 7
<br />
<br />, .
<br />. . ",- ~...
<br />
<br />,., ",. :'-':. ,:~',',i",'.:,"r , --:::"'~;;,;'i",:" ,.-rj::'-~.._
<br />
<br />. .'4',. ,~~ ",. ',<;'';\. to. ,'r,. ,," .." '. ~.> '. '.
<br />I~ ',,,1'., ~.}.,- ~'~._ ~~,...~ _~ _<_;~
<br />.... .1';...,...", ,.' ~", "".' ,
<br />"" '~. . .~ .-'0-
<br />I;M'" . .,~, .(~, .'."_.~
<br />..~ jill'.'. ,~,.~ ~. .' ....".,. I,
<br />~~', ~,,*",-;I..\~,.~.::.~ ..~., ",;-..-:I"r.,.\ .~"
<br />.' " ~~:. <A ..'....~;~., ~1:::t :.:~ .. ; ~"
<br />...."'~ ..",'L.....~,.~~, ,.:~. ''.I'~ ..".~. ,,_.
<br />.. .' -. -.", - "~ . (J. ".,. <;T~-! _ '~ "., , -:v. -~
<br />'~"., .' ":. ..1.u~ ,~;. .-IT ". . ....,.. '",',.
<br />· '. .. -~~"!'J-"-.( . ":'-',')' ,
<br />· !.. . elL.
<br />
<br />Figure 17. The Leopold sucker/matalote del Bavispe is listed
<br />as a species of special concern. The specimen illustrated is
<br />11.0 cm in total length, from Rio Negro, Chihuahua.
<br />
<br />
<br />Figure 18. Rio Grande mountain-sucker/matalote del Rio
<br />Bravo, 13.5 cm in total length, Rio de las Vacas, New
<br />Mexico. The red lateral band is characteristic coloration for
<br />a fish in breeding condition. This species remains locally
<br />common in much of the upper Rio Grande basin in the
<br />United States and Mexico, and in a number of independent
<br />drainages in the Sierra Madre Occidental of Mexico.
<br />
<br />10
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