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Home , Apache trout, Gila trout, Mexican golden trout

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J tap APACHE

My first exposure to what later proved to be , caused considerable consternation. This occurred in the late 1950's while conducting graduate research on the native trout of the Great Basin (mainly the native to the Lahontan and Bonneville basins of Nevada and Utah). I had borrowed all of the preserved specimens available in museums to examine in to characterize the subspecies described from the Lahontan and Bonneville basins. These diagnoses would allow me to recognize these subspecies if they still existed. Both the Lahontan subspecies henshawi and the Bonneville subspecies Utah were generally regarded to be extinct as pure populations at the time, but the problem was that if these subspecies still existed, how could they be verified since no valid diagnosis of the subspecies had ever been made.

My study was progressing nicely as I compiled the diagnostic traits of the two subspecies when I received three specimens from the U.S. National Museum labeled, "Panguitch Lake, Utah" (a lake in Bonneville basin). These specimens were collected in 1873 and were entirely distinct from any form of cutthroat trout known to me. The specimens were only about five to eight inches in length but their deep bodies, long fins, spotting patterns, and other internal characters such„ as the number of vertebrae were very different from any other trout with which I was familiar. I pondered the question in my MS. thesis; How could a trout so distinctively different from the Bonneville cutthroat have existed in the Bonneville basin and not previously recognized?

When I became aware that mix-ups of specimens and locality records of collections made by geological surveys and railroad surveys in the nineteenth century were a common occurrence, a bit of further investigation revealed that these three specimens (U.S. National Museum number 15999) were actually collected from the White Mountains of (from the ) tin gcribed by the zoologists B. D. Cope and H.C. Yarrow in 1875 as a variety of the cutthroat trout, " pleuritiQus." Cope and Yarrow most likely considered the peculiar trout they encountered in the White Mountains of Arizona as a variety of the Colorado River cutthroat trout because all of the rivers there drain to the Col6rado.River. They were not aware that the natural distribution of cutthroat trout in the Colorado basin did not extend to the •- the San Juan River of Utah, Colorado, and New is the,southem limit of plettriticus.

The early settlers in the region drained by the headwaters of the Little Colorado and Salt Rivers of eastern Arizona were familiar with the Apache trout which they commonly called "yellow belly" trout in reference to its coloration. Until the 195etVhowever, little was known of the Apache trout except that it had become very rare. It has beeit'estimated that the original distribution of Apache trout consisted of about 600 miles of streams, mainly at elevations between 6,000 and 9,000 feet. Before reintroductions occurred, pure populations of Apache trout existed in about 30 miles of a few small headwater streams.

In 1950, R. R. Miller of the University of Michigan, described the of the upper Gila River basin of New Mexico as a new , Salmo (now Oncorhynchui) gilāe,. In this 1950 publication, Miller mentioned the native trout of the White Mountains of Arizona which he regarded as a form of the Gila trout. Subsequent studies comparing Gila trout and Apache trout found several distinctions between them and in 1972, Miller formally described the Apache trout as a new species, S4Imo (now Oncorhynshus) apache.

The Apache trout is distinguished by its deep body, long fins, and light yellow coloration on the ventral part of the body. The sides of the body typically have yellowish- brownish-olive colors with purplish tints. The dorsal, anal, and pelvic fins have pronounced cream to yellow-orange tips. Black pigment on the iris of the eye anterior and posterior to the pupil gives a mask-like appearance to the eye. The spotting pattern of Apache trout with relatively large, rounded spots sparsely distributed over the sides of the body is similar to that of some interior subspecies of cutthroat trout. Apache trout also have a pale yellowish "cutthroat" mark. Looks can be misleading however; the Gila and Apache trout are most closely related to each other, and in turn, both are more closely related to than to cutthroat trout The cutthroat-like characters of Apache trout are primitive traits retained from an ancient common ancestor to both rainbow and cutthroat trout. In recent years modern techniques of genetic analysis have been used to demonstrate degrees of relationships. On a scale of to 10, with 1 being most close genetic relationships and 10 the most distant, the relationship between Gila and Apache trout would be in the range of 1 -2; between both Gila and Apache trout grouped together on one hand and rainbow trout on the other, the relationship measure would be about 3 - 4, and between Gila and Apache and cutthroat trout, about 9 -10. Because of the close relationship between the Gila and Apache trout, I classify them as two subspecies of a single species, Oncorhynchns Lone ear. and Q. g. apache.

The origins of Gila and Apache trout, in my assessment of the evolution of western North American trout, can be traced to a common ancestor which moved from the into the Gila River basin probably during a cold glacial period of the mid- Pleistocene (perhaps around a million years ago). Subsequently, the ancestral form became separated and differentiated into two groups, one in the northern part of the basin ( segment of Gila basin a-- Apache trout) and one in the upper main Gila basin (Gila trout). Warmer and drier climatic periods produced the present landscapes with cactus, sagebrush, and mesquite at lower elevations, progressing through pinion-juniper stands to the alpine forest at the highest elevations. The trout that radiated from the Gulf of California include the (spring 1988 Trout), and other rainbow-like trout of mountain tributaries to the Gull, besides the Gila and Apache trout, During warmer climatic periods, these trout persisted in isolated islands of high elevation refugia along with other southerly distributed pockets of cold-adapted alpine flora and fauna -- an assemblage of glacial relicts.

Because of their relatively close relationship to rainbow trout and because neither Gila trout nor Apache trout can coexist with rainbow trout without hybridizing and loss of identity, a logical argument could be made that both Gila and Apache trout should be classified as subspecies of rainbow trout. The Gila and Aache trout do have a unique complement of chromosomes (their karyotype). Both species have fewer chromosomes than any form of rainbow or cutthroat trout (56 vs, 58-68) and their chromosomes have a higher number of "arms" (106 vs. 104 - they have relatively more V-shaped than 1-shaped SCtLT, I.AZARUS, FRENCH, ZWZLLINGER & 3MOCK One Arizona Center Eleventh Floor 400 East Van Buren Phoenix, Arizona 85004 (602) 252-5100

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-3 O ) 92 Oepartnient of Fishery and Wildlife Biology L Fort Collins, Colorado 80523 6!eL (303) 491-5020 FAX (303) 491-509j

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No matter how Gila and Apache trout are classified, both are rare and worth saving but they require active intervention to preserve the remnant populations from extinction. Although some of the decline can be attributed to degradation of habitat, the major cause leading to placement of both Gila and Apache trout on the list (and protection under the Endangered Species Act has been the stocking of non-native brown, brook, and rainbow trout. and replace the native trout by competitive interactions. Rainbow trout hybridize with Gila and Apache trout and the offspring are fertile so that no reproductive barriers exist which can prevent the native trout from being modified or "absorbed" into introduced populations of rainbow trout.

The life history and "niche" characteristics of Gila and Apache trout broadly overlap those of other trout species so that coexistence by partitioning of resources doesn't work very well, especially in relatively small streams with limited habitat diversity. Like rainbow and cutthroat trout, the Apache trout is a spring spawner. Spawning is initiated by rising water temperatures (spawning begins at about 45° F) and declining flows. In different years and at different elevations spawning may occur from April into June. In small, cold headwater streams, Apache trout may be only 5-6 inches at three years of age when first spawning typically occurs. They feed opportunistically mainly on aquatic and terrestrial (as would other trout species in the same habitat), Apache trout readily take artificial (too readily for their own good if brown trout are present). In a stream on the Fort Apache Indian Reservation, electrofishing revealed that brown trout greatly outnumbered the Apache trout, but Apache trout were overwhelmingly dominant in the catch of fishers in this same stream.

The story of saving the Apache trout from the brink of extinction and subsequent restoration efforts is interesting and instructive. In the 1940's long before the Apache trout was officially recognized as a distinct entity (beore it was officially described and named), the White Mountain Apache tribe realized that the native yellow belly trout which once inhabited most of the waters on the reservation, had become very rare. As a first step to prevent extinction, a few headwater streams that still contained Apache trout were closed to angling by the tribe.

In 1964, a management plan was developed to restore the native trout on the reservation by chemical treatments of some streams to eliminate non-native trout and restore Apache trout. Also lakes were constructed where Apache trout could be stocked and attractive sport fisheries could be established. In 1975 an Apache trout recovery team was established, consisting of representatives of state and federal agencies and tribal members. Also in 1975 the status of the Apache trout under the Endangered Species Act was changed from endangered to threatened. This was an important change because a threatened status allows for regulated angling, Apache trout stocked in Christmas Tree Lake and Hurricane Lake grew to five pounds or more and these lakes were opened to a limited entry fishery (limited to 20 anglers per day per lake) for an additional fee and special regulations (flies and lures only, two trout bag limit, 14 inch minimum size). A world record Apache trout of 5 lb. 3 oz. was caught in 1991 and I expect new world records to be forthcoming.

The Apache trout recovery team began reint_oductions and restoration projects on U.S. Forest Service lands and steady progress has been made toward the establishment of 30 self-sustaining populations and eventual removal from the endangered species list. The most ambitious restoration program is being carried out by the U. S. Fish and Wildlife Service at the Alchesay-Williams Creek National Fish Hatchery. A brood stock of Apache trout has been established with a goal of annually producing about half million Apache trout, about half of them of catchable size. The hatchery-reared Apache trout will replace rainbow trout for stocking in waters of the Apache reservation which support intensive angling.

I wrote an article on Gila trout in the summer 1985 issue of Trout and I'll conclude this article with a brief resume of what has happened to Gila trout since then. Restoration efforts were progressing nicely according to the recovery plan and the status of the Gila trout was proposed to be changed from endangered to threatened in 1989. In the summer of 1989, however, a series of catastrophic natural events occurred in the upper Gila River basin -- an extended drought and forest fires followed by floods devastated the populations of Gila trout in their small sanctuary streams. This setback delayed the change in status and led to a new restoration strategthat could better cope with catastrophes. When we revisit the Gila and Apache trout at s me future time, I hope to be able to report good news on all fronts to the effect that these rare aquatic gems are flourishing and secure in their sanctuaries.

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