c J tap APACHE TROUT My first exposure to what later proved to be Apache trout, caused considerable consternation. This occurred in the late 1950's while conducting graduate research on the native trout of the Great Basin (mainly the cutthroat trout 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 order 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 fish 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 Arizona (from the White River) tin gcribed by the zoologists B. D. Cope and H.C. Yarrow in 1875 as a variety of the Colorado River cutthroat trout, "Salmo 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 Grand Canyon •- the San Juan River of Utah, Colorado, and New Mexico 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 Gila trout of the upper Gila River basin of New Mexico as a new species, 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 rainbow trout 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 Gulf of California 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 (Salt River 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 conifer forest at the highest elevations. The trout that radiated from the Gulf of California include the Mexican golden trout (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 FACSIMILE TRANSMISSION COVER SHEET DATE: October 6, 1902 File No. 02370.001 TU FROM: Caren R. Moehle TO: Dr. W. L. Minckley FACSIMILE NO.: 965-8087 We are sending you pages, including this Cover Sheet. Please telephone Karen at 02) 252-5100 if you have any problems Thank you! THE INFORMATION CONTAINED IN THIS FACSIMILE MESSAGE IS ATTORNEY PRIVILEGED AND CONFIDENTIAL INFORMATION INTENDED ONLY FOR THE USE OF THE INDIVIDUAL OR ENTITY NAMED ABOVE. 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COMMENTS: 34 e, , OCT 1 92 RECEivED -3 O ) 92 Oepartnient of Fishery and Wildlife Biology L Fort Collins, Colorado 80523 6!eL (303) 491-5020 FAX (303) 491-509j , e T L5 , A to_,,73 rtu p;cs A( l ofek rr1 " " T \r , JP C„) , - o r / :Y•olt r S c Ci ak C " II\at i4 A b r • 1 I 1-) Wf PUD 3'i H tcl-P c # 9 CS1 9 I el tivt y v eje 4 o "rhst. r_ --ry,,u Prwe, 0 4 4)1A40,1.) 6-1).-vvi rigs (\:f LAR (491f"-Pe T„,,A ‘I 63•01 4 1,1 r-t C.A.c s 9 c-t) 1 ,1 11. \ 0 +1, concert.„ exreffa - 0 1- 1\ \ r cu. 171- 0 6,b , I ill 71° 1 ...s- 4,-,,a42.-kvi .-e t vl VC k u 40-1) /,‘ 1 CY\ rs 1:) 7 ti ; 6., o r , tt, c v 1 1 ) cilvinc 1-0 refirv-4 3-rtio• Pi r IN`F,y l/ "? V'""1 e r-, 4 r2 / in ,.. tm o ri-`,,v.,) t ad" 0 M e ii 4 o 1 .1, s a fti f, Ai) 0 , c i e yi PO - 5 sr„,,,,k,y,„ . 4_, chromosomes). The unique karyotype could be used to argue that the Gila and Apache trout should be recognized as a separate species (with two subspecies). There are no universally accepted rules or definitions to determine the question: What is a species? In cases such as the "most correct" classification of Gila and Aache trout, the official decision is typically made by committee consensus -- not necessarily "right," but "official." 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.