SUCKERS OF UTAH LAKE A. GAYLON COOK BIOCONSERVATION INTERNATIONAL 3306 N CANYON RD PROVO UT 84604-4548 Running Head: SUCKERS OF UTAH LAKE SUCKERS OF UTAH LAKE A. Gaylon Cook' ABSTRACT.— There has been much confusion about which suckers exist in Utah Lake, and even about the number of species present. Considerable misunderstanding has resulted from an incomplete exploration of the literature on catostomid morphology and taxonomy. Numerous descriptions of Utah Lake suckers have been recorded, but none has included all or close to all of the taxonomic characterizations that are now available. Herein, those descriptions are organized, collated, and discriminatingly analyzed so that different catostomids are defined and delimited as completely as possible. This paper establishes a basis for needed chemical taxonomic analyses such as DNA-DNA hybridization tests. Also, its detailed descriptions constitute a resource that can be used for such purposes as distinguishing taxa in periodic ichthyological surveys of Utah Lake or identifying suckers during recovery-plan activities on an endangered species. Key Words: catostomids, suckers, Utah Lake, taxonomy, systematics, endangered species, ichthyofauna Utah Lake, closely bordered by the city of Provo, is a 38,800-ha body of fresh water (Carter 1969: 2) in central Utah measuring 23.5 by 38.0 km (Radant and Sakaguchi 198 lb: derived from Fig. 1). This lake has a mean depth of 2.9 m and a maximal depth of 4.2 m (Radant and Sakaguchi 1981b: 2). It drains >6700 km2 of land (Carter 1969: 3-4) and formerly collected a flow of 740 million m3/yr (Arnold 1960: 11-17). Ignorance of the ichthyological literature and misperceptions about what it has established, have resulted in inaccurate nomenclatures and misinterpreted taxonomic relationships. Nescience about the phylogenetic relationships of Utah Lake catostomids is underscored by a dispute about the number of species present. Significantly, it is not known whether certain taxa constitute endemic species or subspecies that may be worthy of endangered status. The principal aim of this review is to establish a sound basis for defining and delimiting as precisely as possible the catostomids of Utah Lake. Species descriptions are compared in detail. It is hoped that this paper will lay the groundwork for further systematic investigations. Taxonomic studies employing DNA-DNA hybridization analyses, as well as those that might utilize biochemistry, 'Bioconservation International, Provo, Utah 84604-4548. GREAT BASIN NATURALIST 2 immunology, serology, protein sequencing, or comparative anatomy, need to be performed on Utah Lake suckers. Besides being quick, DNA hybridization offers the most precise quantitative comparisons (Sibley and Alquist 1990: 3). It is also anticipated that the characterizations that are presented here will assist ichthyologists in identifying Utah Lake catostomids. For example, descriptive data can be used by fishery biologists with the Utah Department of Natural Resources, Division of Wildlife Resources in their effort to identify endangered adult June Suckers (Chasmistes liorus), and distinguish them from 3 other catostomids during spawning-season sampling and reproductive facilitation in lower Provo River. Suckers are frequently misidentified by these biologists during reproductive surveys that are performed as a part of the June Sucker recovery plan (Charles W. Thompson, personal communication). The comparative temporal incidence of the catostomids of Utah Lake will be treated in a future paper. DESCRIPTIONS OF TAXA r Exceptional Sucker Catostomus generosus (exceptional low-mouth: Greek kato, low; stoma, mouth; Latin generosus, superior or exceptional) / Mountain Sucker Catostomus platyrhynchus (broad-snouted low-mouth: Latin platy, broad; Greek rhunkhos, snout or bill). Synonyms of these species are Acomus generosus (Girard 1857a, 1858: 221-222), Catostomus (Acomus) generosus (Girard 1857b: 174), Catostomus generosus (taken at Utah Lake) (Cope 1872), Minomus platyrhynchus, M. jarrovii, and C. ? generosus (all 3 collected about Provo, Utah) (Cope 1876), and Pantosteus platyrhynchus and P. jarrovii (Cope and Yarrow 1876: 673-675). Neither C. generosus nor the 1.1-kg C. ? generosus was described. To be able to confirm that they resemble A. generosus more than M. platyrhynchus or M. jarrovii, sound examples of the 2 generosus forms must persist, allowing their comparison with descriptions of the other forms, and any remaining intact exemplars of A. generosus and M. platyrhynchus (apparently no examples of M. jarrovii persist; see below). After comparing multiple specimens of each form, Jordan (1878a, b: 183-184) deemed Pantosteus (= Acomus = Catostomus) generosus equal to P. jarrovii, but the remarkably slender (allegedly due to flabbiness) P. platyrhynchus a separate species. Jordan (1878b) reported that P. generosus occurred in the "Rio Grande, Colorado Basin," and the "Great Basin of Utah". There was SUCKERS OF UTAH LAKE 3 actually no record of this species in Colorado. However, Cope and Yarrow (1876) had recorded collections of "P. jarrovii", a synonym of P. generosus, at 5 New Mexico localities. Perhaps, Jordan (1878b) considered the "Costilla, N. Mex" site, which existed on the New Mexico side of its border with Colorado, to be in the Colorado Basin. It is situated in San Luis Valley which lies principally in Colorado, and to an appreciable extent, in its Costilla County. Jordan (1878b) stated (see also Jordan and Gilbert [1882: 123]) that P. generosus and P. platyrhynchus were "very similar" but added, "...at present I consider (them) distinct." Later, Jordan (1886) proclaimed, "The type of Catostotnus generosus seems to me unquestionably identical with the type of" P. platyrhynchus and "with P. jarrovii". "The peculiarities of P. platyrhynchus seem to be due to its shriveled condition." Actually, 3 specimens (apparently syntypes) of A. generosus (Girard 1858) and several syntypes of M. platyrhynchus (Cope 1876) had been collected. Jordan (1887b: 805) lumped all 3 forms within P. generosus. Jordan (1891) and Jordan and Evermann (1896a: 170-171) regarded Cope's (1876) M. jarrovii and M. platyrhynchus as synonyms of A. generosus (Girard 1857a,b, 1858) but Cope and Yarrow's (1876: 674-675) P. jarrovii from New Mexico as a synonym of Catostomus plebeius which had been taken at Mimbres River near the border of USA and Mexico (Baird and Girard 1856). Jordan (1887a) and Jordan and Evermann (1896b: 238, 1902: 45-46) also did not consider platyrhynchus or jarrovii to be full species. Jordan and Evermann (1896a: 170) gave an inaccurate and incomplete synopsis of "P. generosus". Snyder (1916) placed generosus in the genus Notolepidomyzon with plebeius and 2 other forms, and surmised that jarrovii, whose "cotypes" were missing, was a synonym of generosus because it was squatter than platyrhynchus, to which he synonymized Pantosteus jordani from the upper Missouri River Basin (Evermann 1894). Believing that Pantosteus (= Acomus) generosus might equal Catostomus plebeius, Snyder (1922) speculated that the unit of Captain J. W. Gunnison and Lieutenant E. G. Beckwith, who were searching for a potential railroad route to the Pacific Ocean, took the former from the Rio Grande Basin of southern Colorado. Jordan et al. (1930: 104) assigned generosus and plebeius to the genus Notolepidomyzon, and platyrhynchus to Pantosteus, placing a question mark in front of the name of its synonym M. jarrovii from Provo, Utah, because "the type" (actually there were 2 syntypes) of GREAT BASIN NATURALIST 4 M. jarrovii (Cope 1876) had been lost. The synonymization of jarrovii with platyrhynchus was in error on the basis of previous examinations of specimens which indicated that jarrovii equaled generosus (see above). Based on the geographic ranges in Moore's (1968: 101) species accounts, his Catostonws platyrhynchus included generosus and jarrovii (see also Robins et al. [1991]). In an article rife with inaccuracies (e.g., the claim that specimens of Gila elegans and Algansea obesa were of unknown origin when in actuality, G. elegans had been collected at 5 different known sites including Grand River, Utah, and A. obesa had been taken in Humboldt River [Baird and Girard 1854a, Girard 1857a, b: 183, 205, 1858: 239, 286-287]), Snyder (1922; "do" in his table means "ditto") indicated that 4 or 5 of the 6 piscine species that had been taken in 1853 or 1854 at Cottonwood Creek, "an affluent of the great Salt Lake of Utah" (Girard 1857a, b: 174, 185-186, 197, 199, 1858: 21-22, 221-222, 243-244, 267, 271-272), were actually from the Mississippi River Basin. One of those 6 taxa was A. generosus. Apparently, Snyder's (1922) skepticism about the origin of fishes that had been taken in "Cottonwood Creek, Utah" was triggered by Jordan and Evermann's (1896a: 273) comment that the recorded collection site of Cyprinella gunnisoni (Girard 1857a, b: 197, 1858: 267-268; equals Leuciscus (= Notropis) bubalinus [Baird and Girard 1854b] based on Jordan's [1886] statement that "The types of C. gunnisoni seem to be the young of N. bubalinus"; see also Jordan and Evermann [1896a: 273], Jordan et al. [1930: 130]) must be in error because Notropis spp. do not occur in Utah. Snyder (1922) reasoned that if any specimens (e.g., those of Notropis spp.) which were reported to have been taken from Cottonwood Creek, Utah were not actually collected there, none of them were. In accordance with the publication and comments of Snyder (1922), a colleague and former student of Jordan's at Stanford University, Jordan et al. (1930: 130-131), without a sound evidential basis, proclaimed acquisitions of C. gunnisoni from "Cottonwood Creek of the Rio Grande, Colo.", C. ludibunda (Girard 1857a, b: 199, 1858: 271-272; = Notropis ludibundus of Jordan and Evermann [1896a: 273] and contrary to priority, N. stramineus of Robins et al. [1991: 77]; see also Jordan et al. [1930: 130]) from a "locality now known to be Cottonwood Creek, Colo.", and C. lugubris (Girard 1857a,b, 1858; likely = N. macrostomus; see Jordan and Gilbert [1882: 177], Jordan and Evermann [1896a: 274], Jordan et al.