\, I DRAFT EXECUTIVE ST]MMARY OF THE RECOVERY PLAN FOR TRE WOI]NDFIN ATID VIRGIN RIVER ROI'NDTAIL CHI'B Current Status: The woundfin and roundtail chub are listed as endangered. One population of these species are known from the Virgin River in Utah, Arizona and Nevada. Historically, the woundfin was collected in the Salt River near Tempe' Arizona; at the mouth of the Gila River near Yuma, Arizona; in the colorado River near Yuma, Arizona; in the Virgin River in Nevada, Arizona, and Utah and in LaVerkin Creek, a tributary to the Virgin River in Utah (Gilbert and Scofield 1898; Snyder 1915; Miller and Hubbs I960; Cross I975). The Virgin River roundtail chub has been collected from the Virgin River in Utah, Arizona and Nevada and from the Moapa River, a tributary to the Virgin River in Nevada. Habitat Requirernents and Limitins Factors: Woundfin are most often collected in run and quiet water habitats with sand substrates. Roundtail chubs are most often collected in deep run or pools associated instream cover. Alteration of flow regimes, decreasedwat.er quality and introduction of exotic species are the principal threats. Recovery Obiectives: Delisting Recovery Criteria: The woundfin and roundtail chub current listing of endangered will be recommended for threatened status when: (l) present Virgin River habitat- essential to survival of all life stages are assured; (2) when present marginal Virgin River habitat is upgraded to maintain all life stages; and (3) when an DRAFT additional population is established in a separate stream within historic range in which adequate habitat for all life stages of woundfin are assured. Delisting can be accomplished when a third self-sustaining population is established and adequate habitat for all life stages of that woundfin population are assured. Roundtail chub can be delisted when items I and 2 above are met. Actions Needed: t. Monitor existing and experimental populations. 2. Eliminate red shiners from the Vi-rgin River system above the Mesquite Divers ion. 3. Survey suitable habitat for additional populations of woundfin. 4. Establish two additional self-sustaining woundfin populations. 5. Conduct research on the biology of woundfin and roundtail chubs. 5. Conduct research on the potential for habitat improvements within the Virgin River and Moapa River for roundtail chub populations. 7. Conduct research on optimal flow regimes for maintaining self-sustaining and viable woundfin and roundtail chub populations within the Virgin and Moapa Rivers. DRAFT Costs: ($ 1000's) Year lleed I Need 2 Need 3 Need 4 Need 5 Need6 NeedT Total 1990 199 I L992 1993 1994 r995 1996 1997 1998 1999 2000 Total Cost of Reeovery Date of Recovery: Delisting should be iniriared in 2000. DRAFT TABLE OF CONTENTS INTRODUCTION WOTTNDFIN Taxonomic Status 6 Description. 6 ., Historical Distribution . Present Distribution 8 Life History/Ecology 9 Habitat l0 Food Habits l1 Reproductive Biology t2 Movement L4 VIRGIN RIVER ROUNDTAIL CHUB L4 Taxonomic Status I4 Description . T4 Historical Distribution . 14 Present Distribution l4 Life History/Ecology l5 Habitat t5 Food Habits l6 Reproductive Biology l6 ASSOCIATED SPECIES L7 HABITAT ALTEMTIONS l8 CHANGES IN ABI]NDANCE L9 LIMITING FACTORS 20 REASONS FOR LISTING 2T CONSERVATION MEASURES 2I STRATEGY FOR RECOVERY 24 RECOVERY 26 OBJECTIVE AND CRITERIA 26 NARRATIVE OUTLINE FOR RECOVERY ACTIONS ADDRESSING THREATS 27 NARRATIVE 29 LITEMTURE CITED 48 IMPLEMENTATION SCHEDI]LE 5l DRAFT INTRODUCTION WOIJNDFIN Taxouomic Status The woundfin is considered the most highly specialized species in the cyprinid tribe Plagopterini, subfamily Leuciscinae (Mi1ler and Hubbs f960). This unique tribe is composed of three genera, two ofwhich, Meda and Plagopterus, are monotypic' while the third, Lepidomeda, is composed of four species, one ofwhich contains two subspecies. The present taxonomic ranking of the group was initiated by Hubbs (1955), and is generally accepred. The uniqueness of this compact group of fishes has always impressed ichthyologists. Cope (L874) erected a ful1 subfarnily, the Plagopterinae, for the genera, and this was widely followed (Jordan and Gilbert 1883; Jordan and Evermann 1896). Jordan et al. (1930) even erected a separate family, the Medidae, for the group, an action followed only by Tanner (f936). The entire taxon is endemic to the lower basin of the Colorado River and its ancestral tributary, the White River. Description The woundfin, Plagopterus arsentissimus, is a streamlined silvery minnow with a flat head and a conspicuous, sharp dorsal spine, from which its conunon name was derived. The type specimen \r/as described by Cope in L874 from a collection apparently made in Washington County, Utah (Miller and Hubbs 1960). The woundfin is the most silvery of all American minnows (Miller and Hubbs 1960), reflecting blue in bright sunlight. The only breeding color noted has been a DRAFT ltash of light-yellow at the bases of the pectoral and pelvic fins. The species rarely achieves a standard length of more than 75 millj-meters (nrn). The head and belly of the woundfin are flattened, and the overall aspect of the fish is one of an anteriorly-depressed, streamlined torpedo. This body shape is characteristic of fish inhabiting swift, shallow, sand-bottomed, streans. Other adaptations to this type of habitat include expansive, falcate fins' barbels on the lips, reduced eyes, and extensive sensory buds, presumably chemoreceptorsr on the lower part of the head (the gular region in Plaeopterus) (Snyder 19f5), and along the leadingpectoral fin-rays (Moore 1950; Branson L963, 1966; Cross 1967). Woundfin are essentially scaleless, with the exception of small plates of bone situated in the leathery skin, especially near the nape. Adaptive features unique to the woundfin include a modification of the two anterior fin-rays of the dorsal fin into enlarged, elongated, and solidified spinose rays, the second of which fits into a groove in the first. Alsor the branched pelvic rays are thickened and spine tike on the basal half to three fourths of each ray. A further specialization in Plaeopterus is a spine like development near the base of the first few pectoral fin-rays. Eistorical Distribution 0n the basis of early records, the original range ofwoundfin extended from near the junction of the Salt and Verde Rivers at Tempe, Arizona, to the mouth of the GiIa River at Yuma (Gilbert and Scofield 1989); likely in the mainstream Colorado River near Yuma ("Fort Yumar'Jordan and Everman 1896; see also Meek DRAFT l9O4 and Follettr I961) thence upstream to the Virgin River in Nevada, Arizona, Utah and into LaVerkin Creek, a tributary to the Virgin River in Utah (Gilbert and Scofield 1898, Snyder I915, Miller and Hubbs 1960, Cross L975). However, from biological considerations alone, there is reason to believe that woundfin occurred further upstream on the Verde, Sa1t, and Gila rivers. As detailed by Miller and Hubbs (1960), the stated type locality "san Luis Valleyr Western Colorado (Cope and Yarrow 1875)r" was an obvious error, many of which rtrere cormnitted by collectors associated vrith the Wheeler Survey in 1871 to 1874. Miller and Hubbs also rejected as erroneous locality data the records from the "Colorado Chiquito River, Arizona" (Bohlke 1953) on the basis of no other indications that the fish ever inhabited that stream. The Wheeler expedition maintained a base at Toquerville, Washington County, Utah in L872, on LaVerkin Creek (I.Iheeler 1889), from where they worked on the Virgin River canyon and traveled to St. George. It seems likely that the type series of P. argentissimus was taken from the mainstream Virgin River (Mi11er and Hubbs 1960). Present Distribution Woundfin range from LaVerkin Springs on the mainstream of the Virgin River and the lower portion of LaVerkin Creek in Utah, downstream to the Riverside Diversion, Nevada. Collections of woundfin below the Riverside Diversion however, have been rare since tne late I97o' s (unpublished data, Virgin River Fishes Data Base). A single spec imen was taken from the middle Moapa River, Clark County, Nevada, in the late 1960's (Deacon and Bradley 1972). The Moapa River was formerly a tributary to the Virgin River, but both streams now flow 7 DRAFT into Lake Mead. The species has been transplanted into five localities in attempts to establish populations. In one locality, the Hassayampa River in Arizonar reproduction occurred in the sunmer of L972 but a flow in September of 1972 evidently destroyed the entire population (Minckley, pers. cornm. L977). In March, 1972, woundfin were also placed in the Salt River, Arizona, but none have been taken from their since. In Sycamore Creek, Agua Fria drainage, Arizona, a few specimens stocked in spring L972, survived the severe flooding of. I97?-3, and two individuals collected in late August, L973 were gravid. However none have been collected in Sycamore Creek since 1973. The fourth locality, the Paria River' along the Arizona-Utah border, was stocked several times between 1969 and L972. No woundfin were found during surveys in May, L974 and May, L975 (unpub. data, Arizona Game and Fish Stocking Records). The fifth locality, at the Dexter National Fish Hatchery, was established in 1988 to assist in research to develop rearing protocols. Life History/Ecoloey Hickman (f987b) cornpiled an annotated bibliography for the woundfin which surnmarizes most of the available published papers and government reports on this species. Principal taxonomic works are contained in Cope (187), La Rivers (L962)' Miller and Hubbs (f960), and Uyeno and Miller (1973). Distribution and status ofwoundfin are contained in Cross (1975, 1978, 1985), Hickman (1987), and Hardy et al. (f989). Life History, reproductive biology, and ecology can be found in Deacon (r977a,1977b, 1980), Deacon and Hardy (1980,1984), Deacon et a1 l9??, Greger and Deacon (1982,1986) and Heckman er al. 1986. DRAFT HabLtat Woundfin adults and juveniles are most often collected from runs and quiet lraters adjacent to riffles.