(DRAFT) - Taxonomy
                         Species SPRINGFISH, RAILROAD VALLEY
                                Species Id ESIS251026
                                   Date 14 MAR 96



TAXONOMY

NAME - SPRINGFISH, RAILROAD VALLEY OTHER COMMON NAMES - SPRINGFISH and RAILROAD VALLEY ELEMENT CODE - CATEGORY - Fish PHYLUM AND SUBPHYLUM - CHORDATA, CLASS AND SUBCLASS - OSTEICHTHYES, ORDER AND SUBORDER - ATHERINIFORMES, FAMILY AND SUBFAMILY - GOODEIDAE, GENUS AND SUBGENUS - CRENICHTHYS, SPECIES AND SSP - NEVADAE, SCIENTIFIC NAME - CRENICHTHYS NEVADAE AUTHORITY - TAXONOMY REFERENCES - COMMENTS ON TAXONOMY - Railroad Valley Springfish Crenichthys nevadae Hubbs, 1932 KINGDOM: Animal GROUP: Fish PHYLUM: Chordata CLASS: Osteichthyes ORDER: Atherinifomes FAMILY: Goodeidae Crenichthys nevadae was described by C.L. Hubbs in 1932 from two specimens collected by C.T. Brues during field investigations of hot springs at Duckwater, Nye County, Nevada (07). Individuals of this species are small, typically cyprinodont-appearing fishes, with protractile premaxillaries. Williams (15) recorded total lengths of individuals from Duckwater to vary from 13 to 72 mm, with an average of 34.5 mm. The dorsal and anal fins are located far back, and pelvic fins are absent. Jaw teeth are bicuspid and uniserial, and the pharyngeal teeth are conical. The head is large and heavy, flattened above the eye, and is contained about 3.1 times standard length (07). Hubbs (07) recognized Crenichthys as a close relative of Empetrichthys. No written description of coloration or markings was given by Hubbs except to mention that, in comparison with Empetrichthys, "coloration differences are also striking; C. nevadae is much less mottled, but has the lateral blotches much bolder". Taxonomy - 1 (DRAFT) - Taxonomy Species SPRINGFISH, RAILROAD VALLEY Species Id ESIS251026 Date 14 MAR 96 Hubbs (07) placed C. nevadae in the Family Cyprinodontidae, Order Cyprinodontes (=Cyprinodontiformes), along with Empetrichthys and other cyprinodont fishes (08,09). Nelson (11) placed the Cyprinodontidae in the Order Atheriniformes. However, Parenti (12) and Deacon and Williams (04) recently placed Crenichthys and Empetrichthys in the family Goodeidae, previously considered to occur only in west-central Mexico. The holotype specimen is a maturing female 44 mm long to caudal, and was collected by Dr. and Mrs. C.T. Brues in an isolated warm spring at Duckwater, Nye County, Nevada, on July 21, 1930; field number 58 (the specimen is housed in the Museum of Comparative Zoology of Harvard University, catalog number 32,948). The paratype is deposited (as Catalog Number 95,024) in the Museum of Zoology of the University of Michigan (07). An illustration of this species is located in Hubbs (07), and on file with the U.S. Fish and Wildlife Service (Office of Endangered Species - Washington, D.C.) biological files is a photo of Railroad Valley Springfish. Taxonomy - 2
                                  (DRAFT) - Status
                         Species SPRINGFISH, RAILROAD VALLEY
                                Species Id ESIS251026
                                   Date 14 MAR 96



STATUS

Coded Status T: Federal Threatened COMMENTS ON STATUS - U.S. STATUSES AND LAWS: The Railroad Valley springfish (Crenichthys nevadae) has been designated a Threatened species pursuant to the Endangered Species Act of 1973 (50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C. 1531-1540), as amended. The species has this status wherever found including the State of Nevada. Critical Habitat has been designated in Big Warm Spring and its outflow pools, streams, and marshes and a 50 foot riparian zone around the above areas in T13N, R56E, NE1/4 Sec. 31, SE1/4 Sec. 31, NW1/4 Sec. 32; and in Little Warm Spring and its outflow pools, streams, and marshes, and a 50 foot riparian zone around these areas in T12N, R56E, Sec. 5, of Nye County, Nevada (50 CFR 17.95(e)). Special rules concerning "take" for this species can be found in 50 CFR 17.44(n). This species is protected by the Lacey Act (P.L. 97-79, as amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import, export, transport, sell, receive, acquire, or purchase any wild animal (alive or dead including parts, products, eggs, or offspring): (1) in interstate or foreign commerce if taken, possessed, transported or sold in violation of any State law or regulation, or foreign law; or (2) if taken or possessed in violation of any U.S. law, treaty, or regulation or in violation of Indian tribal law. It is also unlawful to possess any wild animal (alive or dead including parts, products, eggs, and offspring) within the U.S. territorial or special maritime jurisdiction (as defined in 18 U.S.C. 7) that is taken, possessed, transported, or sold in violation of any State law or regulation, foreign law, or Indian tribal law. RESPONSIBLE FEDERAL AGENCIES: USFWS -Responsible for the management/recovery, listing, and law enforcement/protection of this species. BIA -Responsible for the law enforcement/protection of this species with applicable State and Federal laws on public lands under their control. Also responsible for management/recovery on Bureau of Indian Affairs lands. BLM -Responsible for the law enforcement/protection of this species with applicable State and Federal laws on public land under their control (43 CFR 4140). Also Status - 1 (DRAFT) - Status Species SPRINGFISH, RAILROAD VALLEY Species Id ESIS251026 Date 14 MAR 96 responsible for management/recovery on Bureau of Land Management lands. All Federal agencies have responsibility to ensure that any action authorized, funded, or carried out by that agency is not likely to jeopardize the continued existence of the species or result in the destruction or adverse modification of Critical Habitat (50 CFR 402), and to utilize their authorities to carry out programs for the conservation of the species. STATE STATUSES AND LAWS: STATE: Nevada DESIGNATED STATUS: Protected ADMINISTRATIVE AGENCY: Nevada Department of Wildlife STATE STATUTE: Nevada Admin. Code 503.015 to 503.080, Dec. 21, 1981; NV Admin. Code 503.584 to 503.589. INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS: The Railroad Valley springfish is listed as a "Vulnerable" species in the IUCN Red List of Threatened Wildlife (1986). ECONOMIC STATUSES: The species has no presently recognized economic value. 82/12/30:47 FR 58454/58460 - Notice of Review 83/06/14:48 FR 27273/27274 - Notice of Petitioning 84/04/17:49 FR 15109/15113 - Proposed Rule - Threatened w/ Crit. Hab. 84/07/31:49 FR 30554 - Notice of public hearing/comment period 86/03/31:51 FR 10857/10865 - Final Rule - Threatened w/ Crit. Habitat Status - 2
     

HABITAT ASSOCIATIONS

HABITAT - AQUATIC INLAND AQUATIC LAND USE - Cropland and Pasture Mixed Rangeland Nonforested Wetland NATIONAL WETLAND INVENTORY CODES NWI NWICLS NWIMOD NWISPEC Palustrine EM5 COMMENTS ON HABITAT ASSOCIATIONS - The Railroad Valley springfish occurs only in thermal springs and associated outflows and marshy areas in Railroad and Hot Creek Valleys, Nye County, Nevada, and in a small area of thermal springs and channels near Sodaville, Mineral County, Nevada (05). Several of these outflows have been modified and cleared for agricultural use (i.e. irrigation for pasture and hay fields). The surrounding habitat is a mixed range land. Big Warm Spring, located on the Duckwater Indian Reservation, has a discharge which varies between about 5,800 gallons per minute (gpm) and 7,300 gpm (10). The other six springs which contain native C. nevadae populations within Railroad Valley are much smaller, discharging from 200 to 600 gpm (10,14). Chimney Spring and a spring in Hot Creek Canyon, both of which contain transplanted populations of springfish, discharge about 100 and 360 gpm, respectively (10,15). Spring pool depth of Big Warm Spring is not precisely known, but is approximately 5 meters, and depth of Little Warm Spring is approximately 2 meters. All five springs at Lockes Ranch are from 0.5 to 1.5 meters deep. The spring pool at Big Warm Spring is circular and 24 meters in diameter, and that of Big Spring is 10 meters in diameter. Other spring pools are quite small, usually less than 1 meter in diameter. Outflows tend to be shallow and less than 1 meter wide, except for that of Big Warm Spring which is several meters wide (15). Substrate of the spring headpools is typically sand, gravel, or pebble (15), and some decaying organic matter. Portions of some outflows contain dense algal mats of Rivularia, a nitrogen-fixing blue-green algae (03). The spring pools and outflows typically have a narrow, but dense, riparian border consisting of Juncus and/or Typha. Distichlis (salt grass) is common in marshy areas adjacent to springs and outflows. Springs and outflows at Lockes Ranch contain varying amounts of duckweed (Lemna), pondweed (Potomgeton), Chara, Ceratophyllum, and Utrichularia (13). The following water temperatures have been recorded at the headsprings (in deg. C): Big Warm Spring (33.5), Little Warm Spring (31.0), North Spring (35.0), Hay Corral Spring (32.0 to 34.0), Reynolds Springs 1 & 2 (35.0), Big Spring (37.0), Chimney Spring (32.0 to 34.0), Sodaville Spring (38.3) (06,15,18,19). Springfish have been reported to occur down the spring outflows at Big Spring to a temperature of 18.3 deg. C (13). Studies by Willimas (15) showed the critical thermal maximum for C. nevadae to be 38.2 deg. C. Specific conductance in mmhos/cm ranges from approximately 760 at Chimney Spring; 660-690 at the Lockes Spring complex (06,15,19) to 535-587 at Duckwater (15,18). Conductivity (in mmhos/cm) at the Habitat Associations - 1 Sodaville Springs is much higher, approximately 1,600 - 1,900 (06). Habitat Associations - 2
                                (DRAFT) - Food Habits
                         Species SPRINGFISH, RAILROAD VALLEY
                                Species Id ESIS251026
                                   Date 14 MAR 96



FOOD HABITS

TROPHIC LEVEL - OMNIVORE LIFESTAGE FOOD FOOD PART General Detritus General Algae General Arthropods General Crustaceans General Molluscs Food Habits - 1
                         (DRAFT) - Environment Associations
                         Species SPRINGFISH, RAILROAD VALLEY
                                Species Id ESIS251026
                                   Date 14 MAR 96



ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult LIM = Limiting RA = Resting Adult J = Juvenile FA = Feeding Adult RJ = Resting Juvenile BA = Breeding Adult FJ = Feeding Juvenile P = Pupae L = Larvae E = Egg RL = Resting Larvae FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS G G Aquatic Features: Pool areas G Aquatic Features: Springs [flowing] G Environment Associations - 1
                               (DRAFT) - Life History
                         Species SPRINGFISH, RAILROAD VALLEY
                                Species Id ESIS251026
                                   Date 14 MAR 96



LIFE HISTORY

FOOD HABITS: Food habits of Crenichthys nevadae have been investigated only for the population in Big Spring at the Lockes Ranch site complex during the period March to September (03,15,17). The ratio of degestive tract length to standard length of C. nevadae is 1.3:1. This, along with a black peritoneum color, is an indication of omnivorous feeding habits (03,15). However, Williams (15) found C. nevadae to be primarily herbivorous during March to May. At that time, plant foods, mainly filamentous algae, comprised 51.4% and 32.7%, respectively. Ostracods were the most important animal food, comprising 13.2% of total intestinal volume. Filamentous algae (primarily blue-greens) occurred in 72.7% of the intestines examined (N=11). During summer months (June - August), C. nevadae in Big Spring switches to a primarily carnivorous diet. Deacon et al. (03) found that animal foods comprised 64, 88, 68, and 65 percent of total intestinal volume in June, July, August, and September, respectively. Gastropods (54%) and plant material (26%) were the most important foods in June, but ostracods became the most important food in July, August, and September, comprising 83% of intestinal volume in July. According to Williams and Williams (17), ostracods were the primary food of the Railroad Valley springfish during their study period June - September), occurring in 82% of the digestive tracts examined, and accounting for 41.2% of the mean digestive tract volume. Williams (15) found that animal foods comprised 74.3% of the intestinal volume during summer months, and that 46.4% of total intestinal volume was due to ostracods. These crustaceans were a preferred food and were highly selected for during summer months, as indicated by high electivity indices (15,16). Other foods consumed by C. nevadae in Big Spring included ephemeropteran nymphs, copepods, amphipods, odonate nymphs, Acarina (water mites), chironomid larvae, and detritis (15). Detritus occurred in 57.1% of the digestive tracts examined by Williams (15), and accounted for 13.9% of total intestinal volume. Negative electivity indices were computed by William (15) and Williams & Williams (17) for chironomids, amphipods, gastropods, damselfly nymphs, and copepods during summer months. Presence of fish scales in 14.3% (15) and 16% (17) of intestines examined was considered by both investigators to be due to incidental ingestion while feeding on benthic foods. Deacon et al. (03) reported that C. nevadae "would often dive into and pull vigorously on strands of algae, as if specifically in pursuit of selected prey items". Other observations indicated that springfish also fed on drift, although identity of such food items was not discerned. No other observations of feeding behavior in C. nevadae have been reorted. HOME RANGE/TERRITORY: No information has been presented to indicate that this species exhibits any territorial behavior in its natural habitat. Williams (15) reported aggressive behavior by springfish held in aquaria, and Life History - 1 (DRAFT) - Life History Species SPRINGFISH, RAILROAD VALLEY Species Id ESIS251026 Date 14 MAR 96 observed an instance where a "loosely bounded territory" was defended by a dominant male. PERIODICITY: No information is known concerning this aspect of the species' life history. MIGRATION PATTERNS: No information is known except for the suggestion by Deacon et al. (03) that individulas may move into warmer headwater areas in the winter. COVER/SHELTER REQUIREMENTS: Actual cover/shelter requirements are unstudied. The springs and marshes where the species occurs contain Juncus, Scirpus, and Typha stands and dense algal mats (03,15). REPRODUCTIVE SITE REQUIREMENTS: In Big Spring, Deacon et al. (03) found C. nevadae eggs primarily adhered to Utricularia (bladderwart) plants along the margins of Scirpus beds during all months of the year. Highest densities of eggs were found at the two most downstream transects in the study area along the margins of the channel where extensive Utricularia mats were developed in shallow areas. High water temperatures in the upstream areas of the Big Spring system preclude sprinfish reproduction (05). REPRODUCTIVE CHARACTERISTICS: Female C. nevadae from Big Warm Spring had greatest ovary development during summer, somwhat less during spring and fall, but was poorly developed in winter. Average number of ova per female during spring, summmer, and fall was 264.5, 224.8, and 210.5, respectively, but dropped to 53.8 per female during winter. Most females contained several classes of ova simultaneously, indicating that they spawned two or more times annually. Juveniles were abundant from June - October. Females from the Big Spring outflow (some distance below the headspring) had the greatest number of ova per individual in spring (185 ova). Ova per female were also well-developed during the fall (134 ova) and winter (139 ova), but were lowest in summer (99 ova). Larvae were present March to November (15). Females from the Big Spring outflow (water temperature 35 - 38 deg. C, near the headspring, exhibited extremely low ovary development during all seasons, attributable to high water temperatures, and no larval fish were present. Laboratory observations indicated reproductive activity was severely depressed at 35 deg. C and higher temperatures (15). PARENTAL CARE: No information is known concerning this aspect of the species' life history. POPULATION BIOLOGY: No quantitative population monitoring through time has been done Life History - 2 (DRAFT) - Life History Species SPRINGFISH, RAILROAD VALLEY Species Id ESIS251026 Date 14 MAR 96 for this species. All natural populations have been subjected to habitat alteration and/or loss and are presumed to have declined. The Big Warm Spring population no longer occurs in the headspring pool or in much of the outflow where previously collected and observed (05,15). Population biology parameters are for the most part unstudied. Williams (15) found male/female sex ratios of C. nevadae from Big Warm Spring to vary seasonally from near 1 male:1 female in spring/summer to 1 male:1.65 females in fall. At Big Spring, seasonal sex ratios varied from near 1 male:1 female in spring to 1 male:1.82 females (summer) and 1 male:1.92 females (fall). Primary factors limiting populations of C. nevadae are habitat modification and the introduction of predatory and competing species (05,15,16). SPECIES INTERRELATIONSHIPS: Predation by channel catfish (Ictalurus punctatus) and competition with guppies (Poecilia reticulata) have been cited as causes for C. nevadae population decline in Big Warm Spring (05, 15,16). OTHER LIFE HISTORY DESCRIPTORS: None. Life History - 3
                           (DRAFT) - Management Practices
                         Species SPRINGFISH, RAILROAD VALLEY
                                Species Id ESIS251026
                                   Date 14 MAR 96



MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE Beneficial Controlling water levels Beneficial Land Acquisition Beneficial Water Right Acquisition Beneficial Controlling/Restricting Agricultural Practice Beneficial Controlling/Removing Exotic Vertebrates Beneficial Controlling/Removing Domestic Animals Adverse Predation Existing Predation Adverse Water Temperature Alteration Existing Water Temperature Alteration Adverse Water Level Fluctuation Existing Water Level Fluctuation Adverse Groundwater drawdown Existing Groundwater drawdown Adverse Irrigating Existing Irrigating Adverse Dredging Existing Dredging Adverse Competition Existing Competition Adverse Exotic/Feral/Introducted Species Existing Exotic/Feral/Introducted Species Adverse Grazing Existing Grazing Adverse Existing COMMENTS ON MANAGEMENT PRACTICES - The primary threat to the Railroad Valley springfish is the alteration of its thermal spring habitat (03,05,15,16). The outflow of Big Warm Spring, on the Duckwater Shoshoe Indian Reservation, contains a cement structure which splits flow into two channels for agriculture; one of these channels provides flow to a commercial catfish-rearing facility (05). The Little Warm Spring system, also on the Duckwater Reservation, was recently (1984) channelized for several hundred meters (15). Outflows of all springs at Lockes Ranch have been altered by channelization and diversion (05,15,17). These activities resulted in an increased temperature in the Big Spring ouflow, thereby impacting spawning areas (05). Introduction of exotic species, particulary fishes, also threatens the Railroad Valley springfish. Guppies (Poecilia reticulata) have been introduced into Big Warm Spring (05,15,16), and have apparently competitively excluded C. nevadae from the headpool and portions of one outflow due to changed habitat conditions (decreased water depth and velocity) which are now condusive to P. reticulata (15). Catfish (Ictalurus punctatus) have escaped from the rearing facility into the outflow channel and headpool. Predation by I. punctatus on desert fishes has been well documented (05). Management Practices - 1 (DRAFT) - Management Practices Species SPRINGFISH, RAILROAD VALLEY Species Id ESIS251026 Date 14 MAR 96 Groundwater pumping and/or potential for interference with underground aquifers in Railroad Valley is increasing due to oil and gas development, and Desert Land Entry and Carey Act applications to the Bureau of Land Management (05,15). Although ground water resources are regulated by the Nevada State Engineer, the possibility of local "cones of depression" in ground water levels, consequently affecting spring discharge, is recognized by the State Engineer (05). The discharge of Big Spring at Lockes Ranch decreased significantly after a well was drilled nearby (10). Similarly, decreased flow at Chimney Spring in 1981 caused the demise of the introduced C. nevadae population there. All spring habitats at Lockes Ranch are also impacted by livestock grazing (05,15,19). Although not proven to eliminate springfish populations, over-grazing is known to degrade the quality of aquatic habitats (01,14). Prior to Federal listing as Threatened with Critical Habitat, regulatory mechanisms for protection of C. nevadae were limited to its listing by the State of Nevada as a protected species. While this classification prohibited taking without a scientific collecting permit issued by the State, it included no habitat protection or provisions for development of management or recovery plans (05). UNAPPROVED PLAN: The technical draft recovery plan for the Railroad Valley springfish (Crenichthys nevadae) is scheduled for completion by March 1987. Agency draft is scheduled for completion by January 1988, and the final plan is scheduled for completion by December 1988. No approved recovery plan exists. At present, Fish and Wildlife Service biologists consider the species will be recovered when native habitats in Railroad Valley have been secured through, but not limited to, the following: (1) acquistion activities at the Locke's Ranch spring complex; (2) controlling/restricting agricultural activities at both Locke's Ranch and the Duckwater Indian Reservation (i.e prevent further damage by cattle grazing - the past damage and any future will require habitat rehabilitation and revegetation) (cattle grazing has not been proven to eliminate springfish populations, but the overgrazing is known to degrade the quality of the aquatic habitat (01,14)); (3) modifying operation of the commercial catfish facility at Big Warm Springs to prohibit escape of channel catfish into the spring outflow; (4) protection of the underground aquifer supplying springs where C. nevada occurs (i.e prevent water draw-down to maintain water flow in springs); (5) possible establishment of additional populations of C. nevadae within the historical watershed or possible elsewhere if suitable native habitat is non-existenct or marginal. The recovery activities undertaken as of 1987 for C. nevadae have consisted of Nevada Department of Wildlife/Bureau of Land Management actions to establish a population in Chimney Hot Springs, on Bureau of Land Management administered land south of Locke's Ranch. The population at Sodaville, in Mineral County, was introduced by a Nevada Department of Wildlife employee in 1947. The population in Hot Creek Management Practices - 2 (DRAFT) - Management Practices Species SPRINGFISH, RAILROAD VALLEY Species Id ESIS251026 Date 14 MAR 96 Canyon was an unauthorized introduction by an unknown individual(s). Management Practices - 3
                                   (DRAFT) - References
                           Species SPRINGFISH, RAILROAD VALLEY
                                  Species Id ESIS251026
                                      Date 14 MAR 96



     

References

***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE ***** 01 Bureau of Land Management. 1975. Effects of livestock grazing on wildlife, watershed, recreation, and other resource values in Nevada. U.S. Dept. of Interior. 02 Deacon, J.E. 1984. Population status and distribution of Gila complex in Hot Creek Valley, Hot Creek canyon, and Little Fish Lake valley. Rept. to: NV Dept. of Wildl., Reno, Proj. E-1-1, Job 1. 03 Deacon, J.E., T.B. Hardy, J. Pollard, W. Taylor, J. Landye, J. Willimas, C. Williams, P. Gregor, and M. Conrad. 1980. Environmental analysis of four aquatic habitats in east-central Nevada, June-September, 1980. Final Rept. to: HDR Sciences. 123 pp. 04 Deacon, J.E. and J.E. Williams. 1984. Annotated list of the fishes of Nevada. Proc. Biol. Soc. Wash. 97(1):103-118. 05 U.S. Fish and Wildlife Service. 1986. Endangered and threatened wildlife and plants; determination of threatened status and critical habitat for the Railroad Valley Springfish: Final Rule. March 31, 1986. Fed. Reg. 51:10857-10865. 06 Garside, L.J. and J.H. Schilling. 1979. Thermal waters of Nevada. NV Bur. of Mines and Geology Bull. 91, Univ. of NV, Reno. 163 pp. 07 Hubbs, C.L. 1932. Studies of the fishes of the Order Cyprinodontes. XII. A new genus related to Empetrichthys. Occ. Papers Mus. Zool. Univ. Mich. No. 252:1-5. 08 Lagler, K.F., J.E. Bardach, and R.R. Miller. 1962. Ichthyology. John Wiley and Sons, Inc., New York. 545 pp. 09 La Rivers, I. 1962. Fishes and fisheries of Nevada. NV. Fish and Game Comm., Carson City. pp. 517-520. 10 Mifflin, M.D. 1968. Delineation of ground water flow systems in Nevada. Desert Res. Inst. Tech. Rept. Ser. H-W. Publ. 4:1-110. 11 Nelso, J.S. 1976. Fishes of the world. John & Wiley Sons, New York. pp. 170-178. 12 Parenti, L.R. 1981. A phylogentic and biogeographic analysis of Cyprinodontiformes fishes (Teleostei, Atherinomorpha). Bull. Amer. Mus. Nat. Hist. 168:341-557. 13 Pedretti, J.W., T.M. Baugh, and J.E. Deacon. 1985. Status of Crenichthys nevadae in portions of Railroad Valley, NV. Rept. to: NV Dept. of Wildl., Reno. 11 pp. 14 Platts, W.S. 1982. Livestock and riparian-fishery interactions: what are the facts. Trans. 47th N. Amer. Wildl. Nat. Res. Conf., 1982. pp. 507-515. 15 Williams, C.D. 1986. Life history of the Railroad Valley springfish, Crenichthys nevadae Hubbs (Cyprinodontidae), of east-central Nevada. MS thesis. Dept. of Biol., CA State Univ., Sacramento. 124 pp. 16 Williams, C.D. and J.E. Williams. 1981. Distribution and status of native fishes of the Railroad Valley system, Nevada. Cal-Neva Wildl. Trans. pp. 48-51. 17 Williams, C.D. and J.E. Williams. 1982. Summer food habits of fishes from two springs in east-central Nevada. Southwestern References - 1 (DRAFT) - References Species SPRINGFISH, RAILROAD VALLEY Species Id ESIS251026 Date 14 MAR 96 Naturalist 27(4):437-445. 18 Withers, D. 1986. Status of Crenichthys nevadae at Big and Little Warm Springs. Field trip rept. NV Dept. of Wildl., Las Vegas. 8 pp. 19 Withers, D. 1986. Status of springfish at Lockes Ranch, Railroad Valley. Field trip rept. NV Dept. of Wildl., Las Vegas. 5 pp. ***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY ***** 01 U.S. Fish and Wildlife Service. 1986. Endangered and threatened wildlife and plants; determination of threatened status and critical habitat for the Railroad Valley Springfish: Final Rule. March 31, 1986. Fed. Reg. 51:10857-10865. 02 Hubbs, C.L. and R.R. Miller. 1948. The zoological evidence; correlation between fish distribution and hydrographical history in the desert basins of western United States. pp. 17-144. In: The Great Basin, with emphasis on glacial abd postglacial times. Bull. Univ. Utah 38(20). 03 Hubbs, C.L., R.R. Miller and L.C. Hubbs. 1974. The hydrographic history and relect fishes of the north-central Great Basin. Memoirs Calif. Acad. Sci. 7:1-259. 04 Mifflin, M.D. and M.M. Wheat. 1979. Pluvial lakes and estimated pluvial climates of Nevada. Nev. Bur. Mines Geol. Bull. 94 57 pp. 05 Miller, R.R. 1958. Origin and affinities of the freswater fish fauna of western North America. pp. 187-222. In: Zoogeography, C.L. Hubbs (ed.) Am. Assoc. for the Advancement of Sci., Baltimore. Publ. No. 51. 06 Pedretti, J.W., T.M. Baugh, and J.E. Deacon. 1985. Status of Crenichthys nevadae in portions of Railroad Valley, NV. Rept. to: NV Dept. of Wildl., Reno. 11 pp. 07 Williams, C.D. 1986. Life history of the Railroad Valley springfish, Crenichthys nevadae Hubbs (Cyprinodontidae), of east-central Nevada. MS thesis. Dept. of Biol., CA State Univ., Sacramento. 124 pp. 08 Williams, C.D. and J.E. Williams. 1981. Distribution and status of native fishes of the Railroad Valley system, Nevada. Cal-Neva Wildl. Trans. pp. 48-51. References - 2