Rio Grande del Norte (Baird and Girard 1853).
Etymology/Derivation of Scientific Name
Cyprinodon – Greek meaning “toothed carps”; elegans – Latin meaning “elegant” (Edwards 1999).
Maximum size: 62 mm TL (Page and Burr 1991).
Coloration: Dorsal speckled at base; basal exposed part of lateral scales darker than edge; lateral blotches of female longer than deep; dark terminal caudal bar of adult males about one-third of caudal length (Hubbs et al. 2008). Page and Burr (1991) described coloration as follows: brown-black blotches form “stripe” (often faint on male long silver side; additional blotches on upper and lower side of female. Gray-green above; pale yellow to white below; clear to light orange fins. Large male has black specks on silver side, black edge on caudal fin (Page and Burr 1991).
Counts: Lateral scale rows 24 or 25 (Hubbs et al. 2008). Page and Burr (1991) listed counts as follows: 25-28 lateral scales; 10-12 dorsal rays; 9-11 anal rays; usually 6-7 pelvic rays; 19-22 rakers on 1st gill arch.
Mouth position: Upturned (Page and Burr 1991).
Body shape: Relatively streamlined (Garrett et al. 2002); distance from origin of dorsal fin to end of hypural plate less than the distance from origin of dorsal to anterior nostril (Hubbs et al. 2008).
External morphology: Abdomen fully scaled (Hubbs et al. 2008).
Echelle (1975) studied morphological variation in Cyprinodon elegans: specimens from Phantom Lake Spring and Toyah Creek differed from each other in degree of belly scalation and numbers of dorsal and caudal fin rays; the Griffin and San Solomon Springs populations were intermediate (Echelle 1975; U.S. Fish and Wildlife Service 1981).
Distribution (Native and Introduced)
Texas distribution: Restricted to small series of springs and their outflows, and man-made irrigation canals in the area of Balmorhea, Texas, including Phantom Springs (Jeff Davis County), San Solomon Springs, Giffin Springs and Toyah Creek (Reeves County; Guillory 1980; Hubbs et al. 2008). Native range: Comanche, Phantom Cave, San Solomon springs (Pecos and Reeves counties; Minckley et al. 1991).
Abundance/Conservation status (Federal, State, NGO)
Endangered (Texas); Endangered (Federally; Hubbs et al. 2008). The Comanche Springs (Pecos County, Texas) population was extirpated when the springs were pumped dry (Guillory 1980; Hubbs et al. 2008). Listed as Endangered by the American Fisheries Society (Jelks et al. 2008); categories of threats: present or threatened destruction, modification, or reduction of habitat or range; natural or anthropogenic factors that affect the existence of this species, including impacts of nonidigenous organisms, hybridization, competition, and/or predation; and a narrowly restricted range. Edwards (2001) and Garrett et al. (2002) encouraged implementation of recommendations in the Comanche Springs pupfish recovery plan (U.S. Fish and Wildlife Service 1981) and suggested that additional efforts be directed to the Phantom Springs system. Minckley et al. (1991) reported this species as Endangered due to overpumped groundwater, habitat alteration, and exotic species. Cyprinodon elegans threatened by failing spring flows, and hybridization and competition with the introduced sheepshead minnow (Cyprinodon variegatus; U.S. Fish & Wildlife Service 1981; Garrett and Edwards 2001; Garrett et al. 2002).
Macrohabitat: Species now inhabits modified springs, various irrigation canals and refugia designed to resemble the original natural habitat (Garrett et al. 2002). Spring-marsh complex and irrigation outflows (Minckley et al. 1991).
Mesohabitat: The springs inhabited by this species have constant discharge, but downstream water levels vary with irrigation demands; species inhabits canals characterized by swift currents; species rarely found in concrete flumes where water depth is less than 10 cm and/or bottom scoured of debris, but is often abundant in earthen ditches and concrete flumes 10 cm or more in depth with bottoms covered by debris and Chara (Guillory 1980). Gelhbach (1978) reported critical thermal maxima of approximately 40.5°C for this species, and suggested that a temperature range of 20-30°C in August-September be maintained for this species in an artificial refuge. See Edwards (1999) for listings of native fishes and introduced fishes that may co-occur with Cyprinodon elegans.
Spawning habitat: Breeding territories variable in size (average 0.5 m²) and most often located over algal mats in relatively swift water; eggs apparently laid singly onto algal mat substrates of the male’s territory (Itzkowitz 1969; Edwards 2001).
Spawning behavior: Spawning occurs in territories defended and maintained by males; this species breeds in swifter water than any other Cyprinodon; males orient and maintain position upstream from their territories until a female enters the territory and positions herself near the algal mat substrate; courtship behavior similar to that of other species of Cyprinodon (Itzokowitz 1969; Edwards 2001). Breeding system characterized by three different male mating tactics: territorial defense, satellite positioning, and sneak spawning; mating tactic adopted by a male reflected size of the particular male; territorial residents were largest, satellites were medium-sized, and sneakers were the smallest adult males observed (Leiser and Itzkowitz 2002). Brannan et al. (2003) reported that Cyprinodon elegans exhibited courtship and agonistic behaviors, including territorial disputes similar to other Cyprinodon species; species also used visual cues to identify territory.
Fecundity: Aquarium studies suggest females may lay 30 eggs per day and eggs hatch in 5 days at 20°C (Cokendolpher 1978; Edwards 2001).
Age/size at maturation: Cokendolpher (1978) reported that sexual maturity was reached by the fifth month of life.
Growth and Population structure: Adult population densities are 1000 or more in the vicinity of San Solomon Springs and several thousand occur in the irrigation ditches between Phantom Cave and San Soloman Spring (Echelle 1975). In the Balmorhea State Park refugium canal, population size estimated to range from 968-6480 (Garrett and Price 1993; Garrett et al. 2002). During 1999 to 2001 in San Solomon Cienega the population averaged 270,000 in summer to approximately 18,000 in winter (Edwards 2001).
Food habits: Consumed mostly filamentous algae and some snails (Cochliopa texana; Winemiller and Anderson 1997). According to Minckley and Arnold (1969) no observations of pit excavation (a behavioral feeding adaptation) have ever been recorded for Cyprinodon elegans.
Phylogeny and morphologically similar fishes
This species is one of the most distinctive members of the genus Cyprinodon; males possess a unique speckled color pattern and all individuals have a relatively streamlined body shape; individuals lack the vertical bars on the sides of their bodies that are found in most other Cyprinodon (U.S. Fish and Wildlife Service 1981; Edwards 1999, 2001). C. elegans known to hybridize with the sheepshead minnow (C. variegatus; Stevenson and Buchanan 1973; Echelle and Echelle 1994; Tech 2006).
Commercial or Environmental Importance
Conservation actions include the construction in 1974 of a small refugium canal in Balmorhea State Park, the construction of a refugium canal at Phantom Lake Spring in 1993 by the Bureau of Reclamation, and the construction of San Solomon Cienega in 1996; all of which have increased numbers and security of this species, however each remains dependent on spring flows (Edwards 1999, 2001; Garrett et al. 2002). A genetic stock is maintained by the United States Fish and Wildlife Service at the Dexter National Fish Hatchery, New Mexico to provide fish for reintroduction efforts and for research (U.S. Fish and Wildlife Service 1981; Edds and Echelle (1989).
[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Hubbs (1954); Liu (1969); Davis (1979); Echelle et al. (1987); Echelle and Echelle (1998); Echelle
et al. (2005).]
Baird, S.F. and C. Girard. 1853. Descriptions of new species of fishes collected by Mr. John H. Clark, on the U. S. and Mexican Boundary Survey, under Lt. Col. Jas. D. Graham. Proceedings of the Academy of Natural Sciences of Philadelphia 6(7):387-390.
Brannan, D.K., C.R. Brannan, and T.E. Lee, Jr. 2003. Reproductive and territorial behavior of Comanche Springs pupfish (Cyprinodon elegans) in San Solomon Spring pool, Balmorhea State Park, Reeves County, Texas. The Southwestern Naturalist 48(1):85-88.
Cokendolpher, J. C. 1978. Cyprinodon elegans (Cyprinodontidae). American Currents 6 (Jan-March):6-11.
Davis, J.R. 1979. Die-offs of an endangered pupfish, Cyprinodon elegans (Cyprinodontidae). The Southwestern Naturalist 24(3):534-536.
Echelle, A.A. 1975. A multivariate analysis of variation in an endangered fish, Cyprinodon elegans, with an assessment of population status. Texas Journal of Science 26(3/4):529-538.
Echelle, A.F. and A.A. Echelle. 1994. Assessment of genetic introgression between two pupfish species, Cyprinodon elegans and C. variegatus (Cyprinodontidae), after more than 20 years of secondary contact. Copeia 1994(3):590-597.
Echelle, A.A. and A.F. Echelle. 1998. Evolutionary relationships of pupfishes in the Cyprinodon eximius complex (Atherinomorpha: Cyprinodontiformes). Copeia(4):852-865.
Echelle, A.A., A.F. Echelle, and D.R. Edds. 1987. Population structure of four pupfish species (Cyprinodontidae, Cyprinodon) from the Chihuahuan Desert region of New Mexico and Texas – allozymic variation. Copeia 3:668-681.
Echelle, A.A., E.W. Carson, A.F. Echelle, R.A. van den Bussche, T.E. Dowling, and A. Meyer. 2005. Historical biogeography of the new-world pupfish genus Cyprinodon (Teleostei: Cyprinodontidae). Copeia 2:320-339.
Edds, D.R., and A.A. Echelle. 1989. Genetic comparisons of hatchery and natural stocks of small endangered fishes – Leon Springs pupfish, Comanche Springs pupfish, and Pecos gambusia. Transactions of the American Fisheries Society 118(4):441-446.
Edwards, R.J. 1999. Ecological profiles for selected stream-dwelling Texas freshwater fishes II. Report to the Texas Water Development Board. 69 pp.
Edwards, R.J. 2001. Ecological profiles for selected stream-dwelling Texas freshwater fishes III. Report to the Texas Water Development Board. 59 pp.
Garrett, G.P., and A.H. Price. 1993. Comanche Springs pupfish (Cyprinodon elegans) status survey. Final Report, Endangered Species Act, Section 6,
Garrett, G.P., and R.J. Edwards. 2001. Regional ecology and environmental issues in West Texas, Chapter 5. pp. 56-65 in: Mace, R.E., W.F. Mullican, Jr., and E.S. Angle (Eds.). Aquifers of West Texas. Texas Water Development Board.
Garrett, G.P., C. Hubbs, and R.J. Edwards. 2002. Threatened fishes of the world: Cyprinodon elegans Baird & Girard, 1853 (Cyprinodontidae). Environmental Biology of Fishes 65(3):288-288.
Gehlbach, F.R., C.L. Bryan, and H.A. Reno. 1978. Thermal ecological features of Cyprinodon elegans and Gambusia nobilis, endangered Texas fishes. Texas Journal of Science 30(1):99-101.
Guillory, V. 1980. Cyprinodon elegans (Baird and Girard), Comanche Springs pupfish. pp. 495 in D. S. Lee et al., Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.
Hubbs, C. 1954. Corrected distributional records for Texas fresh-water fishes. Texas Jornal of Science 1954(3):277-291.
Hubbs, C., R.J. Edwards, and G.P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement, 2nd edition 43(4):1-87.
Itzkowitz, M. 1969. Observations on the breeding behavior of Cyprinodon elegans in swift water. Texas Journal of Science 21(2):229-231.
Jelks, H.L., S.J. Walsh, N.M. Burkhead, S. Contreras-Balderas, E. Diaz-Pardo, D.A. Hendrickson, J. Lyons, N.E. Mandrak, F. McCormick, J.S. Nelson, S.P. Platania, B.A. Porter, C.B. Renaud, J.J. Schmitter-Soto, E.B. Taylor, and M.L. Warren, Jr. 2008. Conservation status of imperiled North American freshwater and diadromous fishes. Fisheries 33(8):372-407.
Leiser, J.K. and M. Itzkowitz. 2002. The relative costs and benefits of territorial defense and the two conditional male mating tactics in the Comanche Springs pupfish (Cyprinodon elegans). acta ethol 5:65-72.
Liu, R.K. 1969. The comparative behavior of allopatric species (Teleostei – Cyprinodontidae: Cyprinodon). Ph.D. Dissertation, Univ. California, Los Angeles. 185 pp.
Minckley, W.L., and E.T. Arnold. 1969. “Pit digging" - A behavioral feeding adaptation in pupfishes (Genus Cyprinodon). Journal of the Arizona Academy of Science 5:254-257.
Minckley, W.L., G.K. Meffe, and D.L. Soltz. 1991. Conservation and management of short-lives fishes: the cyprinodontoids, Chapter 15. pp. 247-282 in: Minckley, W.L., and J.E. Deacon (Eds.). Battle Against Extinction: Native Fish Management in the American West. University of Arizona Press, Tucson, Arizona. 517 pp.
Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston, Massachusetts. 432 pp.
Stevenson, M.M. and T.M. Buchanan. 1973. Analysis of hybridization between cyprinodont fishes Cyprinodon variegatus and Cyprinodon elegans. Copeia 4:682-692.
Tech, C. 2006. Postzygotic incompatibilities between the pupfishes, Cyprinodon elegans and Cyprinodon variegatus: hybrid male sterility and sex ratio bias. Journal of Evolutionary Biology 19(6):1830-1837.
U.S. Fish & Wildlife Service. 1981. Comanche Springs pupfish (Cyprinodon elegans) recovery plan. U.S. Fish & Wildlife Service, Albuquerque. 24 pp.
Winemiller, K.O. and A.A. Anderson. 1997. Response of endangered desert fish populations to a constructed refuge. Restoration Ecology 5(3):204-213.