Notropis chihuahua

Chihuahua shiner

Type Locality

Rio de los Conchos at Chihuahua, Chihuahua, Mexico (Woolman 1892).

Etymology/Derivation of Scientific Name

Notropis – ridged or keeled back; a misnomer, probably due to the shrunken specimen used by Rafinesque when establishing this genus for N. atherinoides; chihuahua – from the Chihuahua Desert (Scharph 2005).

Synonymy

Characters

Maximum size: 64 mm SL (Burr 1980; Burr and Mayden 1981).

Coloration: Numerous macromelanophores widely scattered over dorsum, opercle, beneath eye and sides of snout; black wedge on caudal fin base. Lateral line pores at front outlined in black. Yellow to pale orange lips and dorsal, caudal, and pectoral fins. Straw yellow above, often a dusky stripe along back; dusky (at front) to black (at rear) stripe on silver side; white below. Peritonium silvery (Burr and Mayden 1981; Hubbs et al. 1991; Page and Burr 1991).

Counts: Pharyngeal teeth 0,4-4,0; 33-37 lateral line scales; usually 7 anal fin rays; fewer than 10 soft rays on dorsal fin (Burr and Mayden 1981; Hubbs et al. 1991).

Mouth position: Subinferior and horizontal (Hubbs et al. 1991).

Body shape: Stout, barely compressed body, deepest under nape; dorsal fin origin over pelvic fin origin; rounded snout (Page and Burr 1991); distance from origin of anal fin to end of caudal peduncle contained two and one-half or fewer times in distance from tip of snout to origin of anal fin (Hubbs et al. 1991).

External morphology: Lateral line scales not markedly elevated anteriorly, height one or two times width; lateral line complete; last ray of dorsal fin much less than one-half the length of the longest; first obvious dorsal fin ray a thin splint, closely attached to the following well developed but unbranched ray, especially at tip; lower lip thin, without a fleshy lobe; lateral line usually not decurved, either straight or with a broad arch; premaxillaries protractile; upper lip separated from skin of snout by a deep groove continuous across the midline; cartilaginous ridge of lower jaw hardly evident (Hubbs et al. 1991). Tubercles consistently well developed in breeding males, less so in non-breeding males and absent in females; tubercles develop at small sizes (juvenile male 29 mm SL with tubercles developed on head and median pectoral rays; Burr and Mayden 1981).

Internal morphology: Teeth with prominent terminal hooks, but with very narrow grinding surfaces; intestine short with single lengthwise loop; swim bladder large, two chambered (Burr and Mayden 1981).

Distribution (Native and Introduced)

Mexico distribution: Smaller tributaries of Rio Conchos in Chihuahua and Durango, Mexico (Burr 1980; Hubbs et al. 1991).

Texas distribution: Limited to smaller tributaries of the Rio Grande in the Big Bend region (Hubbs 1940; Hubbs 1957; Hubbs et al. 1977; Burr 1980; Hubbs et al. 1991).

Abundance/Conservation status (Federal, State, NGO)

Threatened, Texas (Miller 1972; Hubbs et al. 1991). Imperiled, Mexico (Scharph 2005).

Habitat Associations

Macrohabitat: Typically occurs in small to medium-sized streams (Burr and Mayden 1981).

Mesohabitat: Mid-water or bottom-swelling species (frequently captured at depths of 0.5-1.5 m), usually found over gravel to sand substrate, in clear, cool, moving waters; also collected over rubble bottom with some boulders, bedrock and mud; vegetation (usually Potamogeton, Chara, or an eel grass) may be present (Burr 1980; Burr and Mayden 1981).

Biology

Spawning season: Protracted season lasts from March to early August (Burr 1980; Burr and Mayden 1981).

Spawning habitat: Species may use Tornillo Creek, Texas for breeding and rearing young (Hubbs and Wauer 1973).

Spawning Behavior:

Fecundity: Females (ranging from 41-51 mm SL) contain 452-892 mature ova; smallest ova ranged from 0.1-0.2 mm, intermediate-sized ova from 0.3-0.5 mm, mature ova from 0.7-1.0 mm; mature ova were pinkish-yellow (Burr and Mayden 1981).

Age at maturation: 

Migration:

Growth and Population structure:  Sex ratio varies from 1.6 males:1 female to 1.3 males:1 female (Burr and Mayden 1981).

Longevity: At least 2 years (Burr and Mayden 1981).

Food habits: Intestinal contents reveal preference for small aquatic insects: Chironomidae larvae, Plecoptera larvae, and Coleoptera adults (Burr and Mayden 1981). A 29 mm TL specimen contained insect parts – Diptera (Runyan 2007).

Phylogeny and morphologically similar fishes

Limited comparison of similar species follows:  See Burr and Mayden (1981) for further comparison of selected morphologically similar species including N. stramineus, N. girardi, N. bairdi, N. buccula, N. volucellus, N. buchanani, and N. braytoni. Notropis chihuahua differs from the sand shiner (N. stramineus) in its melanophore size and pattern (having a distinctive macromelanophore pattern) and in having a weakly developed predorsal stripe; the Arkansas River shiner (N. girardi) differs from N. chihuahua in apparently lacking breeding colors; the smalleye shiner (N. buccula) differs in apparently lacking breeding colors, and in males having only 1 or 2 rows of small uniserial tubercles per ray on rays 2-6 of the pectoral fin rather than the characteristic shagreen pattern of N. chihuahua; the male Red River shiner (N. bairdi) differs in having only 1 or 2 rows of small uniserial tubercles per ray on rays 2-6 of the pectoral fin rather than the characteristic shagreen pattern of N. chihuahua. The mimic shiner (N. volucellus) has total scale radii 11-17 (13.1); the ghost shiner (N. buchanani) has total scale radii 1-10 (4.9); and the Tamaulipas shiner (N. braytoni) has total scale radii 9-18 (13.4); these three species are only superficially similar to N. chihuahua which has total scale radii 12-28 (17.1) (Burr and Mayden 1981).

According to Hubbs and Hubbs (1958), Notropis chihuahua possibly close to species including the following whose range includes Texas: N. braytoni, N. volucellus and/or N. buchanani (Burr 1980).

Host Records

Nematodes were found in the intestines of some specimens; in a 56 mm SL female one nematode measured 32 mm TL

(Burr and Mayden 1981).

Commercial or Environmental Importance

Species subject to some periodic fluctuations in population numbers in the Big Bend region probably due to introduction of exotics and fluctuations in the water table (Hubbs and Wauer 1973; Burr and Mayden 1981). Burr and Mayden (1981) noted that the species did not appear threatened by man-made changes that were rapidly destroying available habitat, but suggested that its status be closely monitored to assess any major changes that could decrease the population. Edwards et al. (2002) reported that the tributary creeks critical to the breeding and rearing of young are severely threatened by water depletion.

[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Huber and Rylander (1992).]

References

Burr, B.M.  1980.  Notropis chihuahua (Woolman), Chihuahua shiner.  p. 251.  In: D. S. Lee, C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister & J. R. Stauffer, Jr. (eds.), Atlas of North American freshwater fishes, North Carolina State Museum of Natural History, Raleigh, 854 pp.

Burr, B.M., and R.L. Mayden. 1981. Systematics, distribution, and life history notes on Notropis Chihuahua (Pisces: Cyprinidae). Copeia 1981(2):255-265.

Edwards, R.J., G.P. Garrett, and E. Marsh-Matthews. 2002. Conservation and status of the fish communities inhabiting the Rio Conchos basin and middle Rio Grande, Mexico and U.S.A. Review in Fish Biology and Fisheries 12:119-132.

Hubbs, C. 1957. Distributional patterns of Texas fresh-water fishes. The Southwestern Naturalist 2(2/3):89-104.

Hubbs, C., and R. Wauer. 1973. Seasonal changes in the fish fauna of Tornillo Creek, Brewster County, Texas. The Southwestern Naturalist 17(4):375-379.

Hubbs, C., R.J. Edwards, and G.P. Garrett. 1991. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement 43(4):1-56.

Hubbs, C., R.R. Miller, R.J. Edwards, K.W. Thompson, E. Marsh, G.P. Garrett, G.L. Powell, D.J. Morris, and R.W. Zerr. 1977. Fishes inhabiting the Rio Grande, Texas and Mexico, between El Paso and the Pecos confluence. Contributed Paper, Symposium on the importance, preservation and management of the riparian habitat, July 9, 1977, Tuscon, Arizona.

Hubbs, C.L. 1940. Fishes from the Big Bend Region of Texas. Trans. Tex. Acad. Sci. 23:3-12.

Hubbs, C.L., and C. Hubbs. 1958. Notropis saladonis, a new cyprinid fish endemic in the Rio Salado of northeastern Mexico. Copeia 1958(4):297-307.

Huber, R., and M.K. Rylander. 1992. Brain morphology and turbidity preference in Notropis and related genera (Cyprinidae, Teleostei). Environmental Biology of Fishes 33:153-165.

Miller, R.R. 1972. Threatened freshwater fishes of the United States. Trans. Amer. Fish. Soc. 101(2):239-252.

Page, L. M. & B. M. Burr.  1991.  A field guide to freshwater fishes of North America north of Mexico.  Houghton Mifflin Company, Boston, Massachusetts. 432 pp.

Runyan, D.T. 2007. Fish assemblage changes in western Gulf Slope drainages: An historical perspective and distribution and diet of larval and juvenile fishes in the Rio Grande, Texas. M.S. Thesis. Texas State University – San Marcos. 85 pp.

Scharpf, C. 2005. Annotated checklist of North American freshwater fishes, including subspecies and undescribed forms, Part 1: Petromyzontidae through Cyprinidae. American Currents, Special Publication 31(4):1-44.

Woolman, A.J. 1892. New fishes from Chihuahua, Mexico. Amer. Nat. 26:259-261.