Picture by Chad Thomas, Texas State University-San Marcos



Machrybopsis tetranema

peppered chub



Type Locality

Elm and Spring creeks at Medicine Lodge (Barber County, Kansas; Gilbert 1886).


Etymology/Derivation of Scientific Name

Macr – Greek, meaning “long”, referring to elongated forms of Hybopsis; tetra – four, and nema – thread, referring to the four threadlike barbels of this species (Scharpf 2005). Common name, peppered chub, refers to the black spots on the body (Eisenhour 1999).



Eisenhour (1999) recognized Macrhybopsis tetranema as distinct species within the M. aestivalis complex. See Eisenhour (1997) for complete synonymy.


Hybopsis tetranemus Gilbert 1886:208-209.

Hybopsis aestivalis tetranemus Bottrell et al. (1964); Davis and Miller (1967); Williams et al. 1989:5.

Extrarius aestivalis tetranemus Sublette et al. (1990); Cross and Collins 1995:15,62.

Macrhybopsis aestivalis tetranemus Propst (1999).

Macrhybopsis tetranema Eisenhour (1999, 2004); Hubbs et al. 2008:21.



Maximum size: 77 mm (3.03 in) TL (Bonner 2000, Eisenhour 1999).


Coloration: Pigment nearly confined to dorsal half of body; medium-large melanophores scattered over dorsolateral surface; some individuals with few scales bearing clusters (2-8) of medium-sized melanophores; smaller melanophores randomly scattered, usually not concentrated on margin or submargin of scales; lateral stripe poorly defined and centered one scale row above lateral line; small pale areas often present at posterior and anterior base of dorsal fin; head with pigment over brain, and preorbital bar present but often indistinct; dorsal fin rays weakly pigmented, darker at bases; pigmentation lacking on pectoral, pelvic, and anal fins; caudal fin with white ventral border, the rays poorly pigmented and darker at base of each caudal lobe (Eisenhour 1999).


Counts: Pharyngeal teeth 0,4-4,0; 8 dorsal fin soft rays; usually 19 (15-21) principal caudal fin soft rays; usually 8 (7-9) anal fin soft rays; usually 8 (6-9) pelvic fin soft rays; usually 13-16 (12-18) pectoral fin soft rays; usually 37-43 (35-38) lateral line scales; usually 13-17 (2-20) predorsal scales; usually 5-6 (4-8) scales above lateral line; usually 5 (4-7) scales below lateral line; usually 12-16 (12-18) caudal peduncle scales; usually 12-16 (9-19) infraorbital pores; usually 10-13 (9-15) preoperculomandibular pores; usually 36-38 (36-39) total vertebrae; usually 17-18 (16-19) precaudal vertebrae; usually 19-20 (19-21) caudal vertebrae (Eisenhour 1999). Eisenhour (1999) listed averages of counts for specimens from the South Canadian River: lateral line scales 42 (range 39-48); caudal peduncle scales 14 (range 12-17).


Mouth position: Inferior and horizontal (Eisenhour 1999); mouth width slightly narrower than head when viewed ventrally.


Body shape: Fusiform, fairly deep at dorsal-fin origin, but rapidly tapering anteriorly to narrow, pointed head and posteriorly to moderately slender caudal peduncle; dorsal fin directly above or just ahead of anal fin origin; head conical, flattened ventrally with long and relatively pointed snout; lips fleshy and thickened posteriorly; eyes round (or nearly so) (Eisenhour 1999).


Morphology: Two distinct pairs of barbels present, length of posterior pair usually greater than orbit length, length of shorter pair usually greater than 50% of orbit length; large taste buds present over most of body, enlarged into barbel-like papillae on gular area; gillrakers absent or present as 1-3 dorsal rudiments (Eisenhour 1999). Anal and dorsal fins slightly falcate; pelvic fins rounded; pectoral fins long, falcate, and just reaching bases of pelvic fins in adult males; adult females with shorter and pointed pectoral fins, usually not reaching pelvic fin bases (Eisenhour 1999). Nape fully scaled (in about 97% of specimens examined); belly posterior to pelvic bases partially scaled and belly anterior to pelvic bases usually naked (Eisenhour 1999). Pectoral rays 2-10 greatly thickened in large nuptial males, bearing rows of small, conical, antrorse tubercles. Basal part of rays bears 1-2 rows of tubercles. Usually two tubercles per segment on posterior primary branch, 1-2 tubercles per segment on anterior primary branch. Some specimens with tubercles arranged uniserially on both primary branches. Tubercles arranged uniserially on secondary branches. Females without tubercles (Eisenhour 1999).


Distribution (Native and Introduced)

U.S. distribution: Historically widespread in western reaches of the Arkansas River basin from central Oklahoma westward to Colorado and New Mexico (Eisenhour 1997; Luttrell et al. 1999); however this species is presently found only in the Ninnescah River and an associated portion of the Arkansas River mainstem in Kansas, and the South Canadian River between Ute Reservoir in New Mexico and Meredith Reservoir in the Texas Panhandle (Luttrell et al. 1999; Eisenhour 1999).


Texas distribution: Found only in portions of the upper South Canadian River (Luttrell et al. 1999; Eisenhour 1999; Hubbs et al. 2008).


[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Wilde and Durham (2008).]


Abundance/Conservation status (Federal, State, Non-governmental organizations)

Special Concern (Texas); declining throughout much of natural range (Hubbs et al. 2008). Reported as Critically Imperiled (rangewide; Scharpf 2005); Endangered in Kansas (Cross and Collins 1995; Scharpf 2005); and Threatened in New Mexico (Propst 1999; Scharpf 2005); Sublette et al. (1990) noted classification as State endangered in New Mexico, Group II, first listed 10 February 1978. Extirpated from Arkansas (Robinson and Buchanan 1988; Luttrell et al. 1999). Extirpated from Colorado (Luttrell et al. 1999; Scharpf 2005) and Oklahoma (Luttrell et al. 1999; Miller and Robison 2004; Scharpf 2005). Luttrell et al. (1999) reported the species extirpated from about 90% of historic range. Species proposed for federal protection as threatened or endangered (U.S. Fish and Wildlife Service 1994). Williams et al (1989) listed Special Concern status rangewide.


Habitat Associations

Macrohabitat: Large, plains streams (Hubbs et al. 2008); medium to large streams (Eisenhour 2004).


Mesohabitat: Flowing water over coarse sand and fine gravel substrates in streams (Eisenhour 2004); species occupies intermittent streams that may dry to salt-encrusted pools. Among seasons, M. tetranema was collected from Canadian River habitats with shallow water, swift current, and typically with sand substrate (Bonner 2000); specimens inhabiting swifter currents were typically collected from areas of low conductivity (range: 0.7-14.0 mS/cm) and high turbidity (4.3-10,200 NTU).



Spawning season: May- August; M. tetranema spawns multiple times in a given year (Bottrell et al. 1964; Bonner 2000; Durham and Wilde 2005, 2006).


Spawning habitat: Bonner (2000) reported spawning under both high and low flows, as well as in pools, in the Canadian River (New Mexico and Texas). Bottrell et al. (1964) suggested that eggs are broadcast by breeding females in the deeper part of the stream current; eggs were reportedly found suspended in the main current of the turbid waters of the Cimarron and Arkansas rivers.


Spawning behavior: No information at this time.


Fecundity: Eggs are clear, transparent, nonadhesive, semibuoyant, and pelagic with characteristic circular micropyle; eggs measured about 2.5 mm (0.10 in) in diameter including the chorion; hatching in 24-28 hours after fertilization (Bottrell et al. 1964).


Age at maturation:  No information at this time.


Migration: Likely (Bonner 2000).


Growth and Population structure: Three age groups present (age-0, 1, and 2) in Canadian River (New Mexico and Texas; Bonner 2000). Larval growth rapid (Bottrell et al. 1964; Bonner 2000); Bottrell et al. (1964) reported that one specimen grew 19.05 mm (0.75 in) in three weeks. Durham and Wilde (2005) reported mean daily increase in length (growth) ranged from 0.26-0.75 mm (0.01-0.03 in) per day for young-of-year specimens (based on collections made in 2000 and 2001).


Longevity: Few age-2 fish surviving past their third summer (Bonner 2000).


Food habits: Generalist feeder, with terrestrial and aquatic insects representing 31% (by weight) of diet; detritus represented 25% of the diet, plant materials (28%), and sand-silt (17%); presence of sand-silt in the diet suggests that M. tetranema forages among sediments on the river bottom. Bonner and Wilde (2002) found that prey consumption by M. tetranema was unaffected by increased turbidity. Davis and Miller (1967) stated that this species is primarily a taste-feeder (“mouth taster”); fish observed (in captivity) swimming over the bottom with pectoral fins spread widely and barbels in contact with the sand substrate until cutaneous taste buds on the barbels, fins and body apparently detected food items.


Phylogeny and morphologically similar fishes

Macrhybopsis tetranema is distinguished from all other members of the M. aestivalis complex, the burrhead chub (M. marconis), the prairie chub (M. australis), the speckled chub (M. aestivalis), and the shoal chub (M. hyostoma) in the fact it is the only one of the five chubs to reside in the Canadian River drainage. 


Host Records

 No information at this time.


Commercial or Environmental Importance

Cross and Collins (1995) noted the decline of the Arkansas River (Kansas) population since the 1960’s due to reduced stream flow. Activities resulting in the reduction of surface flows or an elevation in salinity are detrimental to this species (Propst 1999).



Bonner, T. H. 2000. Life history and reproductive ecology of the Arkansas River shiner and peppered chub in the Canadian River, Texas and New Mexico. Doctoral dissertation. Texas Tech University, Lubbock. 147 pp.

Bonner, T.H., and G.R. Wilde. 2002. Effects of turbidity on prey consumption by prairie stream fishes. Trans. Amer. Fish. Soc. (131):1203-1208.

Bottrell, C. E., R. H. Ingersol, and R. W. Jones. 1964. Notes on the embryology, early development, and behavior of Hybopsis aestivalis tetranemus (Gilbert). Trans. Amer. Microscopy Soc. 83:391-399.

Cross, F.B., and J.T. Collins. 1995. Fishes in Kansas. 2nd edition. Univ. Kans. Mus. Nat. Hist. Publ. Ed. Ser. 14:1-315.


Davis, B.J., and R.J. Miller. 1967. Brain patterns in minnows of the genus Hybopsis in relation to feeding habits. Copeia 1967(1):1-39.


Durham, B.W. and G.R. Wilde. 2005. Relationship between hatch date and first-summer growth of five species of prairie-stream cyprinids. Environmental Biology of Fishes 72(1):45-54.


Durham, B.W., and G.R. Wilde. 2006. Influence of stream discharge on reproductive success of a prairie stream fish assemblage. Trans. Amer. Fish. Soc. 135:1644-1653.

Eisenhour, D.J. 1997. Systematics, variation and speciation of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae) west of the Mississippi River. Unpubl. PhD Dissertation. Southern Illinois Univ., Carbondale. 260 pp.

Eisenhour, D.J. 1999. Systematics of Macrhybopsis tetranema (Cypriniformes: Cyprinidae). Copeia 1999(4):969-980.

Eisenhour, D. J. 2004. Systematics, variation, and speciation of the Macrhybopsis aestivalis complex west of the Mississippi River. Bulletin Alabama Museum of Natural History 23:9-48.

Gilbert, C.H. 1886. Third series of notes on Kansas fishes. Bull. Washburn College Lab. Nat. Hist. 1:207-211.


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.

Luttrell, G.R., A.A. Echelle, W.L. Fisher, and D.J. Eisenhour. 1999. Declining status of two species of the Macrhybopsis aestivalis complex (Teleostei: Cyprinidae) in the Arkansas River Basin and related effects of reservoirs as barriers to dispersal. Copeia 1999(4):981-989.

Miller, R.J., and H.W. Robison. 2004. Fishes of Oklahoma. University of Oklahoma Press, Norman. 450 pp.

Propst, D.L. 1999. Threatened and endangered fishes of New Mexico. Tech. Report No.1. New Mexico Dept. of Game and Fish., Sante Fe, NM. 84 pp.

Robison, H.W., and T.M. Buchanan. 1988. The Fishes of Arkansas. University of Arkansas Press, Fayetteville. 536 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.

Sublette, J.E., M.D. Hatch, and M. Sublette. 1990. The Fishes of New Mexico. University of New Mexico Press, Albuquerque. 393 pp.


U.S. Fish and Wildlife Service. 1994. Endangered and threatened wildlife and plants; animal candidate review for listing as endangered or threatened species; proposed rule. Federal Register 59:58982-59028.


Wilde, G.R. and B.W. Durham. 2008. Daily Survival Rates for Juveniles of Six Great Plains Cyprinid Species. Transactions of the American Fisheries Society 137:830-833.


Wilde, G. R., T. H. Bonner, and P. J. Zwank. 2001. Diet of the Arkansas River shiner and peppered chub in the Canadian River, New Mexico and Texas. Journal of Freshwater Ecology 16:403–410.


Williams, J.E., J.E. Johnson, D.A. Hendrickson, S. Contreras-Balderas, J.D. Williams, M. Navarro-Mendoza, D.E. McAllister, and J.E. Deacon. 1989. Fishes of North America endangered, threatened, or of special concern: 1989. Fisheries 14(6):2-20.