bluehead shiner Pteronotropis hubbsi

Pteronotropis hubbsi

bluehead shiner

Type Locality

Locust Bayou, tributary to Ouachita River, 1 km west of Locust Bayou at State Hwy. 4 bridge, Calhoun County, Arkansas (Bailey and Robison 1978).

Etymology/Derivation of Scientific Name

Ptero – winged, referring to Notropis species with enlarged dorsal fin on breeding males; hubbsi – in honor of Carl L. Hubbs, Notropis expert (Scharpf 2005).

Synonymy

Notropis hubbsi Bailey and Robison 1978:3-13; Gilbert 1980:273.

Characters

Maximum size: 60 mm (2.36 in) TL (Page and Burr 1991).

Coloration: Distinctive, broad black midlateral stripe extending from chin through eye across the opercle backward to the caudal base where it terminates in a deep, darker basicaudal spot extending a short distance onto the caudal rays; body dusky above; lower surface of head and belly white; chin distinctly black. Breeding males and females with reddish orange dorsolateral surface, especially just above the lateral stripe. Rays of basal half to three-fifths of caudal fin and basal half of dorsal fin reddish orange. Males with olive-yellow on membranes but not rays of middle of anal fin, excluding basal fifth and distal fifth. Males have large, dark dorsal fin with trace of orange on dorsal rays. Larger males with iridescent greenish hue on dorsal fin membranes from just proximal of middle of fin almost to its distal margin. Pelvic and anal fins mostly with a blue-green wash. Brilliant iridescent blue on top of head from between nostrils to occiput (Bailey and Robison 1978; Robison and Buchanan 1988). During agonistic behavior, males developed a vertical bar pattern (10-12 bars) on their sides with the more dominant male having noticeably darker bars (Fletcher and Burr 1992; Ranvestel and Burr 2004).

Pharyngeal teeth count: 1,4-4,1 or 2,4-4,2.

Counts: 40 or fewer scales in lateral line; 24 or fewer predorsal scales; usually 9 to 12 anal fin soft rays; fewer than 10 dorsal fin soft rays (Hubbs et al. 2008).

Mouth position: Terminal and oblique (Hubbs et al. 2008).

Body shape: Body deep and compressed (Bailey and Robison 1978). .

Morphology: 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 and not separated by a definite groove from the lower lip. Origin of dorsal fin behind insertion of pelvic fin; dorsal origin nearer base of caudal fin than tip of snout (Hubbs et al. 2008). Intestinal canal short, forming a simple S-shaped loop (Hubbs et al. 2008).

Distribution (Native and Introduced)

U.S. distribution: Found sporadically in Arkansas and Louisiana; found in Caddo Lake, Texas (Hubbs et al. 2008). Red, Ouachita and Atchafalaya River systems west of Mississippi River (Texas, Oklahoma, Arkansas, Louisiana); and Wolf Lake (Illinois; Ranvestel and Burr 2004; Scharpf 2005).

Texas distribution: Caddo Lake (Hubbs et al. 2008).

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

State Threatened (Texas; Hubbs et al. 2008). Listed as Vulnerable by the American Fisheries Society; category of threat: present or threatened destruction, modification, or reduction of habitat or range (Jelks et al. 2008). Vulnerable (Scharpf 2005); Endangered status in Illinois (but believed to be extirpated; Ranvestel and Burr 2004); Threatened status in Texas; Special Concern status in Arkansas and Oklahoma (Scharpf 2005). According to Ranvestel and Burr (2004), no states were currently employing any activities specifically targeted at conserving Pteronotropis hubbsi populations. Vulnerable (Warren et al. 2000) in the southern United States. In the 1990s, an effort to reestablish a viable P. hubbsi population in the state of Illinois was apparently unsuccessful (Ranvestel and Burr 2004). Gilbert (1980) noted that this species is regarded as very rare, perhaps a result in part perhaps from inaccessibility of preferred habitat to conventional collecting techniques.

Habitat Associations

Macrohabitat: Small to medium-sized streams and oxbow lakes (Bailey and Robison 1978; Robison and Buchanan 1988; Gilbert 1980).

Mesohabitat: Quiet backwater areas of small to medium-sized, sluggish streams and oxbow lakes having mud or mud-sand substrate; water typically tannin-stained, and heavy growth of submergent or semi-emergent vegetation often present (Bailey and Robison 1978; Robison and Buchanan 1988; Gilbert 1980). This species schools in backwater and side areas away from substantial current and seems to remain in mid-water, just outside of vegetation, darting into it for protection when disturbed (Bailey and Robison 1978; Robison and Buchanan 1988). In Oklahoma, individuals were collected from bar pits (unconnected to the Little River at time of capture), described as swampy areas 1.0-1.5 m deep, with a silt and detritus substrate; fish were immediately next to emergent and floating vegetation (Lemmons et al. 1997).

Biology

Spawning season: Species probably spawns multiple clutches during May-July spawning season (Fletcher and Burr 1992; Taylor and Norris 1992; Ranvestel and Burr 2004). Tuberculate males have been taken from early to mid-May to June; young-of-the-year collected in early June (Robison and Buchanan 1988). In Illinois, spawning occurs from late May to July (Burr and Warren 1986).

Spawning habitat: Nest associate (Mayden and Simons 2002); known to spawn over centrarchid nests (Lepomis gulosus, the warmouth; Fletcher and Burr 1992). At Chemin-a-haut Bayou, Louisiana, nests were located in diverging roots of trunks of bald cypress trees; very little underwater vegetation present, aside from moss growing on tree trunks; floors of nest cavities differed from surrounding substrate (mixed silt and detritus) in that the nest floors were covered with large, deciduous leaves, cypress fronds, and pine needles, and were silt-free (apparently swept clean by one or more nest associates; Fletcher and Burr 1992; Ranvestel and Burr 2004).

Spawning behavior: Robison and Buchanan (1988) reported the presence of two classes of males during studies at the type locality, during May-July; “flag males” (having large dorsal fins) actually spawned while younger “non-flag males” were not directly engaged in spawning. Two groups of males were also observed during the spawning season in a population in Oklahoma (Taylor and Norris 1992), and in a population in Louisiana (pers. comm.., D. Fletcher and B. Burr in: Taylor and Norris 1992).

Males display two phases of development termed “initial males” and “terminal males”: “initial males” began transformation into “terminal males” during the second year of life (about 41 mm SL); terminal males were dominant individuals in a school (Fletcher and Burr 1992; Ranvestal and Burr 2004). “Terminal males” were longer than “initial males” and females, and had greatly expanded dorsal, anal, and pelvic fins; blue coloration on top of the heads of small (42-45 mm SL) terminal males was faded and was absent on the largest (= 45 mm SL) individuals compared to the iridescent powder blue colored heads of initial males and females; “terminal males were deeper bodied and more “slab-sided” than “initial males” and females; all but largest initial males (> 38 mm SL) were also distinguished by iridescent blue coloration on pectoral and pelvic fins, while females lacked this coloration on fins; after peak of breeding season, both “initial males and females lost the blue on their heads (Fletcher and Burr 1992; Ranvestal and Burr 2004).

In an act thought to represent pre-spawning behavior, males (in both phases of development) were observed to chase females in both ponds and aquaria; males swam beside and slightly above females with fins erect and heads downward, pushing female toward the substrate (Fletcher and Burr 1992; Ranvestel and Burr 2004). While being transported in a container, two males were observed to align themselves on each side of a female, vibrating rapidly while their dorsal fins curved over her back; no development occurred in released eggs in this apparently unsuccessful spawning attempt (probably due to the unnatural conditions; Fletcher and Burr 1992; Ranvestel and Burr 2004).

“Terminal males” territorial and display agonistic behavior when defending nests (Fletcher and Burr 1992; Ranvestel and Burr 2004). “Initial males” (= secondary males) not territorial and may “sneak” into territories of “terminal males” and spawn (Fletcher and Burr 1992).

Fecundity: A 46.6 mm female from Illinois contained 781 mature ova which averaged 0.8 mm in diameter (Burr and Warren 1986). In Oklahoma, clutch size ranged from 172-1,129 mature ova for 26 females ranging from 34.5-49.5 mm SL (Taylor and Norris 1992). Mature follicles yellow-orange, and ranged from 0.70-1.20 mm in diameter (Burr and Warren 1986; Fletcher and Burr 1992; Taylor and Norris 1992), and were adhesive upon release into water (Fletcher and Burr 1992; Ranvestel and Burr 2004).

Age/size at maturation: Females reported to apparently be sexually mature at one year of age, between 36-40 mm SL (Fletcher and Burr 1992; Ranvestel and Burr 2004). In Illinois, females were sexually mature at 1 year (47 mm SL; Burr and Warren 1986).

Migration: Robison and Buchanan (1988) reported evidence strongly supporting the probability of a migratory pattern in Ouachita drainage streams.

Growth and Population structure: Males of this species have two phases of post-juvenile development; these phases differing in overall body size, coloration, relative fin sizes, and behavior: larger, and socially dominant “terminal males” are much less abundant (1:6) in breeding schools than smaller, less aggressive, and more brightly colored secondary males (Fletcher and Burr 1992).

Longevity: Usually less than 2 years (Burr and Warren 1986; Fletcher and Burr 1992; Taylor and Norris 1992; Ranvestel and Burr 2004). Taylor and Norris (1992) reported that most individuals in an Oklahoma population died during their second summer at age one; however, evidence suggested the potential for survival to age two. Maximum lifespan apparently 2 years; older 2 year males probably die after spawning (Robison and Buchanan 1988; Fletcher and Burr 1992). In aquaria, one male lived at least three years (Fletcher and Burr 1992; Ranvestel and Burr 2004).

Food habits: Feeding primarily in the water column, but individuals picked items off of vegetation and the water surface; diverse diet dominated by microcrustaceans; common adult food items were cladocera, chironomid larvae, and adult copepods; juveniles ingested cladocera, copepod nauplii and adults, chironomid larvae, rotifers, nematodes, and a variety of diatoms, and green filamentous algae; traces of seeds, bryzoans, water mites, and a variety of other insects were also found in adult and juvenile guts; diets of males and females did not differ (Fletcher and Burr 1992; Ranvestel and Burr 2004). Gut content analysis of fish reared in a southern Illinois pond showed that guts of most individuals empty during the winter months (Ranvestel and Burr 2004).

Phylogeny and morphologically similar fishes

Sister-group relationship between Pteronotropis hubbsi and P. welaka (Simons et al. 2000). See Fletcher and Burr (1992) for description and illustration of larvae; Fletcher and Burr (1992) noted that P. hubbsi larvae could be distinguished from other syntopic larval cyprinids by a distinctive caudal spot, and combinations of other pigment and morphological characters.

Host Records

Report of individuals heavily infested with Lernaea cyprinacea, a copepod parasite; infected with a Trichodina-like ciliate; and diseased due to bacterium Flexibacter columnaris (Ranvestel and Burr 2004).

Commercial or Environmental Importance

In Arkansas, this species considered to be of special concern due to a rather restricted distribution within the state and continued environmental degradation of lowland streams of the Ouachita River system, e.g., gravel removal at the type locality (Robison and Buchanan 1988). Ranvestel and Burr (2004) listed categories of threats to this species: destruction, modification, or curtailment of habitat or range; overutilization for commercial, recreational, scientific or educational purposes; predation; parasites and diseases. In Louisiana, P. hubbsi larvae were eaten by two species of pike (Esox), largemouth bass (Micropterus salmoides; Fletcher and Burr 1992).

References

Bailey, R.M., and H.W. Robison. 1978. Notropis hubbsi, a new cyprinid fish from the Mississippi River basin with comments on Notropis welaka. Occas. Pap. Mus. Zool. Univ. Mich. 683:1-21.

Burr, B.M., and M. L. Warren. 1986. Status of the bluehead shiner (Notropis hubbsi) in Illinois. Trans. Illinois Acad. Sci.. 79:129-136.

Fletcher, D.E., and B.M. Burr. 1992. Reproductive biology, larval description, and diet of the North American bluehead shiner, Pteronotropis hubbsi (Cypriniformes: Cyprinidae), with comments on conservation status. Ichthyological Exploration of Freshwaters 3:193-218.

Gilbert, C.R. 1980. Notropis hubbsi (Bailey and Robison), Bluehead shiner. pp. 273 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., 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, 2^nd edition 43(4):1-87.

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.

Lemmons, R.P., M.J. Hood, and L.G. Hill. 1997. New Oklahoma localities for shortnose gar (Lepisosteus platostomus), largescale stoneroller (Campostoma oligolepis), and bluehead shiner (Pteronotropis hubbsi). Proc. Okla. Acad. Sci. 77:125-126.

Mayden, R.L., and A.M. Simons. 2002. Crevice spawning behavior in Dionda dichroma, with comments on the evolution of spawning modes in North American shiners (Teleostei: Cyprinidae). Reviews in Fish Biology and Fisheries 12:327-337.

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.

Ranvestel, A.W., and B.M. Burr. 2004. Conservation assessment for bluehead shiner (Pteronotropis hubbsi). American Currents 30(1) [Winter]:17-25.

Robison, H.W., and T.M. Buchanan. 1988. Fishes of Arkansas. The 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.

Simons, A.M., K.E. Knott, and R.L. Mayden. 2000. Assessment of the minnow genus Pteronotropis (Teleostei: Cyprinidae). Copeia 2000(4):1068-1075.

Taylor, C.M., and S.M. Norris. 1992. Notes on the reproductive cycle of Notropis hubbsi (bluehead shiner) in southeastern Oklahoma. The Southwestern Naturalist 37(1):89-92.

Warren, M.L., Jr., B.M. Burr, S.J. Walsh, H.L. Bart, Jr., R.C. Cashner, D.A. Etnier, B.J. Freeman, B.R. Kuhajda, R.L. Mayden, H.W. Robison, S.T. Ross, and W.C. Starnes. 2000. Diversity, Distribution, and Conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.