Shoal Chub

description

Description. Characters listed in the diagnosis are not repeated here, unless additional clarification is required. Variation in meristic characters is presented in Table 1. Dorsal-fin rays 8; anal-fin rays usually 8 (range 7 – 9); pectoral-fin rays usually 15 (range 14 – 16); pelvic-fin rays usually 8 (occasionally 7); lateral-line scales modally 37 (range 35 – 39); predorsal scales irregularly distributed and poorly defined, numbering 15 – 17 (range 14 – 19); body-circumferential scale rows above and between lateral lines usually 11 (range 9 – 12); body-circumferential scale rows below and between lateral lines usually 12 – 13 (range 11 – 14), the scales occasionally incomplete or absent from middle of belly; total caudalpeduncle scale rows uniformly 12 (five scale rows above and below lateral lines on each side of caudal peduncle); total vertebrae 37 – 38 (range 36 – 39); scales present and well developed in area between pelvic and anal fins; anal and dorsal fins usually angular and slightly falcate, the anteriormost rays (when depressed) extending about same distance posteriorly as posteriormost rays; head somewhat rounded and moderately flattened ventrally; mouth inferior and

Morphological and genetic evolution in eastern populations of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae), with the descriptions of four new species

description

Despite its broad geographic range and demonstrated morphological variability, the nomenclature of Macrhybopsis hyostoma, as presently recognized, has remained remarkably stable, with no junior synonyms as yet having been identified (Gilbert 1998: 28). A list of non-type material examined during the present study, comprising 43 lots and 409 total specimens, appears in Appendix 1. Status of Hybopsis montanus. The identity of Hybopsis montanus is uncertain (Gilbert 1998: 116; Eisenhour 2004: 31). Meek (1885: 526 – 527) indicated the description to have been based on three specimens, supposedly from the “ upper Missouri River basin, ” having 4 - 4 pharyngeal teeth (slightly hooked), a pair of well developed maxillary barbels, 37 lateral-line scales, 14 predorsal scales, and six anal rays (last character obviously erroneous), a slender and elongated body, body silvery (without spots), and dorsal fin situated directly above pelvic fins. Other than anal-ray count and lack of spots on the body, this is an accurate description of most populations of Macrhybopsis hyostoma, which does not occur in the upper Missouri River basin or any closely adjacent area (Wallace 1980: 180). The three spec

Morphological and genetic evolution in eastern populations of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae), with the descriptions of four new species

description

Macrhybopsis aestivalis hyostoma. — Boschung & Mayden 2004: 108 – 109, pl. 20 D (general account; illustration; distribution in Alabama).

Morphological and genetic evolution in eastern populations of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae), with the descriptions of four new species

diagnosis

Diagnosis. The following diagnosis is based solely on populations occurring east of the Mississippi River (comprising a total of 43 lots and 409 specimens), the geographic limits of which extend from the Tennessee River drainage north to the Ohio River drainage (Fig. 2, Appendix 1). Those from the Ohio River drainage include material from the states of West Virginia, Kentucky, Ohio and Indiana west to the Wabash River system, which (in its lower reaches) forms the boundary between Indiana and Illinois. An expanded diagnosis of Macrhybopsis hyostoma appears in Eisenhour’s (2004: 31 – 34) study, which is largely confined to populations west of the Mississippi River. A member of the Macrhybopsis aestivalis complex, as defined in the generic diagnosis. Characterized by a single pair of moderately long maxillary barbels, 4 - 4 pharyngeal teeth, eight anal rays, anal opening closer to analfin origin than pelvic-fin origin (ca. 70 percent of intervening distance), and prominent dark melanophores on upper two-thirds of body (Fig. 1 A) (also see Smith 1979: 75; Trautman 1981: fig. 47; Boschung & Mayden 2004: pl. 20 D). Among other eastern species of the complex, the first four characters ar

Morphological and genetic evolution in eastern populations of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae), with the descriptions of four new species