Macrhybopsis aestivalis

Gilbert, Carter R., Mayden, Richard L. & Powers, Steven L., 2017, Morphological and genetic evolution in eastern populations of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae), with the descriptions of four new species, Zootaxa 4247 (5), pp. 501-555 : 522

Key to species of Macrhybopsis aestivalis complex east of Mississippi River

1a. Anal-fin rays usually 7; two pairs of maxillary barbels; dorsal-fin origin directly above pelvic-fin origin; pharyngeal teeth always 4-4; anal opening midway between pelvic and anal-fin origins; body essentially pallid , the melanophores tiny and usually not readily visible; belly scaleless anterior to pelvic fins; pectoral-fin rays in males long and pointed, the outer rays notably longer than innermost rays (fins generally shorter in females) and often extending past pelvic-fin origin; average body size smaller, rarely reaching 50 mm SL, with great majority of specimens (all but six of 667 specimens examined) under 46 mm SL................................................................................... Macrhybopsis pallida Eastern Gulf slope drainages of western Florida and southeastern Alabama, including Escambia, Blackwater Bay, and Choctawhatchee river drainages

1b. Anal-fin rays usually 8; one pair of maxillary barbels; dorsal-fin origin either directly above or distinctly behind pelvic-fin origin; pharyngeal teeth either 4-4, 1,4-4,1, or some combination thereof; anal opening either midway between pelvic and anal-fin origins or distinctly closer to anal-fin origin; body pigmentation variable, the body rarely if ever pallid and melanophores normally prominent and readily visible; belly squamation variable, ranging from scaleless to an obvious bridge of scales across belly immediately anterior to pelvic-fin origin; pectoral fins in males variable in length (fins generally shorter in females), the outermost rays sometimes distinctly longer than inner rays and the fins more pointed and reaching pelvic-fin origin, at other times the outer rays not notably longer and the fin rounded, falling well short of pelvic-fin origin; average body size larger, occasionally reaching 60 mm SL and often exceeding 50 mm SL................................................2

2a. Anal opening midway between origins of pelvic and anal fins; number of scale rows above and between lateral lines on either side of body usually 9 or 10, rarely 11; pharyngeal teeth usually 1,4-4,1, occasionally with tooth absent from one or (very rarely) both lesser rows; dorsal-fin origin distinctly posterior to hypothetical vertical line extending upward from pelvic-fin origin ( Fig. 1 C); belly immediately anterior to pelvic fins usually heavily scaled and forming a bridge of two to five scales across belly; body pigmentation comprising a combination of numerous large and small melanophores, these often coalesced along mid-side of body to form a poorly defined lateral stripe; pectoral fins short and broadly rounded at tip, seldom if ever extending posteriorly to pelvic-fin origin; snout shorter and blunter, the preorbital length either less, or equal to, postorbital length; total vertebrae usually 38 or 39 (counts averaging higher in headwater areas of Georgia and Tennessee)................................................................................................ Macrhybopsis etnieri Mobile Bay basin; restricted to areas above Fall Line in Cahaba, Tallapoosa and Coosa river systems in Alabama, Georgia and Tennessee; occurs sympatrically with Macrhybopsis boschungi (with no evidence of hybridization) over a 40-km section of middle Cahaba River in Fall Line region of Alabama

Figures

FIGURE 1. Species of Macrhybopsis aestivalis species complex from eastern North America. A) Macrhybopsis hyostoma, UAIC 11060.03, Female, 34 mm SL, Alabama, Limestone County, Elk River, 28 September 1994. B) Macrhybopsis boschungi, UAIC 10845.03, Female, 50 mm SL, Alabama, Dallas County, Cahaba River, 12 July 1993. C) Macrhybopsis etnieri, UAIC 11053.01, Female, 44 mm SL, Alabama, Bibb County, Cahaba River, 24 June 1994. D) Macrhybopsis pallida, UAIC 10855.04, Female, 36 mm SL, Alabama, Escambia County, Conecuh River, 15 July 1993. E) Macrhybopsis tomellerii, UAIC 11364.03, Female, 51 mm SL, Mississippi, Covington County, Pascagoula River drainage, 18 February 1994.