14 Bulletin 30 NOVEMBER 1, 2012Figure 6. <strong>Etheostoma</strong> jessiae (Jordan and Brayton, 1878). Coal Creek along Tennessee Hwy 116, 2.1 air km SW LakeCity, Morgan Co., Tennessee, 12 April 1992. UAIC 10380.01; male, 53 mm SL. Drawing by Joseph R. Tomelleri (americanfishes.com).Copyright by Joseph R. Tomelleri. Used <strong>with</strong> permission.extending from dorsal to ventral margin <strong>of</strong> caudal fin.Frenum usually present. Lateral line incomplete, unporedscales modally 8. Cheek partially scaled. Palatineteeth present. Dorsal fin spines modally 12–13; dorsal s<strong>of</strong>trays modally 12. Anal fin s<strong>of</strong>t rays modally 9. Pectoral finrays modally 14–15. Principal caudal fin rays modally 15.Caudal peduncle scales modally 17–18. Preoperculomandibularcanal pores modally 10.Description.—Males average larger than females; largestmale 64.6 mm SL, largest female 56.1 mm SL. Sexesexhibit significant dimorphism (P
Layman & Mayden Morphological Diversity and Phylogenetics <strong>of</strong> the Darter subgenus Doration (<strong>Percidae</strong>: <strong>Etheostoma</strong>) 15lum, preoperculum, and suborbital bar; no blue on midgulararea. Lateral belly yellow; medial belly gray. Basecolor <strong>of</strong> upper body straw to olivaceous or gray. Sides <strong>with</strong>usually 9–10 (8–11) vertical iridescent blue bars. Scalesbetween lateral bars outlined in powder blue. Sides <strong>with</strong>orange markings along scale edges between lateral barsand extending to dorsum; orange becoming brighterposteriorly on caudal peduncle. Dorsolateral area also<strong>with</strong> many small dark brown and blue markings. Dorsum<strong>with</strong> 6 prominent dark brown or gray hourglass-shapedsaddles. Johnson (1987) provides a color plate <strong>of</strong> a livebreeding male photographed by W. N. Roston. Colorplates are also provided by Page (1983) and Kuehne andBarbour (1983).Tuberculation.—Pelvic and anal fin tuberculation primarilyconsists <strong>of</strong> epidermal ridges, which are <strong>of</strong>ten welldeveloped. Pelvic rays 3–5 and last few anal rays occasionally<strong>with</strong> broken ridges and only rarely <strong>with</strong> a few individualdistinct tubercles. As also noted by Collette (1965),ventral body scale tubercles are <strong>of</strong>ten well developed. Atmaximum development, tubercles may occur on 2 midventralscale rows behind pelvic fin bases, 11 midventralscale rows at mid-belly, 9 midventral scale rows at anus,1–4 scale rows above anal fin, and 5–6 midventral scalerows on caudal peduncle. Well-developed tubercles havebeen noted on specimens collected from 3 February (ElkRiver, Grundy County, Tennessee) to 9 May (Lick Creek,Greene County, Tennessee), <strong>with</strong> weak tubercles detectedas early as 26 January (Spring Creek, Polk County, Tennessee)and as late as 21 May (Factory Creek, LawrenceCounty, Tennessee).Variation.—The most notable morphological characterexhibiting geographic variation is the premaxillaryfrenum. Eighty-eight percent <strong>of</strong> all specimens examined(n = 575) possessed a narrow to broad frenum. In the upperTennessee drainage, including the Clinch River systemboth above and below Norris Dam, this proportion is86–98% (n = 405). In contrast, 76.5% <strong>of</strong> specimens (n =170) from the lower and middle Tennessee drainage, includingLittle Bear Creek, have a usually narrow to moderatefrenum. Howell (1968; 1980a) treated specimensfrom Little Bear Creek as intergrades or hybrids betweenE. jessiae and E. stigmaeum (from adjacent Bear Creek) becauseonly six <strong>of</strong> 12 available specimens (50%) possesseda frenum. However, examination <strong>of</strong> 49 specimens fromLittle Bear Creek found that 69% <strong>of</strong> specimens possessa frenum. A few other populations <strong>of</strong> E. jessiae in themiddle Tennessee drainage exhibit similar frequencies<strong>of</strong> individuals possessing a frenum but there is no cleargeographic cline suggestive <strong>of</strong> a hybrid or intergradezone. Moving up the Tennessee River from Bear Creek,proportions <strong>of</strong> specimens <strong>with</strong> a frenum are 100% in CypressCreek (n = 10), 73% in Shoal Creek (n = 26), 100%in Bluewater Creek (n = 10), 88% in Elk River (n = 16),65% in Paint Rock River (n = 23), and 73% in SequatchieRiver (n = 26). An alternative explanation to Howell’s(1968) hypothesis <strong>of</strong> hybridization, one that is supportedby additional meristic, breeding color, and allozymic datadiscussed below under “CONTACT ZONES,” is that thepolymorphic condition <strong>of</strong> the frenum has been retainedfrom the ancestor <strong>of</strong> E. jessiae.Specimens <strong>of</strong> E. jessiae from the French Broad Riversystem have higher scale counts than any other populationsexamined. Mean counts (and ranges) for 60 specimenswere 53.4 (46–60) lateral scales, 15.5 (13–19) transversescales, 8.1 (7–10) scales below the lateral line, 6.2(5–8) scales above the lateral line, and 18.9 (16–22) caudalpeduncle scales (compare <strong>with</strong> Tables 1, 3, 4, and 5).This observation led to the determination that the singlerecord <strong>of</strong> E. jessiae from Stones River <strong>of</strong> the Cumberlanddrainage (CU 46558), thought by Howell (1980a) to representan undescribed species similar to E. jessiae, wasbased erroneously on specimens <strong>of</strong> E. jessiae from LittlePigeon River <strong>of</strong> the French Broad River system (Layman,1994). The largest specimen <strong>of</strong> E. jessiae is also from theFrench Broad River system: a 64.6–mm SL male from theNolichucky River system (UT 91.1209). Elsewhere maximumadult size is about 57 mm SL.Modal pectoral fin ray counts in E. jessiae are 15throughout the Tennessee drainage, <strong>with</strong> the exception<strong>of</strong> Clinch River populations, where the mode is 14. Thisshift may due to introgressive hybridization <strong>with</strong> E. meadiae(Etnier and Starnes, 1994), which also has a mode <strong>of</strong> 14and occurs farther upstream in the Clinch River system(see “CONTACT ZONES” below).Distribution.—<strong>Etheostoma</strong> jessiae is endemic to the TennesseeRiver Drainage, occurring from White Oak Creek,Houston and Humphreys counties, Tennessee, upstream,but not including Duck River, through Alabama and Tennesseeinto the French Broad River in North Carolinaand the Holston River in Virginia (Fig. 5). In the BearCreek system <strong>of</strong> Alabama, E. jessiae occurs only in the LittleBear Creek tributary system and is parapatric <strong>with</strong> E.stigmaeum, which is restricted to upper Bear Creek and itstributaries; the two species have not been taken together.The historic range <strong>of</strong> E. jessiae extends upstream in theClinch and lower Powell rivers to at least three tributaries<strong>of</strong> Norris Reservoir, including (Fig. 7): Cove Creek,downstream <strong>of</strong> the Clinch and Powell rivers confluence;a “pond opposite Doak’s Dam” (UMMZ 103591), presumablyin the Davis Creek system <strong>of</strong> the lower Powell River(possibly in the Davis Creek embayment); and Big SycamoreCreek, a tributary <strong>of</strong> the Clinch River in the upperend <strong>of</strong> the reservoir. The species was last collected in Coveand Davis creeks in 1936–37, shortly after completion <strong>of</strong>Norris Dam, and may no longer occur there due to impoundment<strong>of</strong> habitat. <strong>Etheostoma</strong> jessiae is parapatric <strong>with</strong>E. meadiae, which occurs upstream <strong>of</strong> Norris Reservoir inthe Clinch and Powell rivers. Specimens from PossumCreek (CU 68500) and Cove Creek (UMMZ 130756) <strong>of</strong>North Fork Holston River, Scott County, Virginia, wereverified as E. jessiae; Jenkins and Burkhead (1994) had
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