Etheostoma rupestre rupestre Gilbert and Swain 1887

Hilburn, Bryson G., Janosik, Alexis M. & Johnston, Carol E., 2023, Incipient speciation in allopatric Etheostoma rupestre (Percidae: Etheostomatinae) lineages, with the description of three new subspecies, Zootaxa 5343 (2), pp. 151-172 : 159-164

Etheostoma rupestre rupestre Gilbert and Swain 1887

Tsai’s Rock Darter

Figure 8A , Tables 1–11

Holotype. USNM 36695 , same as species lectotype.

Paratypes. USNM 188971 (17, 22–33), same as species paralectotypes .

Materials examined (nontypes).

Tombigbee River drainage: Alabama. Fayette Co., USNM 398674 , (1, 56), Harris Creek , co. rd. 53, 33.7451, -87.7593, 8 March 2010, A. M. Janosik, C. E. Johnston and T. H. Haley ; USNM 398675 , (5, 42–52) mm SL, same locality, 8 March 2010, A. M. Janosik, C. E. Johnston and T. H. Haley. Marion Co., AUM 49010 , Buttahatchee River , downstream site of Buttahatchee Dam,. 75 miles NNE of Pearces Mill (1, 45), 18 July 2007, 34.1261º, - 87.8369º; AUM 49032 , same locality, (7, 46–49), 14 July 2007, 34.1261º, -87.8369º . AUM 23708 , McConegal Creek , tributary to Bull Mountain Creek, 8.9 km NNW of Bexar Co. Road 56 (3, 32–38), 12 July 1982, 34.2663°, - 88.1667º . Sumter Co., AUM 68120 , Alamuchee Creek , at Hwy. 80, 3.8 km ENE of Cuba (13, 40–55), 11 November 2016, 32.4387º, -88.3376º. Mississippi. Lowndes Co., AUM 20642 , Tombigbee River , Buzzard Island 8.4 km S of Columbus (35, 30–40), 11 September 1979, 33.4200º, -88.4110º . AUM 3351 , unnamed creek, small tributary to Buttahatchee River 8.0 km N of Caledonia on gravel road (2, 36–43), 02 October 1968, 33.7126º, -88.3200º . Monroe Co., AUM 20489 , Tombigbee River , 6.6 km W of Amory on Highway 278 (13, 29–41), 12 September 1980, 33.9820º, -88.5190º .

Black Warrior River and North River drainage: Alabama. Jefferson Co., UAIC 3324 , Cunningham Creek , 1.6 km S of Morris (Locust Fork) U.S. Route 31 (3, 40–45), 17 August 1969, 33.7403º, -86.8119º . Tuscaloosa Co., UAIC 676 , Big Sandy Creek (1, 41), 07 February 1959, 33.0360º, -87.5870 º ; UAIC 834 , (10, 38–48), 16 February 1962, 33.0337º, -87.5821º; UAIC 409 , Gulf States Paper Company Picnic Grounds (5, 36–47), 10 August 1954, 33.0333º, -87.6083º. UAIC 804 , Big Sandy Creek and Big Sandy Spring (3, 34–42), 12 May 1961, 33.0337º, - 87.5821º . UAIC 1218 , Big Sandy Spring , 8.0 km SE of Coaling (1, 33), 20 February 1964, 33.1011º, -87.3261º; UAIC 1225 , same locality (3, 34–44), 08 March 1964, 33.0337º, -87.5821º ; UAIC 1445 , same locality (3, 35–41), 12 August 1964, 33.0337º, -87.5821º . UAIC 1243 , Carroll Creek , Highway 69, 16.1–24.1 km N of Tuscaloosa (North River) (4, 32–39), 16 April 1964, 33.29417º, -87.5697º; UAIC 3029 , Highway 69, 6.4 km N of junction of Highway 69 and U.S. Highway 82 (North River) (1, 53), 11 August 1968, 33.2942º, -87.5697º. UAIC 929 , Cottondale Creek , Keene’s Mill Road (4, 31–46), 05 November 1962, 33.1828º, -87.4425º ; UAIC 1792 , 1.6 km N of Cottondale (3, 31–33), 04 December 1965, 33.2006º, -87.4462º. UAIC 1158.03 , Hammer Creek , 6.4 km off Watermelon Road, 13.8 km N of Tuscaloosa (9, 31–48), 30 January 1963, 33.3389º, -87.5258º . UAIC 59 , Hurricane Creek , 183 m downstream of confluence of North Fork (1, 45), 26 September 1950, 33.2203º, -87.3108º . UAIC 61 , Lower Cottondale Creek (1, 36), 09 October 1956, 33.1947º, -87.4397º; UAIC 58 , 0.8 km upstream of confluence of Hurricane Creek (1, 31), 05 July 1950, 33.2057º, -87.4467º. USNM 36695 , North River , Tuscaloosa (1, 31), 1884, no lat/long. available ; UAIC 1181 , crosses Highway 69 17.7 km N of Tuscaloosa (30, 34–48), 23 September 1963, 33.3539º, -87.5572º ; UAIC 1182 , Watermelon Road , 11.3 km NE Tuscaloosa (10, 30–44), 01 October 1963, 33.2914º, -87.5128º; UAIC 1194.03 , 3.2 km upstream of Highway 69, 12.9 km N of Northport (43, 28–47), 18 November 1964, 33.3461º, -87.5786º ; UAIC 2696 , 18.0 air km N of Northport (8, 33–44), 19 September 1967, 33.3964º, -87.5797º; UAIC 3026 , unnamed dirt road 1.6 km W of Highway 69 at Macedonia Church (1, 28), 31 July 1968, 33.3528º, -87.5725º; UAIC 3522 , 12.9 air km N of junction of U.S. Highway 82 and Highway 69 (2, 40–42), 25 April 1969, 33.3528º, -87.5725º . UAIC 2576 , Rice Mine Creek , 3.2 km E of U.S. Highway 82 (3, 36–45), 21 January 1967, 33.2369º, -87.5125º . UAIC 1303 , Swampy area , Springbranch on N side of U.S. Highway 82 and Big Sandy Creek at Duncanville (2, 35–35), 22 June 1964, 33.053º, -87.4267º. UAIC 1169 , Turkey Creek , Highway 69, 22.5 km N of Tuscaloosa (2, 32–32), 13 March 1963, 33.4097º, -87.5111º ; UAIC 1172 , 4.0 km W of Highway 69, 19.3 km N of Tuscaloosa (6, 30–37), 15 March 1963, 33.3969º, -87.5533º ; UAIC 1170 , N of Tuscaloosa on Highway 69 (1, 36), 16 June 1963, 33.4097º, -87.5111º; UAIC 3182 , Highway 69 (1, 31), 16 January 1973, 33.4097º, -87.5111º; UAIC 5847.09 , Highway 69 (3, 30–41), 19 November 1979, 33.4097º, -87.5111º ; UAIC 5835.13 , Highway 69 (2, 29–30), 24 October 1979, 33.4097º, -87.5111º ; UAIC 5879.04 , Highway 69 (1, 51), 18 December 1979, 33.4097º, - 87.5111º ; UAIC 5888.10 , Highway 69 (3, 28–39), 29 January 1980, 33.3523 º, -87.5537 º ; UAIC 5897.06 , Highway 69 (5, 28–33), 21 February 1980, 33.4097, -87.5111 ; UAIC 7876.04 , 91 m downstream of Highway 69 (bridge crossing) (1, 47), 11 July 1987, 33.41º, -87.5092º ; USNM 188971 , Tuscaloosa (10, 28–31), 1884, no lat/long. available . UAIC 1198 , unnamed creek, at confluence of North River on Highway 69, 19.3 km N of Tuscaloosa (16, 31–46), 14 October 1965, 33.3556º, -87.5583º . UAIC 1150 , unnamed creek, Highway 69 at bridge crossing North River 15.3 km N of Tuscaloosa (6, 37–50), 10 January 1963, 33.3539º, -87.5572º; UAIC 1151 , bridge crossing North River off Highway 69, 15.3 km N of Tuscaloosa (5, 35–46), 08 March 1963, 33.3539º, -87.5572º. AUM 862 , unnamed creek, tributary to North River 14.8 km N of Junction 69 ( U.S. Highway 82 and Highway 69) (1, 44), 14 April 1968, 33.3840º, -87.5840º . USNM 166029 , (12, 33–46), unnamed creek, tributary to North River , 11.3 km N of New Lexington on U.S. Highway 43, 07 April 1952, 33.5740º, -87.6581º . UAIC 1647 , Black Warrior River , below dam at Tuscaloosa (1, 41), 29 June 1965, 33.2141º, -87.5756º.

Diagnosis. While individuals of Etheostoma . r. rupestre cannot be morphologically distinguished from other subspecies due to overlap in all traits measured, entire populations can be diagnosed by the following tendencies: populations of E. r. rupestre have modally five scales above the lateral line (as opposed to six in both E. r. piersoni and E. r. uphapeense ) ( Table 2 ), tend to have low numbers of lateral line scales (usually 45–59 vs. 49–63 in other subspecies) ( Table 1 ), tend to have wide ranges of nape squamation (naked to fully scaled in E. r. rupestre vs.>40% in other subspecies) ( Table 7 ), and by having few lateral blotches along the midline that may often be diffuse (3–8 distinct blotches in E. r. rupestre vs. 5–9 in E. r. piersoni and 7–9 in E. r. uphapeense ) ( Table 9 ).

Description. Populations of Etheostoma r. rupestre possess the following traits: body ventrally flattened, lateral line scales 45–59 in>99% of specimens (modally 49–53) ( Table 1 ), scale rows above the lateral line 4–7 (modally 5) ( Table 2 ), scales below lateral line 6–12 (modally 8–9) ( Table 3 ), scales around the caudal peduncle 16–23 (modally 18–20) ( Table 4), dorsal-fin spines IX–XII (modally XI) ( Table 5 ), dorsal-fin rays 9–13 (modally 11–12) ( Table 6), nape squamation 0–100% (naked to fully scaled) (mean 75–80% squamation) ( Table 7 ), 10–90% belly squamation (mean 44–58%) ( Table 8), lateral blotches tend towards being few and diffuse (3–8 distinct blotches, mean 6.4) ( Table 9 ), distance between blotches 3.5–7.5% of SL (mean 4.8%), lateral blotch width 4.2–6.6% of SL (mean 5.5%), dorsal saddle width 5.8–9.1% of SL (mean 8.0) ( Table 10 ), distal band in first dorsal fin 21.4–48.2% of fin depth (mean 38.3%), total first dorsal pigment 59.0–74.6% of fin depth (mean 66.9) ( Table 11 ), nuptial coloration ranging from light blue to dark green.

Distribution. The range of Etheostoma . r. rupestre extends from the lower Tombigbee watershed in Alabama to the upper Tombigbee watershed of Mississippi and the Black Warrior watershed ( Fig. 2 ). Etheostoma r. rupestre is disjunct from other E. rupestre subspecies.

Etymology. As species. The common name honors Chu-fa Tsai, who has contributed to the understanding of morphological divergence in E. rupestre .

Figures

FIGURE 2. Locations of museum material examined that possessed lat/long coordinates. Dark grey background shading indicates the boundaries of the Mobile Basin and colored shading indicates geographic ranges of each subspecies within the Mobile Basin to which Etheostoma rupestre is endemic. Populations delimited as E. r. rupestre in the current study but for which some taxonomic uncertainty remains are also indicated.

FIGURE 8. Male pigmentation of A) Etheostoma rupestre rupestre—47 mm SL, Cottondale Creek, County Road 32, Tuscaloosa, Alabama (photo by K. Boone), B) E. r. piersoni—61 mm SL, Chilatchee Creek, Highway 5, 1 mile north of Alberta, Alabama (photo by K. Boone), and C) E. r. uphapeense—45 mm SL, Opintlocco Creek, County Highway 20, ~3 miles East of Tuskegee, Alabama (Photo by B. Hilburn).