Micropterus coosae Hubbs and Bailey 1940

Baker, Winston H., Blanton, Rebecca E. & Johnston, Carol E., 2013, Diversity within the Redeye Bass, Micropterus coosae (Perciformes: Centrarchidae) species group, with descriptions of four new species, Zootaxa 3635 (4), pp. 379-401 : 390-391

Micropterus coosae Hubbs and Bailey 1940

Redeye Bass

Figs. 1 & 2 A–C

Holotype. Coosa River drainage. Alabama. Etowah Co., UMMZ 97729, 106.5 mm SL, Fisher Creek, tributary to Big Will’s Creek, on old highway between Attalla and Boaz, 3 July 1928.

Paratypes. Alabama. Etowah Co., UMMZ 96762 (2, 68–79), Fisher Creek, trib., Big Will’s Creek, old Hwy between Boaz and Attala, 3 July 1928. Georgia. Floyd Co., UMMZ 88205 (4, 23–84), trib., Coosa River, 8.0 km W Coosa, 1 September 1929.

Additional Materials (nontypes), current study.

Coosa River drainage

Alabama. Cherokee Co., (4, 174–215), Little River at Little River State Park, CR 275, 19 September 1998; Clay Co., (1, 177), Hatchet Creek, CR 4, 6 August 1998; (1, 169), 9 August 1999; AUM 51097 (1, 160), 13 March 2009; AUM 51083, 51092, 51094 (3, 165–229), 17 April 2009; AUM 58726 (1, 76), 18 June 2010; (2, 155–176), Hatchet Creek, US Hwy 280, 16 August 1998; AUM 51096, 51093 (2, 146–167); Coosa Co., Weogufka Creek, 11.3 km SW of Weogufka, 2 April, 2009; AUM 51084, 51091 (3, 157–238), 23 April, 2009; AUM 51086, 51095 (2, 182–204), 29 April 2009; (1, 247), 30 June 2009; Elmore Co., AUM 51081 (1, 156), Weoka Creek, at CR 429, 23 April 2009. Talladega Co., AUM 51085, 51098 (2, 214–247), Choccolocco Creek, 1.6 km upstream from CR 326 bridge, 5 November 2008; AUM 51082 (5, 168–252), Cheaha Creek, CR 93, 9.6 km N Talladega, 9 August 1998; (1, 167), 17 November 1998; (1, 225), 26 November 2008; AUM 51090 (1, 235), 4 December, 2008; (3,137–205), Talladega Creek, St. Hwy 77 at Waldo, 8 August 1998; Georgia. Gilmer Co., AUM 58727 (1, 129), Mountaintown Creek, jct. St. Hwy 282/76, 20 June 2010; AUM 58728 (1, 103), Tails Creek, jct. St. Hwy 282/76, 20 June 2010.

Diagnosis. A species of Micropterus that differs from all other members of the M. coosae species group by having red on the distal one-half of second-dorsal, caudal, and anal fins, and entire length of pectoral-fin rays (vs. green, yellow-green, or orange on smaller portions of fins in other species) and midline row of blotches partial to lacking, typically with 6 or fewer anterior vertical blotches with the remainder too diffuse to recognize as blotches or spots (in 76% of individuals; remaining 24% with midline row of blotches extending total body length, having 10–13 blotches; Table 9, Figs. 1 & 2 A–C ). The species is further distinguished from M. tallapoosae and M. chattahoochae by a combination of the following characters: smaller scales (2.6 vs. 2.9% SL); higher scale counts, including lateral-line scales (mode 70 vs. 65 or 66; range 68–73 in 83.8% vs. 61–67 in 77.2%), and scale rows around caudal peduncle (mode = 30 vs. 29; range 30–32 in 80.0% vs. 26–29 in 94.1%). The species is further distinguished from M. warriorensis by having a tooth patch (present in 97% vs. absent in 82.9%); from M. tallapoosae , M. warriorensis , M. cahabae , M. chattahoochae , and M. cf. coosae (Savannah River) by a narrower postfrontal width (11.0% vs. 11.2% SL or more); and from M. cahabae by the presence of more pronounced white tips on the caudal fin.

Description. Micropterus coosae is a small species of bass that attains 360 mm SL and 0.7 kg. Values for diagnostic morphological characters are summarized in Tables 2–9, and general body shape, pigmentation, and pattern are illustrated in Figures 1 and 2 A–C .

Narrow head, postfrontal width 10.5–11.4% (11.0%), scale width 2.2–3.0% (2.6%), tongue tooth patch size 0–4.0 mm (mode = 2.0); lateral-line scales 66–73 (70), scales above lateral line 6–9 (7), scales below lateral line 10–13 (11), scales around caudal peduncle 28–32 (30); anterior dorsal-fin spines 9, posterior dorsal-fin spines 1, anal-fin spines 3; pectoral-fin rays 15–17 (16), posterior dorsal-fin rays 12–14 (12), anal-fin rays 10–11 (10), caudal-fin rays 17; pyloric caeca unbranched.

Body pigmentation above midline medium green often with bronze shimmer; below body midline white, usually 0–6 vertical black blotches along midline of body (76%) anteriorly, followed by diffuse blotches or spots posteriorly; a few individuals with 10–13 vertical blotches along length of body. The dorso-lateral row of spots is often dispersed and recognizable only as numerous dots; otherwise 5-9 spots (mean 8).

Anterior dorsal-fin spines dark green, often tipped with white, membranes translucent medium green. Posterior dorsal-fin rays red with anterior 5 or 6 rays tipped in white; basal portions of membranes translucent green; distal one-half red except posterior three or four membranes transparent. Caudal-fin rays medium to dark green along basal two-thirds and red on distal portion; membranes translucent medium green along basal two-thirds and distally translucent red; narrow white border present along superior and inferior margins. Anal-fin rays dark green along basal one-half; distal portion red; outer margin white; membranes greenish white at their bases, centrally red, changing to translucent white near margins. Pelvic-fin rays white with black streaks, and membranes translucent white. Pectoral-fin rays red; membranes transparent. The red fin pigmentation is not attributed to sexual dimorphism or spawning, as it was observed on both males and females throughout the entire year.

Distribution. Micropterus coosae , redefined herein, is endemic to the Coosa River System in the Piedmont region of east Alabama and west Georgia ( Fig. 5 ).

Etymology. This species was named by Hubbs and Bailey (1940) for the locality of the holotype.

Figures

FIGURE 1. Typical pigmentation and pattern of members of the M. coosae species group: M. coosae (Coosa River), 198 mm SL, Cheaha Creek, Hwy 93, 9.6 km N Talladega, Talladega Co., AL; Micropterus cahabae (Cahaba River), 195 mm SL, Shoal Creek, Hwy 119, Shelby Co., AL; M. chattahoochae (Chattahoochee River), 158 mm SL, Centralhatchee Creek, 1.6 km W Centralhatchee, Heard Co., GA; M. tallapoosae (Tallapoosa River), 155 mm SL, Emuckfaw Creek, 4.8 km N Hwy 22, Tallapoosa Co., AL; M. warriorensis (Black Warrior River), 194 mm SL, Calvert Prong, Black Warrior River, 4.0 km N Oneonta, Blount Co., AL; M. cf. coosae (Savannah River), 164 mm SL, Hudson River, jct. Hwy 29 and Hwy 8, Madison Co., GA, 24 May 2009.

FIGURE 2. Pigmentation and pattern of M. coosae (A–C) and M. cahabae (D–F). Micropterus coosae: (A) male (185 mm SL), 7 April 2010; (B) female, (235 mm SL), 16 June 2010; (C) female (76 mm SL), 22 June 2010. Micropterus cahabae: (D) male (195 mm SL), 7 April 2010; (E), female, (142 mm SL), 16 June 2010; (F) male (134 mm SL), 22 June 2010.

FIGURE 5. Distribution of the M. coosae species group in the Mobile Bay and adjacent drainages based on specimens examined. Stars, M. warriorensis; triangles, M. cahabae; circles, M. coosae; squares, M. tallapoosae; plus symbols, M. chattahoochae. Symbols correspond to those in Figure 6.