Cambarus ectopistes Loughman & Williams, 2021

Loughman, Zachary J. & Williams, Bronwyn W., 2021, Cambarus ectopistes sp. nov., a new stream-dwelling crayfish (Decapoda: Cambaridae) from the French Broad, Pigeon, and Nolichucky River watersheds in the Appalachian Mountain region of North Carolina and Tennessee, USA, Zootaxa 5082 (4), pp. 322-340 : 328-337

Cambarus ectopistes Loughman & Williams , sp. nov.

Figures 4A–J , 5 , 8 .

Cambarus (Puncticambarus) robustus . —Cooper 2010: 72, 74, 75 [all in part].—Fullerton, 2002: 13, 16, 21, 27, 31, 40 [all in part].— Simmons & Fraley 2010: 83, 111, 112 [all in part].

Cambarus robustus . —Cooper & Braswell 1995: 116, 126 [all in part].

Cambarus sp. nov. —Dunn 2010: 9, 27, 33, 53, 60, 61, 64-66.

Cambarus (Puncticambarus) sp. nov.— Simmons & Fraley 2010: 110, 114-115.

Diagnosis. Body and eyes pigmented. Base of rostrum broad; anterior portion broad and sub-parallel, moderately excavated, and deflected ventrally, margins thickened to acumen; acumen margins not thickened and strongly converging. Floor of rostrum punctate. Acumen distinctly triangular with prominent dorsally deflected spiniform tubercle at terminus. Areola 2.5–4.9 (x = 3.3, n = 86, s = 0.5) times as long as wide with 7–11 (usually 9) punctations across narrowest point. Juveniles with weak cervical spine; adults with spiniform tubercle along cervical groove. Mandibular, branchiostegal, and orbital regions of carapace with well-developed tubercles. Postorbital ridge not terminating in spine; occasionally terminating in tubercle. Suborbital angle acute, terminating in small tubercle. Total carapace length (TCL) 1.7 – 2.1 (x = 1.9, n = 86, s = 0.1) times longer than width. Form I and II males with hook on ischium of third pereopods only; hook gently curved at apex, overarching basioischial joint in form I males, not reaching basioischial joint in form II males; hooks not opposed by tubercle on basis. Mesial surface of chela possessing two rows of tubercles; mesial most row with 5–9 (x = 7.4, n = 86, s = 0.1) tubercles, second (dorsal) row with 4–8 (= 7.4, n = 86, s = 0.9) tubercles. Chela normally lacking sub-palmar tubercles, rarely with one. Dorsomedian ridge of fixed finger of propodus pronounced. Lateral impression at base of fixed finger present. Mesial margin of palm punctate. Dactyl dorsal margin with well-developed tubercles, especially near junction with propodus. Dactyl and fixed finger each with sharp corneous tip. Form I male palm length 82.5–114.5% (x = 95.9, n = 16, s = 9.3) of palm width, form I male palm length 26.1–30.8% (x = 28.6, n = 16, s = 3.7) of total propodus length; female dactyl length 56.8–66.5% (x = 61.0, n = 37, s = 2.5) of total propodus length. Ventral margin of merus with 7–10 (x = 8.4, n = 86, s = 2.1) spines. First pleopod of form I male with long terminal elements. Central projection not tapering distally; recurved>90º to main shaft of gonopod, possessing well developed subapical notch. Caudal knob absent at lateral base of central projection. Mesial process directed 90° to shaft; nondescript and typical for the genus. Annulus ventralis immovable; distinctly asymmetrical caudally; cephalic portion with median trough leading to strongly sculptured central fossa; exaggerated “S” bend in sinus terminating at caudal edge.

Holotypic male, form I ( Figs. 4A–C, G–J , Table 1 ). Body compressed dorsoventrally ( Fig. 4A ); thoracic section of carapace slightly wider than abdomen. Carapace depth less than carapace width at caudodorsal margin of cervical groove. Total carapace length 50.1 mm; postorbital carapace length (PCL) 42.4 mm. Areola 4.1 times longer than wide, with 10 punctations across narrowest part ( Fig. 4B ); length of areola 35.7% of TCL (42.2% of PCL). Rostrum broad and excavated equally along length; margins thickened and subparallel to acumen; floor of rostrum punctate. Rostrum 1.5 times longer than wide. Acumen distinctly triangular, ending in dorsally deflected corneous tip ( Fig. 4A, B ). Postorbital ridges long, terminating in small tubercle. Suborbital angle acute, lacking pronounced spine or tubercle ( Fig. 4A ). Cervical spine absent; small spiniform tubercle present. Mandibular, branchiostegal, and orbital regions of carapace with several well-developed tubercles; greatest tubercle density in hepatic region. Abdomen slightly longer than carapace, pleura rounded both cephaloventrally and caudoventrally. Cephalic section of telson with 1 large spine in each caudolateral corner. Proximal podomere of uropod with 8 laterodistal spines on mesial lobe; median spine, originating from ventral surface; mesial ramus of uropod with median ridge ending distally in distomedian spine not overreaching margin of ramus. Distal margin of proximal segment of lateral ramus of right uropod having 10 immovable, small spines. Cephalomedian lobe of epistome subtriangular, forming weak angle at junction with endostyle; cephalolateral margins not thickened; zygoma moderately arched ( Fig. 4C ); main body lacking prominent cephalomedian fovea. Antennal scale broadest anteriorly; lateral margin thickened, terminating in large corneous spine; mesial margin setiferous ( Fig. 4D ). Right antennal scale 7.9 mm long, 4.1 mm wide. Tip of right antenna reaching first abdominal terga when adpressed. Mesial surface of palm of chela with two well defined tubercle rows; mesial most row possessing 7 tubercles and second row with 5 ( Fig. 4E ). Palm length 69.9% of palm width; depth of palm 12.3 mm. Ventral surface of palm lacking tubercles. Dorsal longitudinal ridge of dactyl moderately developed, punctate, possessing well defined tubercles ( Fig. 4E - punctations difficult to see in figure). Dorsomedian ridge of fixed finger of propodus well-developed. Possessing a lateral impression at the junction of fixed finger and palm. Dactyl and fixed finger of propodus both with sharp, corneous tips. All measurements and counts from right chela. Carpus with prominent dorsal furrow ( Fig. 4E ), surface lacking extensive punctations; mesial margin with large, procurved spine at about midlength. Distodorsal surface of merus without spines or tubercles. Hook on ischium of third pereopods only; hook gently curved at apex, overarching basioischial joint, not opposed by tubercle on basis. Form I gonopod as described in diagnosis ( Fig. 4F–G ); tip reaching anterior margin of fourth caudomesial boss when abdomen flexed.

Allotypic female ( Fig. 4H , Table 1 ). Differing from holotype in following respects: TCL 43.7 mm; PCL 36.3 mm; areola length 34.6% of TCL (41.6% of PCL); 3.2 times as long as wide; rostrum 1.8 times longer than wide; abdomen length 49.1 mm; antennal scale 5.4 mm long, 3.6mm wide. Mesial surface of palm of chela with two rows of 7 tubercles each; palm length (10.6mm) 68.8% of palm width (15.4 mm); depth of palm 9.1 mm; all measurements and counts from right chela. Annulus ventralis as described in diagnosis ( Fig. 4H ); width of postannular sclerite half total width of annulus ventralis; first pleopods uniramous, reaching central region of annulus ventralis when abdomen flexed.

Morphotypic male, form II ( Fig. 4I–J , Table 1 ). Differing from holotype in the following respects: TCL 40.6 mm and PCL 34.2 mm; areola length 35.2% of TCL (41.8% of PCL), 3.4 times longer than wide; rostrum margins subparallel and thickened; ventrally deflected and moderately excavated, 1.6 times as long as wide; abdomen 41.6 mm long; antennal scale 6.5mm long, 3.6 mm wide. Mesial-most row of palm with 7 tubercles; second row with 5 tubercles; palm length (10.8 mm) 74.4% of width (14.5 mm); all measurements and counts from right chela. Central projection curved 90° to shaft, with complete apex, rounded ( Fig. 4I–J ); hook on ischium of third pereopod small, not reaching basioischial joint.

Size Form I male (n = 15) TCL ranges from 38.3 to 51.8 mm (PCL 23.2–42.2 mm) with a mean TCL of 44.6 mm. Mean TCL of form II male (n = 26) is 38.4 mm, ranging in size from 30.7 to 49.3 mm (PCL 24.4–39.9 mm). Female (n = 78) mean TCL is 43.3 mm and ranges from 29.0 to 53.6 mm (PCL 23.8–45.8mm). The largest specimen examined was a form I female with a TCL of 53.6 mm (PCL 45.8 mm).

Color. Carapace ground color of C. ectopistes sp. nov. ( Fig. 5 ) olivaceous brown to brown; posterior margin of carapace same as ground color, with weak saddle. Hepatic and antennal region of carapace with beige punctations. Postorbital ridge maroon or red-brown. Rostrum margins maroon, red-brown, or brown; acumen olivaceous brown. Cephalic section of carapace immediately anterior to and including cervical groove light olive-brown, brown, rarely green; mandibular abductor scars mottled, ranging from light-brown, brown, to dark brown. Lateral margin of antennal scale olive to light brown; body of antennal scale brown to cream. Antennal flagellum and antennules olivaceous, brown, with bluish hue; dorsal surface of lamella tan to brown; ventral surface light green to olivaceous. Dorsal surface of chela generally olivaceous or light brown, with beige punctations. Denticles on opposable surfaces of fingers yellow, white, or tan. Ventral surface of chela cream or tan. Tubercles on mesial margin of palm rust, redbrown, or maroon. Dorsal surface of carpus orange-brown or olivaceous; region adjacent to and including furrow light brown to olive; large mesial spine cream. Merus olive-brown or olive. Podomeres of pereopods olivaceous, blue-brown, or green-brown; joints of pereopod podomeres orange. Dorsal and dorsolateral surface of abdomen heavily mottled and same colors as carapace; tergal margins cream; abdomen lacking dorsal stripe. Uropod same colors as abdomen. Ventral surface of abdomen and carapace cream. Dorsal ridge of form I gonopod central projection amber; body of central projection, gonopod, and mesial process tan. Form II gonopod and all associated processes cream. Cephalic portion of annulus ventralis pink to pink-cream; ridge of fossa pink; caudal region of annulus ventralis ranges from pink to cream colored.

Type series localities The holotype and allotype were collected from Hurricane Creek at I-40 west crossing, Haywood County, North Carolina. Both specimens were selected from a collection made by C. Dunn on 23 Oct 2009 using minnow traps. The morphotype was collected from Tobes Creek at the confluence with Pigeon River , below Waterville Road , Unicoi County by B.W. Williams, Z.J. Loughman, and E.M. Delekta on 9 Jun 2017 .

Disposition of types The holotype, allotype, morphotype, and 2 paratypes are deposited in the North Carolina Museum of Natural Sciences Non-Molluscan Invertebrate Collection (catalog numbers NCSM 90193 , 90194 , 90195 , and 90196; respectively). Two additional paratypes, 1 MI and 1 F, are deposited in the Smithsonian National Museum of Natural History Invertebrate Zoology Collection ( USNM 1661660 , and 1661661, respectively) .

Range and specimens measured. Cambarus ectopistes sp. nov. occupies a narrow and noncontiguous distribution extending across three major tributaries in the Upper Tennessee River basin, namely the Pigeon River, French Broad River, and Nolichucky River ( Fig. 6A ). The western, or downstream, limit to the current range of the species approximates the transition between the Blue Ridge Mountain and Ridge and Valley ecoregions. The eastern—upstream—limit is less clearly delimited by ecological or geomorphic boundaries but is tightly constrained by 10-digit Hydrologic Unit Boundaries (Hydrologic Unit Code [HUC] 10 = watersheds) ( Fig. 6B ). This distribution is characterized via extensive sampling in and adjacent to the Pigeon, French Broad, and Nolichucky River watersheds, and examination of historic specimen lots housed in the NCSM Non-molluscan Invertebrate Collection ( Fig. 1 ).

We measured 81 specimens from 33 specimen lots, including the type series and additional material housed in the North Carolina Museum of Natural Sciences Non-Molluscan Invertebrate Collection, West Liberty University Crayfish Conservation Lab. Only adult specimens are reported below. This material is from the following locations: NORTH CAROLINA, Haywood County: (1) NCSM 90197 Cold Springs Creek along Cold Springs Creek Road, NW of Fines Creek, 1 F, 1 MII, C. Dunn, 22 Jun 2009; (2) NCSM 5895 , Cold Springs Creek along Cold Springs Creek Road, NW of Fines Creek, C. Dunn, 8 Jun 2009 , 1 MI, 1 MII, 1 F; (3) NCSM 90198 , Hurricane Creek off I-40, NW of Fines Creek, 3 MI, 1 MII, 6 F, C. Dunn, 23 Oct 2009; (4) NCSM 90199 , Big Creek above confluence with Pigeon River , Waterville, C. Dunn, 15 Jan 2009 , 4 MII; (5) NCSM 5884 , Big Creek at Waterville Road, south of Waterville , 1 MII, 1 F, C. Dunn, 18 Jun 2009; (6) NCSM 5882 , Cataloochee Creek at confluence with Walters Lake , NNW of Cove Creek, 2 MII, C. Dunn, 11 Oct 2009; (7) NCSM 4335 , Cataloochee Creek at SR 1395 ( Old Cataloochee Turnpike ), NW of Cove Creek, 2 MII, 2 F, D. Lenat, L. Eaton, B. Tracy, 23 Jul 1997; (8) NCSM 7981 , Cataloochee Creek at Cataloochee Entrance Road , 1 MII, 3 F, A.H. Fullerton, J. Smith, 10 Oct 2001; (9) WLU XXXXX Cataloochee Creek across from Jarvis Palmer Barn, Great Smoky Mountains National Park , 2 MI, 2 F, Z.J. Loughman, B.W. Williams et al., 16 Nov 2016; (10) WLU XXXXX Cataloochee Creek across from Jarvis Palmer Barn, Great Smoky Mountains National Park , 2 MI, 1 MII, 2 F, Z.J. Loughman, B.W. Williams et al., 16 Nov 2016; (11) NCSM 90191 , Pigeon River at Forest Service Road 288, NW of Fines Creek, 1 MI, 2 F, B.W. Williams et al., 17 Nov 2016 ; Madison County: (12) NCSM 25667 , Little Creek at SR 1318 ( Big Laurel Road ), 1 F, E. Fleek, W. Crouch, 18 Sep 2006; (13) NCSM 2130 , Spring Creek along NC 209, 0.3 miles south of junction with SR 1166, 1 MII, 1 F, 1 F, A.L. Braswell, J.E. Cooper, 29 Sep 1984; (14) NCSM 2133 , Spring Creek along NC 209, 0.3 miles south of junction with SR 1166, 1 MI, 2 F, A.L. Braswell, J.E. Cooper, 29 Sep 1984; (15) NCSM 2118 , Shut-in Creek along SR 1183, 1.3 road miles south of junction with US 25/70, west of Hot Springs , 1 F, 2 MII, J.E. Cooper, A.L. Braswell, 25 Sep 1984; (16) NCSM 2119 , Shut-in Creek along SR 1183, 1.3 road miles south of junction with US 25/70, west of Hot Springs , 1 MI, J.E. Cooper, A.L. Braswell, 25 Sep 1984; (17) NCSM 2215 , Shut-in Creek along SR 1183, 1.3 road miles south of junction with US 25/70, west of Hot Springs , 1 F ovig., A.L. Braswell, J.E. Cooper, 25 Sep 1984; (18) NCSM 1805 , Shut-in Creek along Lower Shutin Road (SR 1303), WNW of Hot Springs, 2 F, A.L. Braswell, J.E. Cooper, 23 Jul 1984; (19) NCSM 2203 , Shut-in Creek along SR 1183, 1.3 road miles south of junction with US 25/70, west of Hot Springs , 1 MI, J.E. Cooper, A.L. Braswell, 25 Sep 1984; (20) NCSM 24160 Little Laurel Creek at NC 208, south of Allenstand , 1 MI, 1 F, A.H. Fullerton, J. Smith, 7 Sep 2001; (21) NCSM 24165 , Meadow Fork Creek at Mead Fork Road (SR 1175), 1.6 miles NNE of Joe, 1 MI, A.H. Fullerton, J. Smith, 6 Sep 2001; (22) NCSM 25618 , Big Creek at SR 1312, NNW of Carmen, W.B. Crouch, 22 Sep 2006 , 1 MI; Mitchell County: (23) NCSM 5733 , Hollow Poplar Creek at NC 197, 3 MII, B. Tracy, J. DeBerardinis, A. Rominger, M. Simonson, 21 Jun 2007 ; Yancey County: (24) NCSM uncat., Big Creek at Will Higgins Road (SR 1444), Ramseytown, 1 F, 29 Jan 2008; (25) NCSM 23831 , Cane River at US 19E, Riverside , T.W. Savidge , 1 F, 9 Sep 2002; (26) NCSM 24438 , Cane River at Old Ferguson Mill Dam upstream of US 19E crossing, 1 MI, S.J. Fraley, 18 Jun 2003; (27) NCSM 3922 , Cane River at Miller Chapel, 0.3 miles north of Bloody Fork Road (SR 1387), east of Lewisburg , 1 MII, E.F. Menhinick and Limnology class, 7 Sep 1980; (28) NCSM 4474 , Indian Creek at Prices Creek Road (SR 1126), Cane, 2 F, B. Tracy, D . R. Lenat , 23 Feb 1996; (29) NCSM 90187 , Big Creek along US Highway 19W, north of Lewisburg , 2 MII, B.W. Williams, P.G. Weaver, D . R. Jones , 24 Mar 2019; (30) NCSM 90188 , Cattail Creek at Highway 197, United Methodist Church , Pensacola , 2 F, B.W. Williams, P.G. Weaver, D . R. Jones , 25 Mar 2019 ; TENNESSEE, Cocke County: (31) NCSM 90192 , Tobes Creek at confluence with Pigeon River, below Waterville Road , Browns, 1 MII, B.W. Williams et al., 9 Jun 2017 ; Unicoi County: (32) NCSM 90189 , North Indian Creek at Highway 107, ESE of Unicoi, 1 F, B.W. Williams, P.G. Weaver, D . R. Jones , 24 Mar 2019; (33) NCSM 90190 , Spivey Creek, at intersection of Tilson Mountain Road and Spivey Mountain Road ( Route 19W/36), NE of Flag Pond, 1 MII, 1 F, B.W. Williams, P.G. Weaver, D . R. Jones , 24 Mar 2019 .

Habitat and life history notes. Cambarus ectopistes sp. nov. occupies moderate to large perennial streams with substrates composed primarily of large cobbles and boulders ( Figure 7 ). It uses both stream channel and stream edge habitats and is encountered most often in runs and moderate velocity riffles. This species appears to use pool habitats infrequently in larger streams, whereas in smaller, more moderate-sized streams C. ectopistes sp. nov. was encountered primarily in plunge pools associated with waterfalls, and frequently occurred in pool thalwegs amongst leaf packs. Although C. ectopistes sp. nov. was not usually found in steep, fast-flowing streams—where Cambarus cf. bartonii was predominant—we did encounter several individuals of the species while sampling high gradient second ordered streams in tributaries to the Pigeon River, including Cataloochee and Big Creek drainages in Great Smoky Mountains National Park.

Based on specimens examined for this description, both form I and form II males are present during all months of the year. The incidence of form I males increased from September through May , and form II males were most prevalent from May through October. Ovigerous females were encountered in May and June , females bearing stage I juveniles were collected in late June , stage II juveniles were present on females collected in July , and stage IV juveniles were present in August and November. Juveniles collected on females in November likely would have overwintered with their mothers and would have been recruited into the population the following spring. Few full complements of eggs and juveniles were present. Among those examined were a female collected from Gulf Fork Big Creek, TN on 9 June 2017 with a TCL of 34.2 mm and bearing 116 eggs and a female collected on 16 November 2017 from the type locality with a TCL of 45.0 mm harboring 142 stage I juveniles .

Conservation status. We suggest that C. ectopistes sp. nov. be assigned the status of Special Concern (SC) in North Carolina, vulnerable (G3) using the NatureServe criteria, and vulnerable ( V) using the criteria of the International Union for the Conservation of Nature ( IUCN 2001). Although the distribution of the species spans three major tributaries of the French Broad River basin, the area occupied in each is narrow, ranging from two to four HUC 10s. There is no current connectivity among these three populations. If, for example, the population in the French Broad River declines, there will not be recolonization or immigration from either the Pigeon or Nolichucky. Consequently, habitat alteration, habitat degradation, and fluctuations in water quality in any of these tributaries may have drastic and detrimental effects on the species.

Crayfish associates. Cambarus ectopistes sp. nov. co-occurs with Cambarus cf. bartonii , Cambarus longirostris (Faxon, 1885) , and Faxonius forceps (Faxon, 1884) .

Variation. Several characters, including those of the rostrum and chela, and overall appearance, i.e., gestalt, vary geographically within the range of C. ectopistes sp. nov. Individuals from the Pigeon and French Broad River systems are generally similar to each other, but are noticeably different from those in the Nolichucky and Cane River systems. Specimens from the Nolichucky and Cane Rivers possess a narrower rostrum with reduced margins compared to specimens from the Pigeon and French Broad rivers, which possess a broad rostrum with more inflated, subparallel margins that terminate in a wide short acumen ( Fig. 8A, B ). Despite this variation, all C. ectopistes sp. nov. exhibit thickened and pronounced rostral margins, which are absent on the acumen.

The chela of the French Broad and Pigeon River specimens is robust, with a wide palm, and is subrectangular in shape, whereas that of the Nolichucky and Cane River specimens is comparatively more elongate in appearance, with a narrower palm, and is more subtriangular, and therefore less robust in appearance. Taken as a whole, these differences in the rostrum and chela result in the French Broad and Pigeon River animals seeming more burly than the Nolichucky and Cane River animals.

Juvenile and subadult C. ectopistes sp. nov. differ from adults in both spination and coloration. The postorbital and cervical tubercles can appear sharply spiniform in juveniles and subadults, but are more rounded, or dulled, in adults. The coloration of juveniles and subadults is dominated by olive greens, greys, and blues, in contrast to the browns observed in adults.

Relationships and comparisons. Cambarus ectopistes sp. nov. is morphologically similar to undescribed members of the C. robustus species complex that occur in the southern Appalachians, C. cf. bartonii from the southern Appalachians, and Cambarus reburrus Prins, 1968 . Cambarus ectopistes sp. nov. can be differentiated from C. robustus s.s. —which occurs in northwestern Pennsylvania, New York, New England, and Ontario, Canada —by characters associated with the chela, rostrum, and overall adult color pattern. Cambarus robustus s.s. bears 2–4 subpalmar tubercles on the chela, and typically has rostral margins that are entire to the tip of the acumen; the rostral margins are not thickened. In contrast, the chela of C. ectopistes sp. nov. normally lacks subpalmar tubercles and is more streamlined in appearance than C. robustus s.s. The rostral margins of C. ectopistes sp. nov. are thickened, creating a concavity to the rostrum; this thickness terminates prior to the junction with the acumen, and the margins of the acumen are noticeably not inflated. The coloration of adult C. robustus s.s. is monochromatic on the cephalothorax and abdomen, without mottling. In contrast, adult C. ectopistes sp. nov. is mottled on the dorsal surfaces of both the cephalothorax and abdomen.

In both morphology and color pattern C. ectopistes sp. nov. is most similar to undescribed members of the C. robustus complex that occur in the greater Toe (upper Nolichucky) and Watauga (Holston) watersheds in North Carolina, and Tennessee, North Carolina, and Virginia, respectively. This is unsurprising given the close phylogenetic relationships among these taxa and the similar habitats in which each occurs. Whereas the chela of C. ectopistes sp. nov. lacks subpalmar tubercles, and individuals exhibit a wide rostrum, C. cf. robustus from the Toe watershed exhibit subpalmar tubercles on the chela, and have a noticeably more acuminate rostrum. Similarly, C. ectopistes sp. nov. differs from C. cf. robustus from the Watauga watershed in both rostrum and chela morphology, as well as coloration. The rostrum of C. ectopistes sp. nov. is proportionately longer relative to total carapace length than that of the Watauga C. cf. robustus , and the chela of the former is less rotund.

Cambarus reburrus and C. cf. bartonii both occur in the French Broad, and Pigeon, French Broad and Nolichucky River watersheds, respectively. Cambarus reburrus is readily differentiated from C. ectopistes sp. nov. by characters of the rostrum, chela, and carapace. Cambarus reburrus possesses a narrow acuminate rostrum, a prominent cervical spine, and has a narrow chela that typically terminates in red or orange coloration. In contrast, C. ectopistes sp. nov. typically has a broad non-acuminate rostrum, a robust chela that does not terminate in orange or red coloration, and lacks cervical spines.

Cambarus cf. bartonii in western North Carolina and eastern Tennessee has frequently been misidentified as C. cf. robustus due to presence of two rows of tubercles on the mesial margin of the palm in both taxa—a character typically used to identify members of the C. robustus complex—and color pattern, which is often heavily mottled with both species. Cambarus cf. bartonii and C. ectopistes sp. nov. can be differentiated from each other by the overall shape of the chelae, chela morphology, and rostrum morphology. The chela of Cambarus cf. bartonii is truncated and subrectangular whereas those of C. ectopistes sp. nov. is more elongate and range from subrectangular to subtriangular. Tubercles on the mesial margin of the palm in C. cf. bartonii are usually arranged in a manner that gives the appearance of two disorganized rows, whereas in C. ectopistes sp. nov. they consistently form an organized double row. Cambarus cf. bartonii exhibits two pronounced subpalmar tubercles that are directly adjacent to each other; subpalmar tubercles very rarely are found on the chela of C. ectopistes sp. nov. The rostral margins of Cambarus cf. bartonii are thickened, as in C. ectopistes sp. nov., although are continuous in thickness to the distal point of the acumen; in contrast, the rostral margins of Cambarus ectopistes sp. nov. are noticeably thicker than the margins of the acumen. In addition, the rostrum of C. cf. bartonii is shorter and more truncate in comparison to the prominent rostrum exhibited by C. ectopistes sp. nov.

Common name. Cambarus ectopistes sp. nov. was identified as a putative unique taxon nearly 30 years ago by the late Dr. John E. Cooper (former Curator of Crustaceans at the NCSM) and Roger Thoma, both of whom believed it to be narrowly endemic, restricted to Cataloochee Creek and neighboring tributaries of the Pigeon River. The crayfish has since been colloquially referred to as the “Cataloochee morph.” We therefore suggest Cataloochee Crayfish as the common name for this species.

Etymology. The species epithet—as a noun—is derived from the genus name of the extinct passenger pigeon, Ectopistes migratorius (Linnaeus, 1766), for which the Pigeon River is named. The Greek word ectopistes means “a wanderer” ( Choate 1985). We chose this epithet based on the geographic association, in part, of C. ectopistes sp. nov. with the Pigeon River, and also to emphasize the need for broader education about the conservation concerns and needs of crayfishes in general.

Figures

FIGURE 1. Map showing localities of all specimens examined for this study, including newly sampled material and individuals in the North Carolina Museum of Natural Sciences (NCSM) Non-molluscan Invertebrates Collection originally identified as Cambarus robustus, C. cf. robustus, or C. (Puncticambarus) sp.

FIGURE 4. Cambarus ectopistes sp. nov.: (A) lateral cephalothorax; (B) dorsal cephalothorax; (C) epistome; (D) antennal scale; (E) dorsal right chela; (F) mesial form I gonopod; (G) lateral form I gonopod; (H) annulus ventralis; (I) mesial form II gonopod; (J) lateral form II gonopod.A–G from holotype (NCSM 90193); H from allotype (NCSM 90194); and I–J from morphotype (NCSM 90195).

FIGURE 5. Live color of A) adult male and B) adult female C. ectopistes sp. nov. from the Pigeon River, NC. Photos by Michael Perkins and W.T. Russ (North Carolina Wildlife Resources Commission).

FIGURE 6. Maps (A. relief, B. HUC 10 boundaries) showing the distribution of C. ectopistes sp. nov. in the Pigeon River (PR), French Broad River (FB), Nolichucky River (NOL), and Cane River (CANE) systems. * Denotes the sampling locality on Paint Creek, Tennessee.

FIGURE 7. Examples of stream habitat in which C. ectopistes sp. nov. was encountered.

FIGURE 8. Intraspecific variation in C. ectopistes sp. nov. occurs most notably in the shape of the rostrum.A, Nolichucky and Cane Rivers; B, French Broad and Pigeon Rivers.