Cambarus (Puncticambarus) guenteri, Loughman, Zachary J., Henkanaththegedara, Sujan M., Fetzner Jr, James W. & Thoma, Roger F., 2017

Loughman, Zachary J., Henkanaththegedara, Sujan M., Fetzner Jr, James W. & Thoma, Roger F., 2017, A case of Appalachian endemism: Revision of the Cambarus robustus complex (Decapoda: Cambaridae) in the Kentucky and Licking River basins of Kentucky, USA, with the description of three new species, Zootaxa 4269 (4), pp. 460-494 : 468-475

Cambarus (Puncticambarus) guenteri , new species

Figures 3–5 , Table 4

Cambarus robustus Girard, 1852:90 [in part];— Taylor and Schuster, 2004:103, Figs. 74A,B, 75. Cambarus (Puncticambarus) robustus .—Hobbs, 1969:101, Figs. 1 c, 13a, 17o [in part]; 1974b:21, Fig. 87 [in part]; 1989:27, Fig. 104 [in part].

Diagnosis. Body and eyes pigmented. Rostrum broad, moderately excavated, and deflected anteriorly, margins not thickened, subparallel to slightly converging anteriorly. Acumen distinctly triangular with prominent dorsally directed spiniform tubercle at terminus. Areola 3.9–7.8 (x ‾ = 5.3, n = 23, SE = 0.91) times as long as wide with 4–8 (usually 5) punctations across narrowest point. Cervical spine rarely present (19% of individuals); usually 3–4 (x ‾ = 3.4, SE = 0.7) tubercles present instead of spines (81% of individuals). Mandibular, branchiostegal, and orbital regions of carapace with well-developed tubercles. Postorbital ridges short; spiniform, dorsally directed tubercle present in juveniles and subadults; adult postorbital ridge terminating in rounded tubercle; rarely spiniform tubercles present in adults. Suborbital angle present. Total carapace length (TCL) 1.7–2.0 (x ‾ = 1.9, n = 23, SE = 0.06) times longer than width. Form I and II males possessing 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 chelae with two rows of tubercles; mesial most row with 8–13 (x ‾ = 8.7, n = 23, SE = 1.2) tubercles, second dorsal row with 6–12 (x ‾ = 6.1, n = 23, SE = 1.1) tubercles. Tubercles rarely extend from mesial surface to body of palm forming two additional disorganized rows of tubercles. Ventral surface of chelae with 1–2 (x ‾ = 1.4, n = 23, SE = 0.89) subpalmar tubercles near the dactyl/ propodus junction; when more than one subpalmar tubercle present, tubercles oriented tightly together. Dorsal longitudinal ridge of dactyl consisting of several well developed pronounced scattered tubercles. Dorsomedian ridge of fixed finger of propodus pronounced. Well defined lateral impression at the junction of the fixed finger with the propodus. Dactyl and fixed finger with sharp corneous subterminal tip. Form I male palm length 62.6– 66.8% (x ‾ = 64.3%, n = 5, SE = 1.7%) of palm width, Form I male palm length 27.2–29.7% (x ‾ = 27.9%, n = 5, SE = 1.0%) of total propodus length; female dactyl length 62.3–64.2% (x ‾ = 63.2%, n = 5, SE = 0.75%) of total propodus length. First pleopod of Form I male with short terminal elements. Central projection not tapering distally; recurved> 90° to main shaft of gonopod, with distinct subapical notch. Mesial process directed 90° to shaft, bent cephalolaterally; inflated cephalically, tapering to distinct caudal point at or slightly beyond terminance of central projection. Annulus ventralis immovable; distinctly asymmetrical posteriorly; cephalic portion with median trough leading to strongly sculptured central fossa; exaggerated “S” bend in sinus terminating at caudal edge.

Description of Holotypic Male, Form I. ( Fig. 3 A–D, H, G, J, K; Table 4). Body somewhat compressed dorsoventrally ( Fig. 3 A); carapace posterior to cervical groove slightly wider than abdomen. Carapace depth less than carapace width at caudodorsal margin of cervical groove. Total carapace length 43.6 mm; PCL 35.2 mm. Areola 5.8 times longer than wide, with 6 punctations across narrowest part ( Fig. 3 H); length of areola 38.3% of TCL (47.4% of PCL). Rostrum excavated, more so anteriorly than posteriorly; margins not thickened, subparallel and continuous to base of acumen; floor of rostrum with numerous punctations. Rostrum 1.8 times longer than wide. Acumen distinctly triangular, ending in dorsally directed corneous tip ( Fig. 3 H). Postorbital ridges well developed, terminating in spiniform tubercles. Suborbital angle distinct, with tubercle ( Fig. 3 A). Cervical spine absent, but a well developed tubercle present. Mandibular, branchiostegal, and orbital regions of carapace ornamented with well-developed tubercles; greatest tubercle density in hepatic region. Abdomen supraequal in length to carapace, pleura rounded cephaloventrally, angled caudoventrally. Lateral margins of terga angulate; lateral margin of second pleuron deeply furrowed. Cephalic section of telson with 2 large spines in each caudolateral corner. Proximal podomere of uropod with distal spine on mesial lobe; mesial ramus of uropod with median ridge ending distally in distomedian spine not overreaching margin of ramus; laterodistal spine pronounced. Distal margin of proximal segment of lateral ramus of right uropod having 14 immovable, small spines and 1 lateral, large movable spine. Cephalomedian lobe of epistome subtriangular, zygoma moderately arched ( Fig. 3 G); cephalolateral margins thickened, forming sharp angle at junction with endostyle ( Fig. 3 G). Body of epistome possessing prominent cephalomedian fovea. Antennal scale broadest proximally; lateral margin thickened, terminating in large corneous spine; setiferous on mesial margin. Right antennal scale 7.4 mm long, 2.8 mm wide ( Fig. 3 D). Tip of right antenna reaching middle of telson when adpressed. Mesial surface of right chela with 2 well-formed rows of tubercles; mesial most row with 9 tubercles, second dorsal row with 7 tubercles ( Fig. 3 K). Several disorganized tubercles present on upper mesial surface of palm. Palm length 65.6% of palm width; depth of palm 9.9 mm. Ventral surface of palm containing 3 subpalmar tubercles forming a triangle. Dorsal longitudinal ridge of dactyl developed and possessing moderate sized tubercles ( Fig. 3 K); dactyl terminating in large corneous spine. Dorsomedian ridge of fixed finger of propodus pronounced. Fixed finger junction with well defined lateral impression; numerous setiferous punctations present with sharp, corneous tip. All measurements and counts from right chela. Carpus with prominent dorsal furrow ( Fig. 3 K) and 4 weak dorsomesial tubercles; remainder of surface with scattered setiferous punctations; mesial margin with large, procurved spine near midlength, and reduced proximal spine. Distodorsal surface of merus with 9 spiniform tubercles; ventrolateral ridge with 2 small spines and one large, corneous distal spine; ventromesial ridge with 3 well-developed spines. Carapace depth less than width. Hook on ischium of third pereopods as described in diagnosis. Form I gonopod as described in diagnosis ( Fig. 3 B–D); tip reaching anterior margin of fourth caudomesial boss.

Description of Allotypic Female. ( Fig. 3 I, Table 4).––Differing from holotype in following respects; carapace height less than carapace width (17.0 and 21.8 mm, respectively); TCL 42.2 mm, PCL 34.3 mm. Areola length 33.8% of TCL (41.7% of PCL), 5.3 times as long as wide. Posterior portion of rostrum more excavated than anterior portion; rostrum 1.9 times longer than wide. Abdomen length 43.9 mm. Mesial surface of chelae with 2 rows of tubercles; mesial most row with 6 tubercles, second dorsal row with 6. Palm length (9.6 mm) 67.1% of palm width (14.3 mm); depth of palm 6.9 mm. All measurements and counts from right chela. Antennal scale 6.8 mm long, 3.1 mm wide. Annulus ventralis as described in diagnosis ( Fig. 3 I); width of postannular sclerite half total width of annulus ventralis; first pleopods uniramous, reaching central region of annulus ventralis when abdomen flexed. Lacking all male secondary sexual traits.

Description of Morphotypic Male, Form II. ( Fig. 3 E–F, Table 4).––Differing from holotype in the following respects: carapace height less than carapace width (18.1 and 23.7 mm respectively); TCL 44.1 mm and PCL 37.0 mm. Areola length 29.0% of TCL (34.6% of PCL), 3.9 times longer than wide. Rostrum margins subparallel to base of acumen; rostrum ventrally deflected and excavated; rostrum 2.2 times as long as wide. Abdomen 43.9 mm long. Mesial row of tubercles on palm of chela with 8 tubercles; second dorsal row with 8 tubercles. Palm length (14.3 mm) 65.0% of palm width (22.0 mm). All measurements and counts from right chela. Antennal scale 7.9 mm long, 3.2 mm wide. Gonopods reaching anterior margin of 4th pereopod caudomesial boss. Central projection curved 90° to shaft, with complete apex; rounded ( Fig. 3 E–F). Mesial process tapered, bulbous, directed caudolaterally. Hook on ischium of third pereopod small, not reaching basioischial joint.

Size. Form I male (n = 5) TCL ranges in size from 39.0– 49.3 mm (PCL 32.2–40.8 mm) with a mean TCL of 44.3 mm. Form II male (n = 11) mean TCL is 44.8 mm and ranges in size from 36.6–53.7 mm (PCL 30.1–44.8 mm). Female (n = 7) TCL mean is 43.3 mm and ranges from 32.4–55.5 mm (PCL 23.0– 45.5 mm). The largest specimen examined was a female with TCL of 55.5 mm (PCL 45.5 mm).

Color in life. Cambarus guenteri ( Fig. 4 ) cephalic section ground color light to chestnut brown; posterior margin of carapace light blue to green. Hepatic and antennal region of carapace punctuated with cream, olive, or tan tubercles. Postorbital ridge color same as carapace to orange-brown. Rostrum margins and acumen cream to red-brown or tan, rarely red. Branchiostegal region olivaceous brown to tan; occasional black saddle present in and around cervical groove; mandibular abductor scars ranging from cream to light-brown. Lateral margin of antennal scale cream to light brown; body of antennal scale olivaceous-brown to cream. Antennal flagellum and antennules green-brown, with olivaceous hue; dorsal surface of lamellae tan to brown; ventral surface light-green to olivaceous. Dorsal surface of chelae olivaceous brown, red-brown, brown to tan with red-brown highlights, no mottling; mesial, second dorsal row, and dorsal surface of dactyl tubercles cream, tan or red-brown. Distal end of dactyl and propodus terminating in orange; South Fork Kentucky River population with distal margin of dactyl and propodus terminating in crimson red. Denticles on opposable surfaces of fingers yellow, white, or tan. Ventral surface of chelae cream or tan. Dorsal surface of carpus cream, light brown or red-brown; occasionally olivaceous brown; region adjacent to and including furrow red-brown to brown; carpus spine cream. Merus orange-brown, cream, or olivaceous brown. Podomeres of pereopods light cream, tan, bluish, or olivaceous-brown; joints of pereopod podomeres pink. Dorsal and dorsolateral surface of abdomen same color as carapace; anterior region of abdomen with slight olivaceous tint; tergal margins brown to reddish brown. Majority of South Fork Kentucky River animals have reticulated cephalothoraxes with dark brown mottling and two distinct dark-brown dorsal stripes present from junction with cephalothorax to junction with uropods and telson. Uropods brown, red, redbrown to pink-brown, with olivaceous tint; margins gray to brown. 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 associated processes cream. Cephalic portion of annulus ventralis pink to pinkcream; ridge of fossa pink; caudal region of annulus ventralis ranges from pink to cream.

Type locality. Silver Creek at Hagan Mill Road Crossing, 5.5 km (3.4 mi) southwest of Richmond, Madison County, KY, 37.69196/-84.36081 ( Fig. 5 , star). At this site, Silver Creek is 15–20 m wide, and consists of a long 50m + run. Directly under the Hagan Mill Road bridge, abundant large slab boulders and boulders are present along the right descending bank. Water depth ranged from 0.2–1.5 m deep. Here the type series was collected along with several additional specimens on 27 October 2014 by ZJL and C. G. Vopal. Orconectes juvenilis ( Hagen, 1870) is also abundant at this location.

Disposition of types. The holotype, allotype, and morphotype are deposited in the North Carolina Museum of Science ( NCSM), Raleigh, N.C. (catalogue numbers NCSM 27206, 27207 and 27208, respectively) . Paratypes are deposited in the USNM, Washington D.C. ( USNM 1422179 ) .

Range and specimens examined. Cambarus guenteri is endemic to the Cumberland Plateau and the junction of the Cumberland Plateau and the Inner Bluegrass physiographic provinces of Kentucky. Within these provinces, C. guenteri appears to be limited to the Middle Kentucky River and South Fork Kentucky River basins of Kentucky in Clay, Estill, Madison, and Owsley counties ( Fig. 5 ).

All of the following collections, with the exception of the previously discussed type series, are either housed in the Branley A. Branson Museum at Eastern Kentucky University (denoted with EKU), the United States National Museum (denoted with USNM), or the West Liberty University Astacology Collection (denoted with the prefix WLU). The following abbreviations occur in the text: Cr. = Creek; R. = River; Frk. = Fork ; UNT = Un-named tributary; ZJL14—Collectors included ZJL 2014 field crew which consisted of S. S. Bell, Z. W. Dillard, N. M. Sadecky, L. K. Sadecky, E. Tidmore and E. M. Tennant.

KENTUCKY: Clay Co. (1.) WLU 2096 , Red Bird Cr., 36.9488/-83.5323 , 8 June 2014, 1 Jv. ZJL14. (2.) WLU 2101, Collin’s Cr., 37.04255/-83.8102, 14 June 2014, 1 IM, ZJL14. (3.) WLU 2103, Thomas Cr., 37.0387/- 83.6631, 8 June 2014, 2F, ZJL14. (4.) WLU 2115, Grays Frk., 37.2001/-83.6631, 8 June 2014, 12 F, 11 IIM, ZJL14. (5.) USNM 147031, Collin’s Frk., 37.2599/-83.6685, 19 October 1974, 1 IIM, R. Bouchard. Jackson Co. (6.) EKU 323 , Cavanaugh Cr., 37.3871/-84.0306, 1 IIM. (7.) EKU 2484 , Rocklick Cr., 37.5178/-84.0740, 29 October 1988, 2 IIM, P. Ceas, J. Roy and M. Thomas . Leslie Co. (8.) WLU 2097 , Chandler Br., 37.1647/-83.5169 , 10 June 2014, 1F, ZJL14. Madison Co. (9.) NCSM 27206, 27207 , 27208 ; USNM 1422179, Silver Cr. TYPE LOCALITY, 37.6919/-83.3608, 26 October 2016, 4 IM, 3 IIM, 5 F, 1 Jv. Owsley Co. (10.) WLU 2093 , Cow Cr., 37.4341/-83.5640, 7 June 2014, 4 F, 1 IM, 2 IIM, 1 Jv. ; WLU 2300, 25 October 2014, 1 F, ZJL14. (11.) WLU 2098, Paw Paw Cr., 37.5278/-83.6831, 7 June 2014, 2 F, 1 IIM, ZJL14. (12.) WLU 2102, Meadow Cr., 37.4828/-83.6453, 7 June 2014, 2 IIM, 2 Jv, ZJL14. (13.) WLU 2104, Rt. Frk. Buffalo Cr., 37.3537/-83.6348, 7 June 2014, 2F, 4 IIM, ZJL14. (14.) WLU 2105 , S Frk. Kentucky R., 37.5237/-83.6665 , 11 June 2014, 2 F, 2 IIM, ZJL14. (15.) WLU 2116, White Oak Cr., 37.4955/-83.7065, 7 June 2014, 1 F, 1 IIM, 1 Jv, ZJL14. Wolfe Co. (16.) WLU 2288 , UNT, 37.7399/-83.5069, 28 April 2012, 1 F, D. Foltz, C. Z. Loughman, Z. J. Loughman and K. T. Skalican. (17.) WLU 2290 , Eighth Br., 37.7557/-83.3460 , 28 April 2012, 1 IIM, D. Foltz, C. Z. Loughman, Z. J. Loughman and K. T. Skalican. (18.) WLU 2294, Holly Cr., 37.6508/-83.4757, 28 April 2012, 1 F, D. Foltz, C. Z.Loughman & Z. J. Loughman, K. T. Skalican.

Habitat and life history notes. Cambarus guenteri occurs in small to large wadeable streams with cobble/ boulder substrates. In higher ordered streams, C. guenteri is frequently encountered under large slab boulders, boulders, and other substrate debris in both runs and riffles. Pools are rarely utilized by C. guenteri in the absence of large substrate items. In lower order streams, C. guenteri utilizes mainly large boulders and slabs in riffles and runs. Juveniles in both lower and higher order streams frequent leaf packs, root wads, and course woody debris snags. Cambarus guenteri does not normally occur in ephemeral headwater situations, but will utilize these habitats near headwater confluences with more permanent waterways. Higher gradient streams in the South Fork Kentucky River harbor the largest populations (ZJL, personal observation).

Future research is needed to elucidate the life history of this species. Both Form I and Form II males have been collected in all months of the year, except November, December and February ( Taylor & Schuster 2004). Ovigerous females have not been collected. Females collected in June 2012 displayed active glair glands. Juveniles were collected en-masse from leaf packs in October, 2012 indicating egg extrusion likely occurs over the summer months (ZJL personal observations).

Conservation status. Cambarus guenteri should be listed as currently stable (CS) using American Fisheries Society criteria ( Taylor et al. 2007), and assigned a G4 (Apparently Stable) ranking using Master (1991) global conservation criteria for conservation listing. Cambarus guenteri should be listed as data deficient (DD) using the International Union for the Conservation of Nature (IUCN 2001) criteria due to the limited information available on its biology.

Crayfish associates. Cambarus guenteri has been collected along with Cambarus (Cambarus) bartonii cavatus Hay, 1902 ; Cambarus (Depressicambarus) cf. sphenoides Hobbs, 1968 ; Cambarus (Jugicambarus) aff. dubius Faxon, 1884 ; Cambarus (Jugicambarus) cf. jezerinaci Thoma, 2000 ; Orconectes (Procericambarus) cristavarius Taylor, 2000 and Orconectes (Procericambarus) juvenilis ( Hagen, 1870) .

Variation. Chelae morphology differs slightly between Upper and Middle Kentucky River mainstem populations and animals from the South Fork Kentucky River. Chelae of South Fork Kentucky River populations are more robust when compared to Middle Fork and Upper Kentucky River populations, which have more subtriangular chelae. In addition to chelae morphology, considerable variation is observed in C. guenteri color pattern. Cambarus guenteri in the South Fork Kentucky River display mottling and abdominal striping, along with a deep crimson red coloration on the distal end of the dactyl and propodus. Upper Kentucky River populations, including the type population, lack mottling, abdominal striping and are somewhat drab (“typical” coloration). Animals collected from the confluence of the South Fork and North Fork at the origin of the Kentucky River mainstem are intergrades of the “typical” and “striped color” pattern, displaying orange chelae tips and barely discernable abdominal stripes.

Relationships and comparisons. Cambarus guenteri is placed in the subgenus Puncticambarus based on its elongate chelae, its broad, densely punctate areola that is 2.1 to 6.2 times as long as broad, and the presence of a subapical notch on the Form I male gonopod (Hobbs 1969; Cooper 2001). Among described members of the subgenus, C. guenteri is most similar to C. hazardi and C. taylori . Cambarus guenteri differs from C. hazardi in rostral anatomy, chelae ornamentation, and overall spination. The rostrum of C. guenteri is not as excavated and the overall rostral shape is also somewhat acuminate when compared to the spatulate, broad, and moderately to deeply excavated rostrum of C. hazardi .

The chelae of C. guenteri lack a deeply excavated lateral impression, maintain well organized rows of tubercles on the mesial margin of the palm, and usually possess 2–3 subpalmar tubercles. In C. hazardi , the lateral impression is deep and exaggerated, the mesial margin tubercles consist of up to three rows of tubercles with several tubercles extending onto the chelae palm, and have 2–5 scattered subpalmar tubercles. The presence or absence of both cervical spines and tubercles is an important character that can be used to differentiate C. guenteri from C. hazardi . Normally C. guenteri has either a grouping of well-defined cervical tubercles or occasionally small cervical spines; C. hazardi lacks cervical spines and if present, has a series of small undefined cervical tubercles. South Fork of the Kentucky River populations of C. guenteri chelae are marked in crimson red while Cambarus hazardi chelae are concolorous.

Cambarus guenteri can be differentiated from C. taylori by rostrum and chelae anatomy, spination on the cephalothorax, gonopod shape, annulus ventralis anatomy, and coloration. The rostrum of Cambarus guenteri is broader, more angled at the acumen junction, and moderately excavated compared to the rostrum of C. taylori , which is more lanceolate and shallow. Cambarus guenteri from the South Fork of the Kentucky River have more subrectangular chelae which are easily differentiated from C. taylori , which possess elongate, subtriangular chelae. Cambarus guenteri subpalmar tubercles are arranged in a triangular shape; C. taylori subpalmar tubercles normally are arranged in a line or an “L” shape. Finally, palm length/palm width ratios are significantly smaller in C. guenteri (x ‾ = 65.8%, SE = 0.53%) compared to C. taylori (x ‾ = 74.4, SE = 2.1%).

Reproductive structures in both males and females can also be used to discern these species. On the gonopod of C. guenteri the mesial process extends laterally parallel to the central projection at a 90° angle to the gonopod shaft ( Fig. 3 B–C). In C. taylori , the Form I male mesial process is oriented at an angle of 65–75° to the gonopod shaft, and terminates in a notch ( Fig. 6 B–C). Though not entirely consistent, the anatomy of the annulus ventralis can also be used to differentiate between both species. In C. guenteri , the annulus sinus is oriented to the left in greater than 98% of individuals whereas in C. taylori , the annulus sinus is oriented to the right in>95% of individuals.

Four other members of the subgenus Puncticambarus occur in Kentucky and are easily separated from C. guenteri using morphology. Cambarus callainus Thoma et al., 2014 differs from C. guenteri by possessing a single row of tubercles on the mesial margin of the palm, compared to the double row of tubercles found in C. guenteri . Additionally, C. callainus has an elongate, narrow lanceolate rostrum compared to the broad rostrum in C. guenteri . Cambarus theepiensis Loughman et al., 2013 differs morphologically from C. guenteri in rostral anatomy. In C. guenteri the rostral margins are not as thickened and are subparallel while in C. theepiensis the rostral margins are noticeably thickened. Both C. callainus and C. theepiensis occur outside the Kentucky River basin in Kentucky, and are allied with the Big Sandy watershed of eastern Kentucky ( Thoma et al. 2014).

Both C. buntingi Bouchard, 1973 and C. cumberlandensis Hobbs and Bouchard, 1973 can be differentiated from C. guenteri by rostral anatomy as well. Cambarus guenteri lacks rostral spines. Cambarus cumberlandensis possess pronounced rostral spines as well as linear rostral margins compared to the more sinuous rostral margin shape found in C. guenteri . Cambarus buntingi also possess rostral tubercles that are much more reduced in size and shape compared to C. cumberlandensis . Finally, both species differ markedly in coloration compared to C. guenteri . Neither C. cumberlandensis nor C. buntingi occur in the Kentucky River basin, but they do both occur in the Cumberland River catchment in Kentucky. Cambarus guenteri differs from nominate C. robustus by having significantly smaller palm length/palm width (x ‾ C. guenteri = 65.8%, SE = 0.5%; x ‾ C. robustus = 67.2%, SE = 0.6%), carapace length/carapace width (x ‾ C. guenteri = 52.6%, SE = 0.4%; x ‾ C. robustus = 54.3%, SE = 0.3%), and rostrum length/rostrum width (x ‾ C. guenteri = 31.3%, SE = 1.0%; x ‾ C. robustus = 30.5%, SE = 0.9%) ratios.

Etymology. It is with great pleasure that we name this species in honor of Dr. Guenter A. Schuster, Professor Emeritus, Eastern Kentucky University. Dr. Schuster dedicated his professional career to teaching undergraduates, graduate students and professional biologists about the diversity, biology, and conservation of freshwater invertebrates, with a particular influence on biologists from the bluegrass state, and he is a coauthor of the definitive work on the crayfishes of Kentucky. He instilled in those he educated a sense of wonder and appreciation for these organisms, which has undoubtedly led to the conservation of more than one freshwater mussel or crayfish. The common name for C. guenteri is the Redbird Crayfish in reference to the Redbird River drainage where large populations of C. guenteri occur.

Common name. Redbird Crayfish.

Figures

FIGURE 1. Non-metric Multi-Dimensional Scaling (NMDS) ordination plot showing morphometric variation among crayfish specimens (stress = 0.081; Non-metric fit R 2 = 0.993; linear fit R 2 = 0.974). Each number represents an individual specimen and the relative distance between two points represents the similarity (or dissimilarity).

FIGURE 3. Cambarus guenteri, new species; all from holotype male, Form I (NCSM 27206), except E and F from morphotype male, Form II (NCSM 27208), and I from allotype female (NCSM 27207): A. lateral aspect of carapace; B – D. mesial and lateral aspect of Form I male gonopod respectively; E – F. mesial and lateral aspect of Form II gonopod respectively; G. ventral aspect of epistome; H. dorsal aspect of dorsal carapace; I. ventral aspect of the annulus ventralis; J. dorsal aspect of the antennal scale; K. dorsal aspect of the distal podomere of the right cheliped. Plate by Guenter Shuster.

FIGURE 4. Cambarus guenteri, new species. Form I male. Photograph by Guenter Schuster.

FIGURE 5. Map showing the distribution of Cambarus guenteri, new species, in the Kentucky River basin. Red circles indicate sampling localities where the species was detected. Red circle with star indicates the type locality. Gray shaded polygons indicate the different river sub-basins discussed in the text. Colored lines indicate stream order (Strahler 1957). Map inset abbreviations: LKy = Lower Kentucky River, UKy = Upper Kentucky River, SF = South Fork Kentucky River. Map generated using Google MyMaps.

FIGURE 6. Cambarus hazardi, new species; all from holotype male, Form I (NCSM 27212), except E and F from morphotype male, Form II (NCSM 27214), and I from allotype female (NCSM 27213): A. lateral aspect of carapace; B – D. mesial and lateral aspect of Form I male gonopod respectively; E – F. mesial and lateral aspect of Form II gonopod respectively; G. ventral aspect of epistome; H. dorsal aspect of dorsal carapace; I. ventral aspect of the annulus ventralis; J. dorsal aspect of the antennal scale; K. dorsal aspect of the distal podomere of the left cheliped. Plate by Guenter Schuster.