Cambarus franklini Perkins, Williams & Russ, 2019

Perkins, Michael A., Williams, Bronwyn W. & Russ, William T., 2019, Cambarus franklini, a new crayfish (Decapoda: Cambaridae) from the Catawba River Basin in western North Carolina, USA, Zootaxa 4568 (3), pp. 520-532 : 525-531

Cambarus franklini Perkins, Williams & Russ , sp. nov.

Figures 3 A–J, 4, Table 3

Diagnosis. Body and eyes pigmented. Rostrum lanceolate, weakly excavated, ventrally deflected distally, with rostral margins thickened and entire to acumen, subparallel, spines or tubercles absent. Median carina not present. Acumen well-defined, with prominent terminal, dorsally deflected, spiniform tubercle. Areola 1.4 to 4.2 (x̄=2.0, n=64) times as long as wide, with 5–7 punctations through the narrowest point. Carapace somewhat compressed dorsoventrally, subovate in cross-section; lateral portion of branchiostegal region heavily punctate; 1–2 welldefined cervical spines. Prominent branchiostegal spines present. Postorbital ridge developed, terminating in spiniform tubercle. Suborbital angle obtuse with well-defined terminal tubercle. Well-developed hepatic spines present in small number (8%) of individuals examined.

Mesial palm of chelae with one prominent row of tubercles; very weak secondary row present in some individuals, becoming undetectable after preservation (MAP, personal observation). First row with 5–7 welldeveloped cristiform tubercles, second row (if present) with 1–4 weakly-defined tubercles. Inconspicuous tufts of elongate setae at base of opposable propodus in approximately 40% of individuals examined (n=64). Opposable margin of propodus typically with 6–7 tubercles, from base consisting of 1–2 smaller tubercles, an enlarged tubercle, 3–4 smaller tubercles, and a sharply pointed fourth tubercle; denticles extending on average 63.2% of distal length. Opposable margin of dactyl with 6–7 tubercles, from base consisting of 2–3 smaller tubercles, an enlarged tubercle, followed by 3–4 smaller tubercles; denticles extending an average of 54.1% of distal length. Palm length to dactyl length ratio averaging 0.59. Weak dorsomedian longitudinal ridge on propodus, typically with tubercles on dorsal surface of dactyl. Sharp corneous tips present on dactyl and fixed finger of propodus. Carpus with one large spine on mesial margin, slightly ventral of midpoint, with one additional large spine on ventral surface of carpus, anterior of midpoint; one smaller spine towards posterior mesial margin of carpus.

Gonopod of form I male with long terminal elements. Central projection not tapered, curved 90° to shaft, with conspicuous subapical notch, slightly subequal in length to mesial process. Mesial process curved 90° to main shaft, conically shaped at base, tapering to a rounded point projecting just beyond margin of the main shaft. Hooks on ischium of third pereiopods in form I and II males. Female annulus ventralis asymmetrical and appearing sclerotized caudally; distinct “S”-shaped bend, terminating in caudal portion; cephalic portion consists of median trough leading to central fossa, not sclerotized.

Holotypic Male, Form I ( Fig. 3 A–C, G–J; Table 3). Body somewhat compressed dorsoventrally; carapace posterior to cervical groove wider than abdomen. Carapace width greater than carapace depth at caudodorsal margin of cervical groove. Total carapace length 33.8mm, PCL 28.5mm. Areola 2.4 times longer than wide, broad with 7 punctations across the narrowest section; length of areola 36.1% of TCL. Rostrum excavated; margins slightly thickened, subparallel and continuous to acumen; floor of rostrum with numerous punctations. Rostrum 1.7 times longer than wide, lanceolate, acumen well-defined, ending in dorsally deflected corneous tip. Postorbital ridge developed, terminating in spiniform tubercle. Suborbital angle obtuse with well-defined terminal tubercle. Prominent cervical spine present. Orbital, branchiostegal, and mandibular regions of carapace with well-developed tubercles; greatest tubercle density in hepatic region.

Abdomen subequal in length to carapace, pleura rounded cephaloventrally and angled caudoventrally. Lateral margins of terga angulate, lateral margins of second pleuron with deep furrow. Cephalic section of telson with 2 conspicuous spines in each caudolateral corner. Proximal podomere of uropod with distal spine on mesial lobe. Mesial ramus of uropod with median ridge tapering distally, terminating in median spine not extending beyond margin of ramus; laterodistal spine present. Distal margin of proximal segment of lateral ramus of left uropod with 1 large, fixed lateral spine, 1 large movable spine, and 15 small, immovable spines. Cephalomedian lobe of epistome subtriangular, rounded, anterior margins inflated; zygoma moderately arched; cephalolateral margins thickened, rounded at junction with endostyle; body of epistome possessing prominent cephalomedian fovea. Antennal scale broadest proximally; setiferous along mesial margin; lateral margin thickened and terminating in large spine. Right antennal scale 6.8 mm long, 3.6 mm wide. Antennae tips broken, right antenna extending only to posterior margin of carapace when adpressed. Dactyl of right chela apparently regenerated; all following descriptions from left chela. Mesial surface with one row of 6 well-defined tubercles. Palm length 74.6% palm width; depth 8.1 mm. Dorsal longitudinal ridge of dactyl with scattered row of 8 moderately-sized, well-defined tubercles; dactyl terminating in corneous spine. Weak dorsomedian ridge on fixed finger of propodus; small tuft of setae at fixed finger junction; scattered punctations throughout, absent of setae; terminating in corneous tip. Opposable margin of propodus from base consisting of 2 small tubercles, one large tubercle, 3 small tubercles, ending in sharply pointed tubercle. Opposable margin of dactyl from base consisting of 3 small tubercles, one enlarged tubercle, followed by 3 small tubercles. Carpus with prominent dorsal furrow, surface with scattered punctations; mesial margin with large, procurved spine approximately mid-length, with reduced proximal spine. Distodorsal surface of merus with 8 spines and spiniform tubercles, ventromesial ridge with 3 well-developed spines, ventrolateral ridge with 2 small spines. Hooks on ischium of third pereiopods. Form I gonopod as described in Diagnosis.

Allotypic Female ( Fig. 3 F , Table 3). Differing from the holotype in the following respects; TCL 32.7 mm, PCL 29.9 mm. Areola 2.8 times longer than wide, 34.6% of TCL (42.0% of PCL). Rostrum 1.3 times longer than width at base. Abdomen 25.2 mm in length. Hepatic spine present on either side of the cephalus. All following descriptions from right chela. Mesial margin with one well-defined row of 6 tubercles, one weak row of 3 small tubercles. Palm length (8.3 mm) 81.3% of palm width (10.2 mm). Palm depth 6.2 mm. Antennae intact, extending to fourth terga when adpressed. Antennal scale 6.7 mm long, 3.0 mm wide. Specimen lacks all male secondary sexual traits. Annulus ventralis as described in Diagnosis. First pleopods uniramous, reaching center of annulus ventralis when abdomen flexed.

Morphotypic Male, Form II ( Figure 3 D–E, Table 3). Differing from the holotype in the following respects; TCL 27.4 mm, PCL 21.8 mm. Areola 2.6 times longer than wide, 35.8% of TCL (45.0% of PCL). Rostrum 1.3 times longer than width at base. Abdomen 20.2 mm in length. All measurements and counts from right chela. Palm length (6.4 mm) 85.3% of palm width (7.5 mm). Palm depth 4.4 mm. Antennae intact, extending to base of telson when adpressed. Antennal scale 6.0 mm long, 2.4 mm wide. Gonopods reaching anterior margin of fourth pereiopod caudomesial boss. Central projection curved approximately 90° to shaft, rounded. Mesial process bulbous, tapering to rounded terminus, directed caudolaterally. Hook on ischium of third pereopod weakly developed, not extending to basioischial point.

Size. Form I male (n=13) TCL ranging in size from 23.8 mm to 36.5 mm (x̄=31.8, SD=3.54, SE=0.98). Form II male (n=14) TCL ranging in size from 21.5 mm to 33.7 mm (x̄= 26.7 mm, SD=4.51, SE=1.21). Female (n=37) TCL ranging in size from 18.5 mm to 42.3 mm (x̄= 29.6 mm, SD=5.59, SE=0.91). The largest individual observed was female measuring 42.3 mm TCL.

Color Notes. Cambarus franklini ( Fig. 4 ) carapace ground color olivaceous to maroon. Cephalic portion of carapace immediately anterior to cervical groove deep red, forming a small saddle; mandibular adductor scars dark red or mottled brown. Hepatic region olive to maroon, punctuated with cream-colored tubercles or spines. Rostrum ground color olivaceous to maroon, margins and acumen brown to red. Lateral margin of antennal scale red to brown, body of antennal scale cream to blue-green. Antennae and antennules cream to pink at base, becoming deeper red distally. Dorsal surface of chelae ranging from blue-green to olive, often mottled, tubercles on mesial margin cream-colored; ventral surface of chelae cream; mesial margin of ventral surface of chelae orange, conspicuous. Denticles on opposable surfaces of chelae cream-colored. Dorsal surface of carpus olivaceous to blue-green, region adjacent to and anterior of furrow deeply red; carpus spine red with cream-colored corneous tip.

Ventral surface of carpus light blue-green or cream. Ventral surface of merus olivaceous to blue-green, distal margin red, spines cream. Podomeres of pereopods light blue-green, distal margins of merus and carpus adjacent to joints red. Dorsal surface of abdomen ground color olivaceous, posterior margins of terga red, pleurons olivaceous to light blue-green; ventral surface of abdomen blue-green; swimmerets blue-green. Uropods blue-green, posterior margins red. Dorsal ridge of form I gonopod central projection amber; body of gonopod and mesial process creamcolored or tan, shaft cream to tan. Form II gonopod process cream to tan, shaft cream to blue-green. Annulus ventralis cream to blue-green.

Type Locality. Jacob Fork, in the vicinity of the SR 1904 bridge crossing leading into South Mountains State Park, 2.57 road km WNW junction with CR 1901 (N 35.5974, W 81.6014), Burke County, North Carolina. This section of the Jacob Fork is approximately 5 m in width, 0.25–0.5 m in depth, with a heterogeneous stream bottom primarily composed of gravel, cobble, and sand; secondarily composed of boulder, bedrock, and woody debris/ organic material. Holotype and allotype date of collection was 23 April 1985, morphotype date of collection was 1 July 1985.

Disposition of types. The holotype, allotype, morphotype, and 6 paratypes are deposited in the NCSM Nonmolluscan Invertebrate Collection (catalog numbers NCSM 90113 , 90115 , 90114 ; and 90098–90099, 90101– 90103, 90112 respectively). Two paratypes, including 1 MI and 1 F, are deposited in the USNM Invertebrate Zoology Collection ( USNM 1531724 , 1531725 ) .

Range and specimens examined. Cambarus franklini has been found only in the Henry and Jacob Forks in Burke and Catawba Counties, North Carolina, USA. Despite intensive sampling efforts, no additional populations of the species have been detected elsewhere in, or beyond, the Catawba River Basin ( Fig. 1 ).

NORTH CAROLINA: Burke County: 1 ) NCSM 2219 — Jacob Fork along CR 1904, N 35.5974 W 81.6014, 4 F, 1 M juv., 18 October 1984 , V. Schneider; 2) NCSM 2294 — Jacob Fork at bridge CR 1904, 1.6 rd mi WNW jct. CR 1901, N 35.5974 W 81.6014, 2 MI, 2 F, 2 M juv, 8 F juv., 23 April 1985, A.L. Braswell; 3) NCSM 2295 — Jacob Fork at bridge CR 1904, 1.6 rd mi WNW jct. CR 1901, N 35.5974 W 81.6014, 1 F ovig., 23 April 1985, A.L. Braswell; 4) NCSM 2369 — Jacob Fork at CR 1904, 1.3 mi WNW jct. CR 1901, N 35.5938 W 81.5962, 1 MII, 2 F, 4 M juv, 2 F juv; 1 July 1985, A.L. Braswell, A. Braswell & T. Howard; 5) NCSM 2372 — Jacob Fork , collected along CR 1904, 1.3 mi WNW jct. CR 1901, N 35.5974 W 81.6014, 1 MII, 3 F, 4 M juv, 1 July 1985, A.L. Braswell, A. Braswell & T. Howard; 6) NCSM 3187 — Jacob Fork at SR 1904, N 35.5974 W 81.6014, 3 M juv, 20 October 1984, D.R. Lenat, F. Winborne & J. Overton; 7) NCSM 3215 — Jacob Fork along SR 1904 (entrance rd. to South Mountains State Park ), N 35.5974 W 81.6014, 1 F ovig., 21 May 1996, A.L. Braswell & N. Murdock; 8) NCSM 3216 — Jacob Fork along SR 1904 (entrance rd. to South Mountains State Park ), N 35.5974 W 81.6014, 1 MI, 1 F; 21 May 1996, A.L. Braswell & N. Murdock; 9) NCSM 3645 —“ Jacob Fork ”, 2 MII, date and exact location unknown, C.M. Ramsey; 10) NCSM 90116 —“ Henry Fork and tribs,” 1 MI, 1 MII, 1 F juv., April 1988, D.R. Lenat; 11) NCSM 4445 — Jacob Fork at SR 1924, N 35.5906 -81.5671, 1 MI, 1 F juv., 6 May 1997, N. Medlin & B. Tracy; 12) NCSM 4446 — Henry Fork at SR 1916, N 36.6621 W 81.6042, 1 MII, 2 F juv., 6 May 1997, N. Medlin & B. Tracy; 13) NCSM 4480 —“ Jacob Fork ,” exact location and coll. unknown, 1 M juv, 18 August 1997; 14) NCSM 5173 —“ Burke County, NC”, exact location, date, and coll. unknown, 1 MII, 1 F; 15) NCSM 5205 — Jacob Fork at SR 1924, N 35.5906 W 81.5671, 1 MI, 3 F, 3 M juv, 2 F juv., 3 May 1999, N. Guthrie, D.R. Lenat, N. Medlin & B. Tracy; 16) NCSM 25698 — Jacob Fork at SR 1924, old NC 18, N 35.59083 W 81.56639, 1 M juv, 1 F juv, 2 May 2006, W.B. Crouch, B. Prusha & M. Walters; 17) NCSM 25810 — Jacob Fork , N 35.59047 W 81.56697, 1 MI, 4F, 1 F ovig., 21 April 2004, S.J. Fraley & J.W. Simmons; 18) NCSM 25811 — Jacob Fork , N 35.59047 W 81.56697, 1 MI, 21 April 2004, S.J. Fraley & J.W. Simmons; 19) NCSM 26198 — Little River off SR 1900, N 35.60669 W 81.59769, 1 MII, 1 F juv, 28 October 2007, B. Tracy, T. Butz, J. deBerardinis “ et al.”; 20) USNM 1531724 , 1531725 — Henry Fork at Old NC 18, N 35.66419 W 81.61581, 1 MI, 1 F, 26 October 2017, M.A. Perkins & S.G. Anderson; 21) NCSM 90086 — Henry Fork at River Rd. , N 35.66217 W 81.60412, 1 MI, 26 October 2017, M.A. Perkins & S.G. Anderson; 22) NCSM 90087–90088 — Jacob Fork at Rhoney Rd. , N 35.59346 W 81.55917, 1 MII, 1 F, 26 October 2017, M.A. Perkins & S.G. Anderson; 23) NCSM 90090–90093 — Henry Fork at Watershed Rd. , N 35.64406 W 81.67709, 2 F, 2 MI, 15 November 2017, M.A. Perkins & S.G. Anderson; 24) NCSM 90094–90097 — Jacob Fork at Hemlock Trail, South Mountains State Park , N 35.60246 W 81.62913, 2 F, 1 F juv, 1 MII, 15 November 2017, M.A. Perkins & S.G. Anderson; 25) NCSM 90098–90099 — Henry Fork at Miller Bridge Rd. , N 35.6792 W 81.4954, 1 F, 1 MI, 28 November 2017, M.A. Perkins & S.G. Anderson; 26) NCSM 90100 — Ivy Creek at Rich Mountain Rd. , N 35.63470 W 81.66090, 1 M juv, 12 February 2018, M.A. Perkins; 27) NCSM 90112 — Henry Fork at River Rd. , N 35.66068, W 81.60242, 2 MII, 1 F, 22 July 2016, M.A. Perkins, W.T. Russ, D.A. Crocker, S.L. Stevens.

Catawba County: 28) NCSM 90101–90104 — Jacob Fork at NC 127, N 35.64601 W 81.38123, 1 F, 2 MI, 15 November 2017, M.A. Perkins & S.G. Anderson; 29) NCSM 90105 — Henry Fork , N 35.69775 W 81.34447, 1 F, 22 July 2016, W.T. Russ, D.A. Crocker & S.L. Stevens; 30) NCSM 90106 — Henry Fork immediately downstream of Shuford Dam, pre-deconstruction, N 35.70135 W 81.34642, 1 F, 22 July 2016, W.T. Russ, M.A. Perkins, D.A. Crocker & S.L. Stevens; 31) NCSM 90107 — Henry Fork at Henry Fork River Park, N 35.70051 W 81.37945, 1 F, 22 July 2016, W.T. Russ, M.A. Perkins, D.A. Crocker & S.L. Stevens; 32) NCSM 90108 — Henry Fork at Old Shelby Rd., N 35.68364 W 81.40211, 1 F, 22 July 2016, W.T. Russ, M.A. Perkins, D.A. Crocker & S.L. Stevens; 33) NCSM 90109 — Jacob Fork at Old Shelby Rd., N 35.6147 W 81.4622, 1 MI, 29 October 2018, M.A. Perkins & L.W. Lovingood; 34) NCSM 90110 — Jacob Fork at NC 18, N 35.5975 W 81.5020, 1 MI, 29 October 2018, M.A. Perkins & L.W. Lovingood.

Conservation status. Cambarus franklini , sp. nov., is often locally abundant but narrowly distributed in only two streams in western North Carolina with an estimated current extent of <100 km 2 containing two known populations. The estimated population size for C. franklini is currently unknown. Threats to the species have not been fully assessed but likely include habitat degradation and diminished water quality from land use practices (primarily logging and agriculture) in some areas of the surrounding watershed. A species of non-native crayfish belonging to the genus Faxonius Crandall and Degrave, 2017 , has been reported from the lower Henry Fork immediately downstream of the recently-removed (c. 2016) Shuford Dam (NCWRC unpublished data). Based primarily on the species’ known narrow distribution, the species should be considered Threatened (T) following Taylor et al. (2007), Vulnerable (VU) using IUCN criteria (B2 a,b i-iv; 3.1), G2 (Imperiled) following NatureServe criteria.

Variation. Approximately 40% of the 64 individuals examined possess inconspicuous tufts of setae at the base of the opposable propodus. A small proportion of specimens examined (8%) possess 1–4 well-developed hepatic spines. Juveniles and sub-adults lack the robust chelae and sculptured denticles typical of adults. Juvenile coloration is typically olivaceous, however the characteristic bright red along the distal margins of the rami is present. Members of this species exhibit sexual dimorphism in reproductive structures. No geographic variation has been observed in this species.

Life History. Collections of C. franklini have occurred in January, April, May, July, August, September, October, and November. First form males have been observed in April, May, October, and November; second form males have been observed in all months sampled. Females in glare have been observed in November and January. Ovigerous females (n=2) have been observed in April and May. Young-of-year have not been observed. The species prefers 2 nd to 3 rd order streams and has been collected almost exclusively from beneath large cobbles (approx. 15 cm length) to small boulders (approx. 100 cm in length) in shallow riffles (0.1 m to 0.5 m depth) with moderate flow.

Crayfish associates. Several native stream-dwelling associate crayfish species occur with C. franklini , including Cambarus asperimanus Faxon, 1914 , C. johni , Cambarus species C and C. cf. howardi . Cambarus cf. dubius , a primary burrower, was observed in burrows along stream banks. Faxonius virilis , an invasive crayfish species, has been collected alongside C. franklini at one site.

Relationships and comparisons. Cambarus franklini shares morphological similarities with several described species as well as unnamed members of the genus Cambarus in the Catawba River basin. Cambarus species C represents at minimum one undescribed species found throughout the Catawba River basin and can be differentiated from C. franklini by having two well-defined rows of tubercles on the mesial margin of the palm, a more strongly cephalo-dorsally converged and shorter acumen, fewer (4–5) punctations through the narrowest section of the areola (5–7), reduced tuberculation on the denticles of the chelae, absence of hepatic spines, and generally mottled or consistently olivaceous coloration in life. Cambarus species C been collected at numerous sites with C. franklini , albeit in low numbers, but is typically less common in the middle reaches and mainstem Henry and Jacob Fork watersheds and more abundant in 1 st to 2 nd order tributaries, where C. franklini is typically absent. Cambarus johni is generally uncommon throughout the Henry and Jacob Fork watersheds and can be differentiated from C. franklini by possessing two well-defined rows of tubercles on the mesial margin of the palm, a more strongly cephalo-dorsally converged acumen, absence of hepatic spines, a wide and weakly-curved zygoma extending to at least the midline of the renal aperture, and conspicuous lateral stripes on either side of the abdomen in life. Additionally, Cambarus johni is typically found in woody debris and detritus along stream banks, instead of the riffles favored by C. franklini . Cambarus cf. howardi is another putatively undescribed species found throughout the lower Catawba River basin and can be differentiated from C. franklini by the absence of cervical and hepatic spines, presence of more strongly-inflated margins on the rostrum, and being generally smaller in size. It should be noted that while C. cf. howardi is considered sympatric with C. franklini , the species have been collected together at only two sites in the lower Henry Fork and Jacob Fork mainstems. Additionally, Cambarus franklini shares superficial similarities with C. aldermanorum and C. spicatus , both of which are often characterized by the presence of numerous hepatic spines. However, C. aldermanorum is easily characterized by the presence of a lanceolate rostrum with a conspicuously elongated acumen, a much narrower areola, and is not sympatric with C. franklini ; C. spicatus is distinguished by the presence of a short acumen delineated at its base by marginal spines or tubercles and is uncommonly found in the adjacent Broad River basin.

Etymology. The species epithet “ franklini ” is used in honor of Franklin D. Greybeard, a friend of author M. Perkins. The proposed common name, South Mountains crayfish, refers to the South Mountains region of western North Carolina, which harbors the entire known range of this species.

Common name. South Mountains crayfish.

Figures

FIGURE 1. Map of collection sites and the known range of Cambarus franklini. Red circles represent collection localities of C. franklini genetic tissues and specimens used in this study. Open (white) circles represent collection localities and/or observations of C. franklini specimens. Black diamonds represent sampling locations where C. franklini was not detected. Protected lands are represented by green shading; urban areas by gray shading. Inset: The Catawba River basin in NC (black shading) and the known occupied watersheds of C. franklini (red shading).

FIGURE 3. Cambarus franklini, new species: (A.) Lateral view of carapace; (B.) lateral and (C.) mesial view of form I gonopod; (D.) lateral and mesial view of form II gonopod; (F.) annulus ventralis; (G.) dorsal view of carapace; (H.) right antennal scale; (I.) Dorsal view of carpus and chelae; (J.) epistome. A–C, G–J from holotype; D–E from morphotype; F from allotype.

FIGURE 4. Cambarus franklini morphotype in life (photo credit: Carl E. Williams).