Cambarus (Jugicambarus) dubius Faxon, 1884

Loughman, Zachary J., Thoma, Roger F., Fetzner Jr, James W. & Stocker, G. Whitney, 2015, Cambarus (Jugicambarus) pauleyi, a new species of crayfish (Decapoda: Cambaridae) endemic to southcentral West Virginia, USA, with a re-description of Cambarus (J.) dubius, Zootaxa 3980 (4), pp. 526-546 : 528-534

Cambarus (Jugicambarus) dubius Faxon, 1884

Figs. 1 A–I, 2, 3

Cambarus dubius Faxon, 1884:114 . Faxon, 1885:70, pl. 4: fig. 3; pl. 8: figs. 7, 7'; Dewees, 1972:1, figs. 1b–l, 2c–h, 3, 4, 5b–h, 6–16.

Cambarus (Bartonius) carolinus: Ortmann, 1905b:120 , 135; Ortmann, 1906:394 [in part].

Cambarus carolinus: Ortmann, 1905a:393 ; Ortmann, 1906:451.

Cambarus carolinus dubius: Faxon, 1914:396 , 425.

Cambarus (Jugicambarus) dubius: Hobbs and Bouchard, 1973:62 ; Hobbs, 1974:18, fig. 60; Hobbs, 1989:22, fig. 78; Jezerinac et al., 1995:121, fig. 61.

Cambraus [sic] dubius: Peters, 1975 :iii [erroneous spelling].

Diagnosis. Body and eyes pigmented. Posterior region of rostrum concave and moderately to strongly deflected anteriorly. Rostral margins thickened, parallel to slightly converging at acumen. Rostral floor weakly excavated. Acumen distinctly triangular with prominent dorsally upturned spiniform tubercle at terminus. Areola obliterated. Cervical spines always absent. Mandibular, branchiostegal, and orbital regions of carapace with few welldeveloped tubercles. Postorbital ridges short; spiniform tubercle absent in both juveniles and adults. Suborbital angle obsolete. Carapace vaulted in lateral profile. Antennal scale widest in middle, 1.0–3.9 (x = 1.7, n = 50, SD = 0.6) times as long as wide. Total carapace length (TCL) 1.9–2.3 (x = 2.1, n = 50, SD = 0.1) times longer than width. Form I and II males possessing hook on ischium of third pereiopods 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 4–7 (x = 5.8, n = 50, SD = 0.8) tubercles, second dorsal row with 2–5 (x = 3.1, n = 50, SD = 0.7) tubercles. Tubercles do not extend from mesial surface to dorsal body of palm. Subpalmar tubercles absent on ventral surface at junction of dactyl with propodus. Dorsal ridge of dactyl consisting of several well developed scattered tubercles. Dorsomedian ridge of fixed finger of propodus pronounced. Ventral margin of propodus costate. Chelae lack defined lateral impression at junction of the fixed finger with basal propodus. Dactyl and fixed finger with sharp corneous tip forming spine. Form I male palm length 61.4–67.5% (x = 64.9%, n = 11, SD = 2.7%) of palm width, form II male palm length 29.9–34.5% (x = 32.8 %, n = 11, SD = 1.3%) of total propodus length; female dactyl length 31.0–37.7% (x = 34.2, n = 24, SD = 3.5%) of total propodus length. Single large carpal spine present. First pleopod of form I male with short terminal elements. Form I gonopod central projection not tapering distally; recurved> 90º to main shaft of gonopod, with distinct subapical notch. Mesial process directed 90° to shaft, bent cephalolaterally; inflated cephalically, tapering to distinct caudal point and extending beyond the apex of the central projection. Form II central projection curved 90° to shaft, with complete apex; rounded. Mesial process tapered, bulbous, directed caudolaterally. 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. Cephalic section sclerotized.

Description of holotypic form I male (MCZ-IZ-3631). ( Figs. 1 A–G, 2A–C). Body compressed laterally ( Fig. 1 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 33.5 mm; post orbital carapace length 30.2 mm. Areola length 14.8 mm: Areola 44.2% of TCL (49.0% of postorbital carapace length (PCL)). Rostrum weekly excavated; margins thickened, parallel and continuous to base of acumen where margins becomes subparallel; floor of rostrum with numerous punctations. Rostrum 1.6 times longer than wide. Acumen broad and triangular, ending in ventrally deflected corneous tip. Postorbital ridges short and well developed, lacking cephalic tubercles or spines ( Fig. 1 B). Suborbital angle subacute, lacking tubercle ( Fig. 1 B). Cervical spine absent. Mandibular, branchiostegal, and orbital regions of carapace punctated with well-developed tubercles; greatest tubercle density in hepatic region.

Abdomen supraequal in length to carapace, pleura rounded cephaloventrally, angled distoventrally. Lateral margin of terga angulate; lateral margin of second pleluron 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 5 immovable, small spines and 1 lateral, large, movable spine. Cephalomedian lobe of epistome subtriangular, zygoma moderately arched ( Fig. 1 C); cephalolateral margins thickened, forming sharp angle at junction with endostyle ( Fig. 1 C). Body of epistome possessing prominent cephalomedian fovea. Antennal scale broadest in middle ( Fig. 1 D); lateral margin thickened, terminating in large corneous spine; mesial margin setiferous Right antennal scale 3.3 mm long, 1.5 mm wide. Tip of right antenna reaching posterior portion of carapace when adpressed.

Mesial surface of right chela with 2 rows of tubercles; mesial most row with 5 tubercles, second dorsal row with 3 tubercles ( Fig 1 E). Palm length 69.7% of palm width; depth of palm 5.9 mm. Ventral surface of palm containing no subpalmar tubercles. Dorsal longitudinal ridge of dactyl developed and possessing moderate sized tubercles ( Fig. 1 E); dactyl terminating in large corneous spine. Dorsomedian ridge of fixed finger of propodus pronounced. Propodus terminating in sharp, corneous tip. Lateral impression at junction of fixed finger and propodus absent. All measurements and counts from right chela.

Carpus with prominent dorsal furrow; remainder of surface with some setiferous punctations; mesial margin with 1 large, procurved spine near midlength. Distodorsal surface of merus with 8 spiniform tubercles; ventrolateral ridge with 4 small spines and large, corneous distal spine; ventromesial ridge with 2 well-developed spines; ventrolateral margin of ischium with 1 small, spiniform tubercle. Hook on ischium of third pereiopods only ( Fig. 1 F); hook gently curved at apex, overarching basioischial joint, not opposed by tubercle on basis. Form I gonopod as described in diagnosis ( Fig. 1 G); tip reaching anterior margin of fourth caudomesial boss when abdomen is flexed.

Color. Carapace ground color orange to orange-red ( Fig. 3 ); posterior margin of carapace orange. Hepatic and antennal region of carapace punctuated with orange, white, or cream tubercles. Postorbital ridge color orange to orange-red. Rostrum margins and acumen orange, rarely orange-red. Cephalic section of carapace immediately anterior to and including cervical groove orange, orange-red, occasionally cream; mandibular abductor scars ranging from orange to orange-red. Lateral margin of antennal scale light orange to orange; body of antennal scale orange to amber. Antennal flagellum and antennules light orange; dorsal surface of lamellae pink to orange; ventral surface cream to orange. Dorsal surface of chelae orange to orange-red with light orange highlights; mesial, second dorsal row, and dorsal surface of dactyl tubercles orange, orange-red or yellow-orange. Denticles on opposable surfaces of fingers cream, light orange, or amber. Ventral surface of chelae orange or cream. Dorsal surface of carpus orange, orange-red or amber; occasionally light orange; region adjacent to and including furrow orange to orange-red; carpus spine light orange or cream. Merus orange to orange-red, yellow orange or amber. Podomeres of pereiopods orange, orange-red, or cream; joints of pereiopodomeres cream or white. Dorsal and dorsalateral surface of abdomen same color as carapace; anterior region of abdomen with slight orange-red tint; tergal margins red-orange to reddish brown. Uropods orange to orange-red with orange yellow tint; margins white to cream. Ventral surface of abdomen and carapace white or 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.

Range and specimens examined. Jezerinac et al. (1995), in their monograph on West Virginia crayfishes, were the first to delineate the range of what we here define as nominate C. dubius . Specifically, the distribution of Jezerinac et al.’s (1995) “ orange or red ” color morph, which is our nominate form, was stated as “… found in the Allegheny Mountain Physiographic Provinces in the upper northcentral part of the state ”. Though not specifically discussed, the distribution of a single “ red ” color morph population falls outside the distribution of their “ orange ” morph., with another falling within the nominate form’s distribution. Jezerinac et al. (1995) state in the latter section of the “ orange and red color” morph distribution section “two populations were found in the Ridge and Valley Physiographic province; one in Grant and one in Monroe County”. Red colored C. aff. dubius were collected recently by ZJL on the banks of Wolf Creek, Monroe County WV, and are not included here in our morphological analysis. These animals differ markedly from nominate C. dubius , and are not representative of the nominate form. Animals reported from Grant County, West Virginia by Jezerinac et al. (1995) do fall within our circumscription of C. dubius s.s., and are thus included within the distribution of the nominate form defined herein. The range of Cambarus dubius in West Virginia was recently re-evaluated by Loughman and Welsh (2013) to include all populations possessing orange carapaces and abdomens, occurring at the junction of the Appalachian Plateau and western front of the Allegheny Mountains in Barbour, Upshur and Taylor counties, the Allegheny Mountains of Preston and Randolph counties, and the western junction of the Ridge and Valley and eastern Allegheny Front in Grant and Mineral counties, West Virginia. These eastern most populations continue into Garret and Allegheny counties Maryland in a northeastern direction, and represent the species distribution in that state ( Kilian et al. 2010; Loughman 2010a). Ortmann (1905a; 1906) defined the range of C. dubius s.s. (but as C. carolinus ) in Pennsylvania, which comprises the northern-most populations of the species, which still holds true today (ZJL and D. Lieb, personal observations). In Pennsylvania, the species occurs solely in the Allegheny Mountain physiographic province, with the western extent of the species range delineated by Chestnut Ridge, and the eastern extent terminating along the eastern Allegheny Front at the junction of the Alleghenies and the Ridge and Valley. It is our recommendation that only crayfish meeting the diagnosis described herein, and occurring within this newly defined distribution ( Fig. 4 ), be referred to as C. dubius s.s. All other populations previously considered C. dubius which fall outside the distribution defined above should be referred to as Cambarus aff. dubius , pending future taxonomic study. Specific locality information used to generate Fig. 4 is provided in Appendix I.

Conservation Status. Cambarus dubius s.s. should be listed as Currently Stable (CS) according to the American Fisheries Society criteria ( Taylor et al. 2007), and assigned a G4 ranking according to the global conservation criteria ( Masters 1991) for conservation listing. Cambarus dubius s.s. should be listed as Least Concern (LC) using the International Union for the Conservation of Nature ( IUCN 2001) criteria due to it maintaining several stable populations across its range.

Figures

FIGURE 1. Illustration of various morphological features of Cambarus dubius sensu stricto, as herein defined. (A.) lateral view of carapace; (B.) dorsal view of carapace; (C.) epistome; (D.) antennal scale; (E.) dorsal view of distal podomere of right cheliped of form I male; (F.) ischial hook of form I male; (G.) lateral (left) and mesial (right) view of left first gonopod of form I male; (H.) annulus ventralis; (I.) lateral (left) and mesial (right) view of form II male gonopod. A – G from holotype; H from WLU 2050 b (female); I from WLU 2050 a (form II male).

FIGURE 3. Cambarus dubius sensu stricto. A recently collected form I male from the type locality, Terra Alta (= Cranberry Summit), Preston County, West Virginia showing typical life colors.

FIGURE 4. Known range of Cambarus dubius sensu stricto in Maryland, Pennsylvania and West Virginia.