Cambarus nodosus R. W. Bouchard & Hobbs 1976

Cambarus (Jugicambarus) nodosus

Cambarus carolinus.—Holt, 1968:32.

DIAGNOSIS.—Body and eyes with pigment, latter small. Rostrum without marginal spines or tubercles. Areola 5.0 to 13.6 times as long as broad and constituting 33.9 to 41.4 percent of total length of carapace (38.2 to 46.5 percent of postorbital carapace length) with 2 to 4 punctations across narrowest part. Cervical spine lacking, although small rounded tubercle present. Hepatic spines absent; branchiostegal tubercle small and rounded; suborbital angle moderately to well developed. Postorbital ridge rather well developed without cephalic tubercle. Antennal scale longer than broad, broadest slightly distal to midlength. Chela with 2 rows of tubercles along mesial margin of palm, mesialmost subserrate, secondary row uneven; scattered tubercles over dorsomesial half of palm; well-defined longitudinal ridges on dorsal surface of fingers, less obvious ones on ventral side; lateral surface of fixed finger weakly costate. Hook on ischium of third pereiopod of first form male overreaching basioischial articulation and not opposed by tubercle on basis. First pleopod of first form male with central projection corneous, bladelike, tapering, bearing distinct, small subapical notch, and recurved at angle of approximately 90 degrees to shaft of appendage; mesial process tumescent, tapering to acute tip and directed caudally at angle of approximately 90 degrees. Both elements of first pleopod appreciably longer than cephalocaudal diameter of shaft of appendage. Annulus ventralis asymmetrical, subcylindrical and movable; cephalic half bearing longitudinal median trough between anteriorly converging ridges, and caudal half with sinuate dextral or sinistral sinus. Caudal wall of annulus elevated. First pleopod of female uniramous and reaching at least midlength of annulus when abdomen flexed.

HOLOTYPIC MALE, FORM I.—Body subovate, depressed (Figure 3a,j). Abdomen narrower than thorax (12.9 and 14.9 mm). Greatest width of carapace greater than height at caudodorsal margin of cervical groove (14.9 and 12.0 mm). Areola 7.1 times as long as wide with 3 punctations across narrowest part; length of areola 37 percent of entire length of carapace (42.3 percent of postorbital carapace length). Rostrum with thickened, slightly concave, subparallel margins devoid of marginal spines or tubercles. Acumen set off from basal portion of rostrum, with concave, oblique, slender margins, and terminating in small upturned tubercle. Rostrum excavate dorsally, especially deep anteriorly, with submarginal punctations and few scattered ones basally. Ventrolateral margin of rostrum with long, thick setae except at apex of acumen. Postorbital ridges moderately well developed, shallowly grooved dorsolaterally and lacking cephalic tubercle. Suborbital angle moderately strong, lacking corneous tip; branchiostegal spine represented by small tubercle. Cervical spine absent although represented by very small rounded tubercle. Hepatic area and lateral portion of branchiostegite tuberculate; dorsal surface of carapace punctate.

Abdomen longer than carapace (29.3 and 28.9 mm); pleura of moderate length with caudoventral extremities subangular. Cephalic section of telson with marginal spine and submarginal movable spine in each caudolateral corner and partially delimited from caudal section by paired oblique incisions. Basal podomere of uropod with spine extending over mesial ramus; lateral ramus with median and submedian ridges, former terminating in acute spine at transverse flexure. Proximal portion of lateral ramus with row of small spines distally and large, submarginal movable spine at caudolateral corner. Mesial ramus of uropod with median ridge terminating distally in premarginal acute spine; lateral margin with distolateral acute spine. Dorsal surface of telson and uropod lightly setiferous and fringed caudally.

Cephalic lobe of epistome (Figure 3g) rounded with small cephalomedian projection and slightly irregular, thickened cephalolateral margins. Main body of epistome with very shallow median fovea and pair of obliquely disposed slitlike fossae immediately cephalic and subparallel to thickened, slightly arched epistomal zygoma; lateral extremities with several small tubercles. Proximal segment of antennule with small spine on ventral surface near midlength. Antennae broken. Antennal scale (Figure 3i) broadly declivous, broadest distal to midlength; thickened lateral portion terminating in prominent, acute, corneous-tipped spine projecting anteriorly beyond tip of rostrum.

Right chela (Figure 3l) about 2 times as long as broad (21.9 and 11.0 mm), inflated, especially proximolaterally; mesial margin of palm with primary subserrate row of 7 tubercles and uneven secondary row of slightly smaller tubercles dorsolateral to primary row; scattered tubercles over dorsomesial half of palm; distoventral surface of palm with 2 large, swollen tubercles at base of dactyl, mesial one with small, corneous, rounded tip. Lateral surface of propodus weakly costate with row of punctations rendering proximolateral base slightly impressed dorsally, less so ventrally; dorsal and ventral surfaces of fixed finger with distinct submedian ridges flanked by setiferous punctations; opposable surface with row of 5 tubercles along proximal half, third from base largest; distal tubercle moderately acute, others knoblike; additional acute tubercle present on lower level near base of distal fourth; opposable surface also with row of minute denticles extending distally from fourth tubercle from base, row interrupted only by fifth. Dorsal and ventral surfaces of dactyl with median longitudinal ridges flanked by setiferous punctations; opposable margin with row of 7 tubercles situated in slight excavation, proximal 3 rounded (basalmost largest), followed by 2 moderately acute and 2 acute distal ones; row of denticles, broken by tubercles, extending from third tubercle to distal end of finger. Fingers terminating in large, acute, corneous spines.

Carpus longer than broad (9.2 and 6.0 mm) with deep oblique furrow dorsally; mesial surface with large spine near midlength and small tubercle near proximal base of latter; 3 rounded tubercles on dorsomesial surface; distoventral margin with 3 rounded tubercles; podomere otherwise punctate.

Upper surface of merus with 3 rounded subdistal tubercles and 11 along crest of podomere; ventral surface with lateral row of 5 subacute spines, and mesial row of 11 subacute ones, both rows decreasing in size proximally. Ischium with row of 3 small tubercles on ventromesial margin.

Hook on ischium of third pereiopod only (Figure 3h); hook simple, overreaching basioischial articulation and not opposed by tubercle on basis. Coxa of fourth pereiopod with prominent caudomesial boss, that of fifth without prominence. (See “Measurements”.)

First pleopods (Figure 3b,d,f) reaching caudal portion of coxae of third pereiopods when abdomen flexed. (See “Diagnosis” for description.)

ALLOTYPIC FEMALE.—Differing from holotype in following respects: areola constituting 37.7 percent of entire length of carapace (43.1 percent of postorbital carapace length) and 5.8 times as long as broad. Cephalic lobe of epistome triangular. Palm of right chela with primary row of 8 tubercles. Mesial surface of carpus with horizontal row of 3 tubercles proximal to large spine; dorsomesial surface with 3 very small tubercles (6 on left cheliped); distoventral surface with cluster of 5 tubercles. Upper surface of merus of right cheliped with 2 subdistal rounded tubercles and 10 (8 on left) along crest of podomere; ventrolateral margin with row of 7 spines on both chelipeds; ventral surface with more acute spines. (See “Measurements”.)

Sternum between third and fourth pereiopods broadly V-shaped and moderately deep. Annulus ventralis (Figure 3k) with cephalic half bearing median longitudinal trough flanked by ridges converging anteriad; caudal half with sinistral sinus. Caudal wall of annulus elevated, especially caudolaterally. First pleopod uniramous and reaching at least midlength of annulus when abdomen flexed.

MORPHOTYPIC MALE, FORM II.—Differing from holotype in following respects: rostrum less excavate anteriorly; ventral margin with setae sparse on sides of rostrum and lacking on most of acumen; cephalic tubercle more spiniform. Areola constituting 37.9 percent of entire length of carapace (43.8 percent of postorbital carapace length) and 7.1 times as long as broad with 2 punctations across narrowest part. Palm on left chela with primary row of 6 tubercles. Mesial surface of carpus of both left and right chelipeds with horizontal row of 3 tubercles proximal to large spine; dorsomesial surface of both with 2 tubercles. Upper surface of merus of right cheliped with 2 rounded subdistal tubercles and 11 along crest of both right and left, latter with additional laterally disposed tubercle; ventrolateral margin of merus of left cheliped with row of 6 spines, and ventromesial margin of left and right with row of 10 and 9, respectively. Caudolateral corners of epistome especially elevated. Propodus of chela with third and fourth tubercles from proximal end more acute.

Hook on ischium of third pereiopod much reduced, not reaching basioischial articulation. Boss on coxa of fourth pereiopod somewhat smaller and less sharply defined. (See “Measurements”.)

First pleopods (Figure 3c,e) of uniform texture, neither element corneous, central projection heavier, rounded caudally, and recurved at angle of approximately 90 degrees to shaft of appendage; mesial process tumescent, terminating cephalically in acute tip and directed caudally at angle of approximately 90 degrees. Both elements of first pleopod appreciably longer than cephalocaudal diameter of shaft of appendage.

COLOR

Cambarus nodosus is a species of crayfish in the family Cambaridae. It is found in North America.

The IUCN conservation status of Cambarus nodosus is "LC", least concern, with no immediate threat to the species' survival. The IUCN status was reviewed in 2010.