Procambarus clemmeri Hobbs 1975

Procambarus (Pennides) clemmeri

DIAGNOSIS.—Pigmented, eyes well developed. Rostrum with marginal spines, median carina absent. Carapace with 2 pairs of cervical spines. Areola 3.8 to 5.0 times longer than broad and constituting 24.1 to 26.8 percent of total length of carapace (35.6 to 38.9 percent of postorbital carapace length). Suborbital angle very small. Postorbital ridge with cephalic spine. Hepatic area without spines. Antennal scale approximately 2.8 times longer than wide, broadest proximal to midlength. Ischia of third and fourth pereiopods of first form male with hooks, that on third far overreaching basioischial articulation and that on fourth opposed by prominent distal tubercle on basis; coxa of fourth pereiopod with prominent subvertical boss. First pleopod of first form male reaching coxa of third pereiopod, asymmetrical, and provided with subapical setae; distal extremity bearing long prominent caudolaterally directed subspiculiform, weakly sclerotized mesial process; acute, also weakly sclerotized, distally directed cephalic process situated on cephalomesial side of central projection and projecting distally beyond other terminal elements; acute caudally directed caudal process at caudolateral base of central projection; and prominent corneous, beaklike central projection directed caudally. Annulus ventralis more than twice as broad as long, partially hidden by tuberculiform processes extending caudally from sternum immediately cephalic to annulus; ventral surface with paired, elevated (ventrally), cephalolateral arcs separated cephalically by short longitudinal submedian trough; arcs subtending oval submedian prominence; sinus originating in trough, turning caudolaterally in broad curve before returning to median line, there turning caudolaterally and ending on caudal slope of submedian elevation. Postannular plate approximately half as wide as annulus and only slightly more than half as long with cephalic arc of punctations. First pleopod present in female.

HOLOTYPIC MALE, FORM I.—Cephalothorax (Figure 6a,j) subovate, compressed. Abdomen narrower than thorax (13.8 and 15.8 mm). Greatest width of carapace subequal to height at caudodorsal margin of cervical groove. Areola 4.2 times longer than wide with 5 punctations across narrowest part. Cephalic section of carapace almost 3 times as long as areola, length of latter 25.2 percent of entire length of carapace (38.8 percent of postorbital carapace length). Rostrum with slender slightly convergent margins narrower at base than at level of cephalic margin of carapace; margins provided with well-developed spines, and long acumen overreaching antennular peduncle; dorsal surface shallowly excavate with many small setiferous punctations in addition to usual submarginal row. Subrostral ridges weak and evident in dorsal aspect only in caudal orbital region. Post-orbital ridges well developed, grooved dorsolateraly, and terminating cephalically in strong spines. Two pairs of strong cervical spines present with row of small tubercles extending dorsally above them. Suborbital angle very small but subacute. Branchiostegal spine prominent. Surface of carapace punctate dorsally and dorsolaterally, granulate laterally, and tuberculate cephaloventrally.

Abdomen longer than carapace (39.5 and 36.4 mm). Pleura of third through fifth abdominal segments with rounded cephaloventral and ventral margins, latter tapering to distinct caudoventral angles. Cephalic section of telson with 3 spines in each caudolateral corner. Cephalic lobe of epistome (Figure 6i) subcordiform with prominent angular projections cephalolaterally; margins not strongly elevated; fovea trenchlike and deep. Ventral surface of proximal podomere of antennular peduncle with strong spine at midlength. Antenna, with spines on basis, ischium, and merus, extending caudally to midlength of telson. Antennal scale (Figure 6l) 2.8 times longer than wide, widest proximal to midlength; lamellar portion about twice width of thickened lateral part.

Third maxilliped extending anteriorly to level of midlength of rostrum; ischium with distolateral extremity acute and ventral surface with lateral half bearing scattered setiferous punctations; exopod reaching base of distal third of merus.

Right chela (Figure 6n) subovate in cross section, not strongly depressed. Mesial surface of palm with row of 8 tubercles subtended ventrally by irregular row of 6 and dorsally by row of 10; remainder of palm tuberculate. Both fingers bearing low, rounded, median longitudinal ridges flanked proximally by few tubercles, rapidly replaced by setiferous punctations extending to base of corneous tip of finger. Opposable margin of fixed finger with row of 6 small tubercles along proximal half and prominent tubercle on lower level at base of distal two-fifths; band of minute denticles, ventral to row of tubercles, extending almost from base of finger to base of corneous tip, band distinctly broader distal to large tubercle on lower level. Opposable margin of dactyl with row of 10 small tubercles along proximal three-fifths and larger 1 or 2 on lower level at end of proximal fourth of finger; band of minute denticles extending almost entire length of finger, band broader distal to larger 1 or 2 tubercles; mesial margin of finger with 2 or 3 moderately prominent tubercles along proximal fourth.

Carpus of cheliped longer than broad, conspicuously tuberculate dorsomesially and mesially and with few small tubercles dorsolaterally and ventrally; two spikelike tubercles on mesial surface, one distomesially and other near midlength; ventral surface with usual 2 tubercles on distal margin spiniform and with longitudinal row of 4 or 5 smaller tubercles situated proximal to more mesial marginal tubercle.

Merus of cheliped strongly tuberculate dorsally and ventrally and weakly so laterally and mesially; 2 premarginal spiniform tubercles dorsally; ventral surface with mesial row of 14 or 17 tubercles, distalmost spikelike, and lateral row of 12, of which 3 or 4 spikelike; distal, ventrolateral angle with strong spine. Ischium with row of 5 tubercles ventromesially, proximal 3 spiniform and larger than distal 2.

Hooks on ischia of third and fourth pereiopods (Figure 6m) simple, that on third longer and distinctly overreaching basioischial articulation; that on fourth opposed by strong knoblike tubercle on distal extremity of basis. Coxa of fourth pereiopod with strong, vertically disposed boss caudomesially. Coxa of fifth pereiopod with moderately conspicuous boss (slender projection) on caudomesial angle.

Sternum between second, third, and fourth pereiopods rather deep with conspicuous mat of plumose setae extending mesially from ventrolateral margins.

First pleopods (Figure 6c,f,g,h,k) as described in “Diagnosis.” In addition, proximomesial base of sinistral member produced in subcorneal prominence. Uropod with both lobes of basal podomere bearing spines; distomedian spine on mesial ramus withdrawn some distance proximal to distal margin of ramus.

ALLOTYPIC FEMALE.—Differing from holotype in following respects: row of tubercles dorsal to cervical spine not nearly so prominent; suborbital angle virtually vestigial; mesial surface of palm of chela with row of 6 tubercles subtended dorsally by row of 8, ventral row absent, replaced by few scattered tubercles; opposable margin of fixed finger of chela with 5 small tubercles in proximal half and single row of minute denticles extending from base to level of large, more ventral tubercle, and with 2 rows of denticles continuing from there to base of corneous tip of finger; opposable margin of dactyl with single row of 10 tubercles, and single row of minute denticles extending almost entire length of finger; carpus with only 3 tubercles in row extending proximally from mesial tubercle on ventrodistal margin; merus with ventrolateral row of 5 or 7 tubercles, 2 or 3 spikelike, and ventromesial row of 12, 5 or 6 of which spikelike; ischium of cheliped with only 3 tubercles on ventromesial margin.

Annulus ventralis (Figure 6b) moderately deeply embedded in sternum, convex cephalically and with almost horizontal caudal margin (see “Diagnosis” for details). Sternum cephalic to annulus with submedian longitudinal fissure, caudally projecting prominences, and tubercles. Postannular plate about one-half as wide and one-half as long as annulus, not strongly elevated, and with general outline similar to that of annulus, its ventral surface bearing arc, convex cephalically, of punctations. First pleopod extending to midlength of annulus when abdomen flexed. (See “Measurements.”)

MORPHOTYPIC MALE, FORM II.—Differing from holotype in following respects: suborbital angle reduced as in allotype; mesial surface of palm of chela with 6 or 7 tubercles flanked by ventral row of 4 and dorsal one of 6 or 7; opposable margin of fixed finger with row of 5 tubercles and that of dactyl with 6; carpus with only 3 or 4 tubercles in row extending proximally from mesial tubercle on ventrodistal margin; merus with ventrolateral row of 9 tubercles, 2 spikelike, and ventromesial row of 13, 2 or 3 spikelike; ischium of cheliped with 3 or 5 tubercles on ventromesial margin. Hooks on ischia of third and fourth pereiopods much reduced, neither overreaching basioischial articulation, and opposing tubercle on basis of fourth not evident. Boss on coxa of fourth pereiopod conspicuously reduced; that on fifth less so. First pleopod (Figure 6d,e) without corneous elements, all reduced except cephalic process, latter hooding and obscuring much of central projection; juvenile oblique suture present, conspicuous on lateral surface.

COLOR

Procambarus (Pennides) clemmeri Hobbs

Procambarus (Pennides) clemmeri Hobbs, 1975:19, fig. 6.

Procambarus clemmeri.—Hobbs, 1975:24.

TYPES.—Holotype, allotype, morphotype, USNM 145607, 145608, 145609 (male I, female, male II); paratypes, USNM.

TYPE LOCALITY.—Tributary to the Jourdan River, 8.7 miles (13.9 km) southeast of the Pearl River-Hancock County line on State Route 43, 4.3 miles (6.9 km) northwest of the junction of State routes 43 and 603 north of kiln, Hancock County, Mississippi.

RANGE.—From the Pearl River to the Escatawpa River basin in southern Mississippi and Alabama.

HABITAT.—Streams.