Procambarus marthae Hobbs 1975

Procambarus (Orlmannicm) marthae

DIAGNOSIS.—Pigmented, eyes well developed. Rostrum without marginal spines or tubercles, median carina absent. Carapace without or with very weak cervical spine. Areola 11 to 28 times longer than broad and constituting 32.7 to 36.3 percent of total length of carapace (42.7 to 44.7 percent of postorbital carapace length). Suborbital angle obtuse. Postorbital ridges without cephalic spine or tubercle. Hepatic area without spines. Antennal scale approximately twice as long as wide, broadest distal to midlength. Ischia of third and fourth pereiopods of first form male with simple hooks, both hooks overreaching basioischial articulation and neither opposed by tubercle on basis; coxa of fourth pereiopod with weakly developed caudomesial boss, that of fifth with small, tuberculiform one. First pleopod of first form male reaching coxa of third pereiopod, asymmetrical, provided with subapical setae, and lacking distinct shoulder on cephalic surface; prominent caudal bulge present in distal fourth; distal extremity bearing slender, distally acute, and somewhat caudolaterally directed mesial process extending beyond other terminal elements; caudal process, thumblike in lateral aspect, directed cephalodistally, and situated immediately caudolaterally to prominent, corneous, clawlike (arched cephalically), distally directed central projection; cephalic process lacking. Annulus ventralis slightly less than 1.5 times broader than long, symmetrical with median elevation (ventrally) bearing cephalomedian longitudinal furrow; sinus originating in caudal portion of furrow and extending caudally in sinuous curve, terminating before reaching midcaudal margin of annulus. Sternum cephalic to annulus without tubercles or caudal projections. Postannular plate subsemicircular in outline, unadorned, slightly less than one-third as long, and not quite two-thirds as wide as annulus. First pleopod present in female.

HOLOTYPIC MALE, FORM I.—Cephalothorax (Figure 2a,k) subovate, slightly compressed. Abdomen narrower than thorax (10.0 and 12.1 mm). Greatest width of carapace slightly greater than height at caudodorsal margin of cervical groove. Areola 28.0 times longer than wide with 1 punctation in narrowest part. Cephalic section of carapace about 1.8 times as long as areola, length of latter 35.3 percent of entire length of carapace (43.9 percent of postorbital carapace length). Surface of carapace punctate dorsally, granulate laterally. Rostrum deflected ventrally, with slender subparallel margins to level of midlength of penultimate podomere of antennule, there rather suddenly converging and terminating in small subtriangular tip at level of base of ultimate podomere of antennular peduncle; margins neither thickened nor provided with spines or tubercles; dorsal surface subplane with many setiferous punctations (those in basal portion of rostrum larger and deeper) in addition to usual submarginal row. Subrostral ridge weak and evident in dorsal aspect along caudal fourth of rostrum. Postorbital ridge well developed, grooved dorsolaterally, and gently merging cephalically with carapace, lacking spines or tubercles. Suborbital angle broad and obtuse. Branchiostegal spine small and acute. Cervical spine absent and no tubercle along caudal side of cervical groove conspicuously larger than others.

Abdomen longer than carapace (26.0 and 24.4 mm). Pleura of third through fifth segments broadly rounded ventrally and lacking angles. Cephalic section of telson with 2 spines in each caudolateral corner. Cephalic lobe of epistome (Figure 2g) rounded laterally, subtruncate cephalically, and with cephalolateral angles and cephalomedian projection; distinct but shallow fovea present. Ventral surface of proximal podomere of antennular peduncle with strong spine at midlength. Antenna with comparatively weak spiniform tubercles on basis and ischium; flagellum extending to midlength of sixth abdominal tergum. Antennal scale (Figure 2i) about twice as long as broad, widest distal to midlength; greatest width of lamellar portion slightly more than twice width of thickened lateral part.

Third maxilliped extending cephalically slightly beyond tip of rostrum; ischium with distolateral extremity bearing small angular prominence, and ventral surface with lateral half bearing conspicuous punctations studded with plumose setae, latter more abundant proximally than distally; distolateral angle with small tubercle; exopod reaching distal end of merus.

Right chela (Figure 2n) subovate in cross section, not strongly depressed. Mesial surface of palm with irregular row of 8 tubercles subtended by additional rows dorsally and ventrally; squamous tubercles scattered over most of palm and basal portions of both fingers; usual larger tubercle present ventrally opposite base of dactyl. Both fingers with low longitudinal ridges dorsally, flanked proximally by few tubercles and more distally by setiferous punctations; ridges on ventral surface of fingers well developed. Opposable margin of fixed finger with row of 10 tubercles (second from base largest) along proximal half, and large subacute, distinctly corneous tubercle on lower level at base of distal third; band of minute denticles extending almost entire length of finger between row of tubercles and larger, more ventral tubercle. Opposable margin of dactyl with dorsal row of 14 tubercles and ventral row (beginning more distally) of 4 tubercles along proximal two-fifths of finger, rows flanking band of minute denticles extending along almost entire margin; mesial surface with row of tubercles, decreasing in size distally, along proximal third of finger.

Carpus of cheliped longer than broad with shallow oblique groove dorsally, tuberculate mesially and dorsomesially; mesial surface with 2 tubercles dorsodistally and 3 along proximal half somewhat larger than others (larger tubercles not distinguishable in Figure 2n because of angle illustrated); ventral surface with usual 2 tubercles on distal margin and 3 or 4 additional ones ventromesially; otherwise, surface of podomere with setiferous punctations.

Merus tuberculate dorsally, distomesially, and ventrally; 2 dorsal preapical tubercles larger than others on dorsal surface; ventral surface with mesial row of 17 tubercles and lateral one of 9, also additional tubercles flanking rows. Ischium with row of 4 tubercles ventromesially.

Hooks on ischia of third and fourth pereiopods (Figure 2m) simple, both overreaching basioischial articulation, neither opposed by tubercle on corresponding basis. Coxa of fourth pereiopod with rather weak, rounded, caudomesial boss. Coxa of fifth pereiopod with tuberculiform boss on caudomesial angle.

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

First pleopods (Figure 2b,f,h,j,l) as described in “Diagnosis.” In addition, proximomesial lobe of sinistral member in form of broad, rounded, somewhat flattened prominence. Uropod with both lobes of basal podomere bearing acute spines; distomedian spine on mesial ramus situated much proximal to distal margin of ramus.

ALLOTYPIC FEMALE.—Differing from holotype in following respects: rostral margins with major contraction proximal to level of distal end of proximal podomere of antennule; subrostral ridges evident in dorsal aspect along basal half of rostrum; cervical spines represented by 1 or 2 very small tubercles, both larger, however, than others in immediate vicinity; cephalic lobe of epistome with more prominent angular cephalolateral projections; opposable margin of fixed finger of chela with row of 11 tubercles, that of dactyl with 2 rows virtually indistinguishable but with linear series of 18 tubercles along proximal three-fifths of finger, fifth from base largest; both fingers with narrow (rarely more than 2 abreast) band of minute denticles extending almost entire opposable length; mesial surface of merus of cheliped with single prominent dorsodistal tubercle and 2 prominent ones near midlength, ischium of cheliped with ventromesial row of 4 tubercles. (See “Measurements.”)

Annulus ventralis (Figure 2d) shallowly embedded in sternum, convex cephalically and caudally (see “Diagnosis” for details). Sternum cephalic to annulus without caudally projecting prominences or tubercles. Postannular plate (Figure 2d) as described in “Diagnosis.” First pleopod almost reaching midlength of annulus when abdomen flexed.

MORPHOTYPIC MALE, FORM II.—Differing from holotype in following respects: contour of rostrum similar to that of allotype; epistome subrhomboidal with lateral margins more nearly straight than in holotype; caudosinistral corner of cephalic section of telson with 3 spines; ischium of third maxilliped conspicuously hirsute; opposable margin of fixed finger of chela with row of 9 tubercles (third from base largest); opposable margin of dactyl with dorsal row of 8 tubercles and ventral one of 7; minute denticles on both fingers in narrower row (as in allotype) than in holotype; cluster of plumose setae at ventromesial base of fixed finger; tubercles on mesial surface of merus of left cheliped arranged as in allotype; ventrolateral row of 12 tubercles present on cheliped, and ischium with ventromesial row of 5. (See “Measurements.”)

First pleopod (Figure 2c,e) similar in most respects to holotype; however, neither reduced central projection nor vestigial caudal process corneous, and mesial process comparatively shorter and more conical. Hooks on ischia of third and fourth pereiopods much reduced, but bosses on coxae of fourth and fifth pereiopods little different in size from those of holotype.

COLOR

Procambarus (Ortmannicus) marthae Hobbs

Procambarus (Ortmannicus) marthae Hobbs, 1975:6, fig. 2.

TYPES.—Holotype, allotype, and morphotype, USNM 145994, 145995, 145996 (male I, female, male II); paratypes, USNM.

TYPE LOCALITY.—Small, very sluggish stream, 2.3 miles (3.7 km) west of the Alabama River on U.S. Highway 84, Monroe County, Alabama.

RANGE.—Alabama River basin in Dallas, Hale, Monroe, and Perry counties, Alabama.

HABITAT.—Lentic and sluggish lotic situations.