Fallicambarus (Creaserinus) danielae Hobbs 1975

Fallicambarus (Creaserinus) danielae Hobbs

Cambarus lobdelli Lyle, 1938:76 [nomen nudum].

Fallicambarus (Creaserinus) danielae Hobbs, 1975:28, fig. 8.

TYPES.—Holotype, allotype, USNM 145997, 145998 (male I, female); paratypes, USNM.

TYPE LOCALITY.—Burrows in a roadside ditch 9.0 miles (14.4 km) east of Ocean Springs, Jackson County, Mississippi, on U.S. Highway 90.

RANGE.—Known only from Jackson County, Mississippi, and Mobile County, Alabama.

HABITAT.—Burrows.

Fallicambarus (Creaserinus) danielae

DIAGNOSIS.—Antennal scale reduced, very narrow; ventral surface of propodus of chela with longitudinal row of stiff setae near lateral margin; merus of cheliped lacking ventrolateral row of setae and tubercles of two ventral rows very weak; mesia ramus of uropod with distolateral spine; first pleopod of first form male almost straight, and mesial process extending much farther caudad than central projection; abdomen of male distinctly narrower than cephalothorax; boss on coxa of fourth pereiopod of male directed mesially; annulus ventralis not broadly excavate and not obscuring sclerite immediately caudal to annulus.

HOLOTYPIC MALE, FORM I.—Eyes very small. Cephalothorax subovate, compressed (Figure 8a,l). Abdomen distinctly narrower than thorax (7.2 and 9.9 mm); greatest width of carapace subequal to depth at caudodorsal margin of cervical groove (9.9 and 9.8 mm). Areola obliterated along most of its length; length 41.8 percent of entire length of carapace (46.6 percent of postorbital carapace length). Rostrum with convergent, narrow, and only slightly elevated margins, gently contracted to form short indistinctly delimited acumen; slightly upturned tip almost reaching midlength of penultimate podomere of antennular peduncle; dorsal surface of rostrum mostly subplane, only slightly excavated with comparatively few punctations except submarginally. Subrostral ridges weak and evident in dorsal aspect only in caudalmost part of orbital region. Postorbital ridges rather weak with flanking row of prominent punctations laterally and band of similar ones mesially. Suborbital angle and branchiostegal and cervical spines lacking. Carapace punctate dorsally, very sparsely so cephaIodorsally, and weakly granulate laterally; hepatic region with very few small tubercles; accessory grooves and depressions as illustrated (Figure 8a).

Abdomen subequal in length to carapace (22.0 and 21.1 mm); pleura (Figure 8m) short and broadly rounded; cephalic lobe of pleuron of second abdominal segment slightly overlapping reduced pleuron of first. Telson clearly divided into cephalic and caudal sections (Figure 8h); dextral margin with fixed spine distal to midlength, corresponding position on sinistral margin bearing additional small movable spine mesial to fixed one; entire dorsal surface of telson studded with fine, short setae. Proximal podomere of uropod (Figure 8h) without spines. Both rami rounded distally, and each with fixed spine on lateral margin; mesial ramus with premarginal distomedian spine at extremity of median keel; lateral ramus also with moderately prominent submedian keel.

Cephalomedian lobe of epistome (Figure 8d) subtriangular with margins elevated and flanked caudally by prominent row of setae; main body with median fovea and paired, rather deep, transverse grooves along cephalic margin of epistomal zygoma, lateral extremities with surface irregular but lacking tubercles. Ventral surface of proximal podomere of antennule without spine. Antennal peduncle lacking spines, flagellum reaching first abdominal segment. Antennal scale (Figure 8k) three times as long as broad, broadest slightly distal to midlength, evenly rounded mesially, and lateral margin arched and bearing setiferous punctations; distolateral spine heavy and reaching base of ultimate podomere of antennular peduncle. Ventral surface of ischium of third maxilliped (Figure 8j) with mesial portion bearing tufts of long stiff setae, submarginal lateral row of shorter plumose setae, and distal half with tufts of plumose setae between latter and mesial tufts.

Right chela (Figure 8q) only slightly more than twice as long as broad, strongly depressed; mesial margin of palm with row of 8 tubercles subtended dorsally by row of 6 smaller ones, and ventrally by 2, latter underlying distal tubercles of longest row (left chela without tubercles ventrally); dorsal surface of palm with scattered punctations, sparse proximally but with prominent ones at base of fixed finger; ventral surface with arched sublateral row of punctations bearing tufts of long stiff setae, few additional setae sparsely scattered over surface; distal ridge on ventral surface opposite base of dactyl with 2 tubercles and proximal extension of curved ridge on fixed finger with row of 8 prominent tubercles flanked proximolaterally by 1 (Figure 8p) (left chela with 1 tubercle on ridge, and 6 in row); part of prominent tuft of setae between fingers arising between and dorsal to tubercular row. Opposable margin of fixed finger with 3 large tubercles decreasing in size distally, and proximal 2 largely concealed among prominent setal mat borne on basal half of finger; row of minute denticles present between distal 2 tubercles and between distalmost and corneous tip of finger; dorsal surface of finger with prominent curved, submedian rib flanked by setiferous punctations, some setae long and stiff; lateral surface strongly costate, bearing punctations studded with stiff setae, costa extending onto distal portion of palm; ventral surface of finger with prominent ridge, its proximal portion bearing tubercles mentioned in description of palm. Opposable margin of dactyl with proximal excavation divided into thirds by 2 tubercles: proximal one much larger than more distal one and slightly larger than tubercle marking distal end of excavation; latter followed by 3 smaller tubercles and row of minute denticles reaching corneous tip of finger (corresponding margin of left chela with 5 small tubercles distal to that marking distal end of excavation); dorsal surface of dactyl with broader and longer submedian rib than that on fixed finger, rib flanked along most of its length by setiferous punctations and proximomesially by few tubercles; mesial surface of dactyl with cluster of tubercles along proximal third, followed distally by row of setiferous punctations; ventral surface with longitudinal ridge and scattered setiferous punctations.

Carpus of cheliped with prominent submedian furrow dorsally, remainder of dorsal surface with setiferous punctations; mesial surface with single prominent spikelike tubercle and cluster of smaller ones immediately proximal to it (only one visible in Figure 8q because of tilted carpus); ventral surface with prominent median tubercle on distal margin and much smaller one on articular knob; lateral surface with setiferous punctations. Merus with dorsodistal surface bearing several small tubercles, one slightly larger than others; ventral surface with mesial row of 12 small tubercles and lateral row of 4 yet smaller ones; mesial and lateral surfaces sparsely punctate. Basioischial podomere with only 1 well-defined tubercle; sufflamen well developed.

Chela of second pereiopod with rows of conspicuous setae on extensor and flexor margins as well as on proximomesial surface of palm; similar setae present in clusters on dorsomesial and mesial surfaces of carpus and along ventral margin of merus.

Ischium of third pereiopod with simple strong hook overreaching basioischial articulation (Figure 7g), hook not opposed by tubercle on basis. Coxa of fourth pereiopod with prominent caudomesial boss flattened caudally and bearing narrow, curved ridge mesially. Coxa of fifth pereiopod with boss represented by low elevation at ventral caudomesial angle; ventral membrane setiferous.

First pleopod (Figure 8b,f,o) reaching coxa of third pereiopod and situated comparatively deep within sternum, obscured by setae extending caudally and mesially from ventral margin of sternum; proximomesial spur lacking; distal half of shaft relatively straight, not inclined caudally; terminal elements consisting of: corneous, broad, rather short, bladelike, subterminally notched central projection; and mesial process with corneous subspatulate distal portion contiguous with ventrodistal extremity of central projection (although not obscuring any part of it in lateral aspect) and extending caudally much beyond tip of latter; cephalic process absent.

ALLOTYPIC FEMALE.—Differing from holotype in following respects: mesial lobe of proximal podomere of uropod with distinct spine; cephalic lobe of epistome with cephalolateral margins slightly more arched, and main body lacking fovea; length of chela slightly less than twice as long as broad; mesial margin of palm with row of 7 (right chela) or 8 (left) tubercles; ventral surface of palm with proximal extension of curved ridge on fixed finger bearing row of 5 (right) or 7 (left) tubercles, that proximolateral to row present or absent; opposable margin of dactyl with distal tubercle in proximal excavation much smaller than that in holotype, and with 4 or 5 small tubercles distal to large one marking distal extremity of excavation; merus with ventromesial row of 11 tubercles and ventrolateral row of 4 or 5. (See “Measurements.”)

Annulus ventralis (Figure 8i) subrectangular, subsymmetrical, broader than long, and firmly fused to sternum cephalically; central region depressed and bearing dextrally directed tongue; sinus originating on median line slightly cephalic to midlength, extending caudodextrally, making hairpin turn before turning caudally, and, reaching median line, almost following it caudally and ending on steep caudal wall; fossa disappearing below hairpin curve. Sclerite immediately caudal to annulus subtriangular, shorter than broad, and little more than one-third as broad as annulus; surface elevated ventrally and bearing prominent punctations caudal to midlength. First pleopod long, reaching short distance beyond cephalic margin of annulus when abdomen flexed.

SECOND FORM MALE.—The male, form II, is known only from the cast exoskeleton of the holotype, and, as might be anticipated, differs in no important aspect (other than secondary sexual characteristics) from the instar described above. The hook on the ischiopodite of the third pereiopod is smaller and less acute, but the bosses on the coxae of the fourth and fifth pereiopods are almost as well developed as they are in the first form male. The first pleopods (Figure 8c,e) lack corneous elements, the subapical notch of the central projection is indistinct, and the distal part of the mesial process is less clearly spatulate than that in the first form individuals. The prolongation of the mesial process caudally beyond the tip of the central projection is as conspicuous in this test as in either of the first form males available.

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