Procambarus xochitlanae Hobbs 1975

Procambarus (Villalobosus) xochitlanae Hobbs (1975b:16); reported by Hobbs (1975b:19)

San Luis Potosf

Macrobrachium carcinus; reported by Breder (1942:11) as Macrobrachium jamaicensis (Herbst).

Procambarus (Ortmannicus) acutus cuevachicae (Hobbs, 1941a:1) [Cambaridae]; reported by Bridges (1940:84) as crayfish.

Procambarus (O.) toltecae; reported by Hobbs (1971a:37).

Procambarus (Ortmannicus) villalobosi Hobbs (1969a:41) [Cambaridae]; reported by Hobbs (1969a:41).

Pseudothelphusa (Tehuana) cordobensis Rodríguez and Smalley (1972:77) [Pseudothelphusidae]; reported by Rodríguez and Smalley (1972:77).

Procambarus (Villalobosus) xochitlanae Hobbs

Procambarus (Villalobosus) xochitlanae Hobbs, 1975:16, fig. 5.

TYPES.—Holotype, allotype, morphotype, USNM 145610, 145611, 145612 (male I, female, male II); paratypes USNM, IBM, TTM.

TYPE LOCALITY.—Cueva de Los Camarones (Río Tecolutla Basin), 3 kilometers (1.9 mi) northwest of Xochitlán, Puebla, Mexico.

RANGE.—Known only from the type locality.

HABITAT.—Subterranean stream.

Procambarus (Villalobosus) xochitlanae

DIAGNOSIS.—Pigmented, eyes well developed. Rostrum without marginal spines or tubercles, median carina absent. Carapace without cervical spines. Areola 4.3 to 7.0 times longer than broad and constituting 33.3 to 34.7 percent of total length of carapace (39.3 to 40.9 percent of postorbital carapace length). Suborbital angle obtuse. Postorbital ridge without spines or tubercles. Hepatic area without spines. Antennal scale approximately 1.8 times longer than wide, broadest distal to midlength. Ischium ot fourth pereiopod of first form male with prominent hook not overreaching basioischial articulation, that of third pereiopod with hook reduced to small tubercle; coxa of fourth pereiopod with laterally directed, rounded, distally acute boss. First pleopod of first form male reaching caudal margin of coxa of second pereiopod, asymmetrical, devoid of subapical setae; distal extremity bearing heavy, corneous, caudally-bowed mesial process far overreaching other terminal elements; cephalic process consisting of small, noncorneous, compressed, rounded prominence on cephalomesial distal side of small, corneous, beaklike central projection, latter directed subcaudally; caudal process corneous, subspiniform, situated lateral to central projection and directed caudodistally. Annulus ventralis convex cephalically, concave caudally with submedian S-shaped sinus situated in cephalically convex elevation. Sternum cephalic to annulus unadorned; postannular plate prominent, elevated cephaloventrally in broad heavy prominence. First pleopod present in female.

HOLOTYPIC MALE, FORM I.—Cephalothorax (Figure 4 a,i) subovate, compressed. Abdomen narrower than thorax (9.3 and 9.7 mm). Greatest width of carapace subequal to height at caudodorsal margin of cervical groove. Areola 5.8 times longer than wide with 4 punctations across narrowest part. Cephalic section of carapace approximately twice as long as areola; length of latter 33.5 percent of entire length of carapace (39.3 percent of postorbital carapace length). Rostrum with somewhat thickened, convergent margins devoid of marginal spines or tubercles, and reaching base of ultimate podomere of antennular peduncle; dorsal surface excavate with deep, some what coalescing punctations and usual submarginal row of setiferous punctations. Subrostral ridges moderately strong and evident in dorsal aspect along proximal fourth of rostrum. Postorbital ridges rather heavy, swollen caudally, grooved dorsolaterally, and terminating cephalically with out spines or tubercles. Suborbital angle obtuse. Cervical spine lacking. Branchiostegal spine small. Surface of carapace punctate dorsally and dorsolaterally, ventral portion of branchiostegite mostly granulate, and hepatic region mostly tuberculate.

Abdomen slightly longer than carapace (23.4 and 22.4 mm). Pleura of third through fifth abdominal segments truncate ventrally, rounded cephalo- and caudoventrally. Cephalic section of telson with 4 spines in each caudolateral corner. Cephalic lobe of epistome (Figure 5h) subcordiform with cephalolateral portion strongly elevated (ventrally); fovea not prominent. Ventral surface of proximal podomere of antennular peduncle with small distomesial spine. Antenna broken but reaching at least midlength of abdomen in paratypes. Antennal scale (Figure 5l) 1.8 times longer than wide and widest distal to midlength; lamellar portion slightly more than twice width of thickened lateral part.

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

Right chela (Figure 5m) subovate in cross section, not strongly depressed. Mesial margin of palm with row of 8 tubercles subtended ventrally by row of 6 and dorsally by row of 7; additional conspicuous tubercles scattered over remainder of dorsal surface of palm, and lateral margin subserrate. Both fingers bearing dorsomedian longitudinal ridge flanked proximally by tubercles giving way quickly to setiferous punctations. Opposable margin of fixed finger with row of 10 rounded, corneous tubercles along proximal four-fifths of finger, second from base largest, and additional large one at lower level between seventh and eighth tubercles of row; minute denticles present from ninth tubercle distally to base of corneous tip of finger. Opposable margin of dactyl with row of 9 tubercles followed distally by row of minute denticles; mesial margin of dactyl with 2 prominent tubercles on proximal third and setiferous punctations extending distally almost to tip of ringer. Palm and proximal part of both fingers tuberculate ventrally.

Carpus of right cheliped longer than broad, tuberculate dorsally and mesially, with 2 tubercles on mesial surface somewhat larger than others; dorsal surface also bearing broad, shallow, sinuous furrow; and ventral surface smooth except for usual 2 marginal tubercles.

Merus of right cheliped tuberculate dorsally, distolaterally, and distomesially; no tubercles acute, those on dorsal surface progressively larger distally; ventral surface with mesial row of 10 subacute, mostly corneous-tipped, and lateral row of 8 less acute ones. Ischium with row of 3 small tubercles ventromesially.

Hook on ischium of fourth pereiopod (Figure 5k) prominent, rather heavy, but not projecting proximally over basioischial articulation; that on ischium of third pereiopod vestigial, reduced to small tubercle situated slightly distal to midlength. Coxa of fourth pereiopod with prominent, transversely directed boss; latter rounded mesially and tapering distally. Coxa of fifth pereiopod with very small boss on caudomesial ventral area immediately lateral to phallic papilla.

Sternum between second, third, and fourth pereiopods moderately deep, with short fringe of setae on ventrolateral margins.

First pleopods (Figure 5c,f,g,j) as described in “Diagnosis.” Uropod with both lobes of basal podomere bearing acute spines; distomedian spine on mesial ramus not reaching distal margin of ramus.

ALLOTYPIC FEMALE.—Differing from holotype in following respects: punctations on carapace more conspicuously setose; epistome with distinct cephalolateral angles; mesial row of tubercles on palm of chela subtended ventrally by row of 9 tubercles and dorsally by row of 8; opposable margin of fixed finger with row of 7 tubercles, third from base largest: opposable margin of dactyl with minute denticles extending distally from fifth tubercle from base; carpus of cheliped with only 1 tubercle larger than others; merus of cheliped with ventromesial row of 15 tubercles and lateral one of 9; ischium of cheliped with onlv 1 tubercle ventromesially.

Annulus ventralis (Figure 5b) moderately deeply embedded in sternum, convex cephalically, and concave caudally, bearing submedian sinuous sinus cutting caudal wall; sternum cephalic to annulus smooth, lacking caudal tubercles or projections; postannular plate as long in median line as annulus, its cephalomedian area strongly elevated and rounded. First pleopod extending almost to cephalic margin of annulus when abdomen flexed.

MORPHOTYPIC MALE, FORM II.—Differing from holotype in following respects: cephalic section of telson with only 3 spines in caudosinistral corner; epistome with subacute cephalolateral angles; mesial surface of palm of chela with row of 6 tubercles subtended ventrally by row of 8, and dorsally by irregularly placed tubercles, only 2 in row; opposable margin of fixed finger of chela with row of 8 tubercles (fourth from base largest) on proximal two-thirds; opposable margin of dactyl with row of 6 tubercles; ventral surface of carpus with several tubercles; merus with ventromesial row of 9 tubercles and additional ones mesial and lateral to row, 2 strong ones distomesially; hook on ischium of fourth pereiopod not so strong, no vestige of hook on ischium of third; boss on coxa of fourth pereiopod greatly reduced and that on fifth not prominent.

First pleopod (Figure 5d,e) strongly resembling that of holotype but lacking corneous elements; cephalic process poorly defined and not so strongly compressed; caudal process not nearly so acute, shorter, and broader; and central projection smaller, less conspicuous, and not evident in mesial aspect of appendage.

MEASUREMENTS (in mm).—

TYPE-LOCALITY.—Cueva de Los Camarones (Río Tecohitla Basin), 3 km northwest of Xochitlán, Pucbla, Mexico. Collected by James R. Reddell on 29 December 1973. His description of the cave (Reddell, 1974:186) is as follows:

This cave is located at the head of and about 15 m above the door of a short canyon across the river and slightly upstream from Grutas de Ateno. From below it appears to be a wide shelter but closer inspection reveals two passages leading out from the shelter. On the left is a small hole in breakdown which extends as a 35 m crawlway, ending in breakdown. The main passage, however, is a 7 m wide, 1.5–2.0 m high passage floored with a few inches of water. This pond is formed by the breakdown in the shelter and is fed by a small stream. The water seeps through the breakdown to emerge below the cave entrance as a seep. The wide ponded area is about 15 m long, at which point it opens into a 2–3 m high, dry passage with the stream meandering across the floor. After 15 m the passage becomes a 1 m high, 1.5 m wide crawl along a stream passage. This was explored for 30 m and continues beyond this point with the same dimensions. The cave apparently has no local name so it was named for the large population of crayfish inhabiting the ponded area.

DISPOSITION OF TYPES.—The holotypic male, allotype, and morphotypic male are deposited in the National Museum of Natural History (Smithsonian Institution) numbers 145610, 145611, 145612, respectively, as are the following paratypes: 4 , 5 juv., and 6 juv. Of the remaining paratypes, 1 II, and 1 are in the Instituto de Biología, Universidad Nacional Autónoma de México, and 1 II, and 1 in the Museum, Texas Tech University, Lubbock, Texas.

SIZE.—The largest specimen is a female having a carapace length of 25.9 mm (postorbital carapace length, 23 mm); the holotype, with corresponding lengths of 22.4 and 19.1 mm, is the only first form male available. No ovigerous females are known.

RANGE AND SPECIMENS EXAMINED.—The only specimens are those cited above from the type-locality.

VARIATIONS.—Areola with 4 or 5 punctations across narrowest part; cephalic section of telson with 3 or 4 spines in each caudolateral corner; epistome usually with excavate cephalolateral margins and lateral obtuse or subacute angle; mesial margin of palm of chela with 6 to 8 tubercles in mesialmost row, 6 to 8 in adjacent ventral row, and 2 to 7 in adjacent dorsal row; opposable margin of fixed finger of chela with row of 6 to 9 tubercles and that of dactyl with 6 to 10; mesial surface of carpus of cheliped with 2 or 3 tubercles somewhat larger than others, and ventral surface smooth or with few scattered low tubercles; merus of cheliped with ventromesial row of 9 to 14 tubercles and ventrolateral row of 4 to 11; ischium with 0 to 4 tubercles. See also “Diagnosis” and “Measurements.”

RELATIONSHIPS.—Procambarus (Villalobosus) xochitlanae is closely related to P. (V.) tcziutlanensis (Villalobos, 1947a:240) and P. (V.) tlapacoyanensis (Villalobos, 1947b:537), both of which occur in the adjacent watershed, Rio Nautla, to the south in Puebla and Veracruz, respectively. Among the many features shared in common by the three are a conspicuously prominent mesial process of the first pleopod in the male and a comparatively prominent cephaloventrally protruding and rounded postannular plate that fits into the concavity on the caudal wall of the annulus. This crayfish may be distinguished from both species mentioned by the terminal elements of the first pleopod of the male: the well-defined cephalic process is directed caudodistally and extends distinctly beyond the central projection distally; both the central projection and caudal process extend distinctly more caudally than distally; and the distally broadly rounded mesial process (neither tapering as in P. teziutlanensis nor flattened as in P. tlapacoyanensh) is strongly bowed (not sinuous) with the convexity on its caudal surface. Also the areola is broader in P. xochitlanae than in either of the other species.