Ancistrochelifer orientalis (Beier, 1967) Beier, 1967

Dashdamirov, Selvin, 2006, A new species of the false­scorpion family Cheliferidae from Thailand, with remarks on Ancistrochelifer and Metachelifer (Arachnida: Pseudoscorpiones), Zootaxa 1325, pp. 347-362 : 349-353

Ancistrochelifer orientalis (Beier, 1967) , comb. n.

Figs 2–10

Material. Male: SMNS 3689, Thailand, Chiang Mai Prov., N Doi Suthep [5], 18°48´N, 98°55´E, 1400 m, under bark, 31 December 1988, leg. J. Trautner & K. Geigenmüller.

Other material examined. Female, holotype of Hysterochelifer orientalis : BBM 7422, NW Thailand, Chiang Mai Prov., N Doi Suthep [5], 1–5 April 1958, leg. T. C. Maa.

Diagnosis. Differs from both hitherto known congeners by the presence of a large tooth on the dorsal side of the lateral tarsal claw of male leg I, by the smaller overall sizes of both sexes, with the palps and legs more robust.

Description. Male from Doi Suthep (SMNS 3689). Colour of carapace, palps and tergites dark brown, remaining parts (legs, sternites and pleural membranes) light yellowish brown. Carapace slightly (1.05 times) broader than long, with a pair of welldeveloped eyes, surface evenly and strongly granular. Slightly elongate, well­developed, paramedian impressions behind eyes. Dorsal setae of carapace, palps and tergites short and denticuloclavate, borne on larger but relatively inconspicuous tubercles. Chaetotaxy of carapace: anterior margin with four setae, posterior margin with eight setae (total ca 64 setae); median and posterior furrows prominent, regularly granular. Tergal chaetotaxy: 12:9:10:11:12:14:14:13:13:11:10(8+2 long tactile setae):2(short, but incrassate and denticulate terminally). Coxal chaetotaxy: P 16–18, manducatory process with a total of four setae (one long apical, two rather short subapical setae and one suboral seta lying at base of medial margin); I 8–9; II 8–9; III 13; IV 30–34. Coxal sac taking up almost 2/3 coxal length. Atrium well­visible.

Microlyrifissures of abdomen relatively few and inconspicuous, except on eleventh tergite and sternite.

Chaetotaxy of sternites: x:34(some setae bifurcated):22(14+8 on internal parts):9:14:15:15:14:15:11(9+2 long tactile setae):8(6+2 long tactile setae):2 short and acuminate setae.

Because only one specimen was available for study, the structure of the genitalia could not be examined in due detail. All that was possible to see were the thicker, anteriorly fused lateral rods, the absence of a sagittal rod (statumen convolutum), as well as the wellvisible eversible sacs (ramshorn organs) and accessory glands.

Chelicera in basal part with moderate mesh­like reticulation dorsally; five setae in basal part, setae SB and B denticulate; movable finger with a seta distad of midway of finger; serrula exterior with 20 lamellae; lamina exterior present; flagellum with three blades, anterior one weakly denticulate distally. Galea with five short branches. Fixed finger with five small intermediate teeth.

Palp with trichobothriotaxy as illustrated ( Figs 6, 8 ). Palp relatively slender, fingers rather thick in dorsal view, all segments strongly granular, except for chelal hand and fingers, which are smooth; dorsal setae short and prominently denticuloclavate; proportions: trochanter 1.82 times as long as broad; femur 4.16 times as long as broad; patella 4.30 times as long as broad; chela with pedicel 3.88 times as long as broad, its chaetotaxy pattern, venom apparatus and dentition as illustrated ( Fig. 8 ); chela without pedicel 3.57 times as long as broad. Hand with pedicel 2.22 times, without pedicel 1.92 times, as long as broad. Hand with pedicel 1.24 times, without pedicel 1.07 times, as long as movable finger. Fixed finger of chela with 46 marginal teeth and with 14 pores (sensory spots) situated on medial side, linearly between IB/IST and IT; movable finger with 50 marginal teeth. Lamina defensor of fixed finger with a subapical notch on anterior side.

Venom apparatus present in both chelal fingers, venom duct in movable finger elongate, nodus ramosus close to level of trichobothrium IT.

Leg IV of typical facies, tibia and tarsus without tactile setae, with numerous denticulate setae and well­visible scale­like sculpture; proportions: femur+patella 3.07 times as long as deep; tibia 3.94 times as long as deep; tarsus 4.87 times as long as deep, with simple claws. Subterminal seta of tarsus simple, arolium shorter than claws.

Leg I: surface weakly scale­like sculptured; tibia 2.25 times as long as deep; tarsus 3.18 times as long as deep. Subterminal seta simple. Claws modified and asymmetrical ( Figs 11 & 13 ): lateral claw longer than mesal one, broadened, subscapuliform and microdenticulate terminally, with a long curved apodeme; mesal claw with a large tooth dorsally.

Measurements (length/breadth, in mm).

Carapace 0.93/0.98. Palp: trochanter 0.46/0.26; femur 0.93/0.22; patella 1.09/0.25; chela with pedicel 1.50/0.39; length of chela without pedicel 1.38; length of hand with pedicel 0.86, without pedicel 0.74; length of movable finger 0.69. Leg IV: femur+patella 0.74/0.242; tibia 0.55/0.14; tarsus 0.47/0.10. Leg I: tibia 0.32/0.14; tarsus 0.3/0.12.

Brief redescription. Female, holotype (BBM 7422). Carapace slightly (1.09 times) broader than long, with a pair of well­developed eyes, surface evenly and strongly granular, anterior margin with four setae, posterior margin with ten setae; median and posterior furrows prominent, regularly granular. Well­developed paramedian impressions behind eyes like in male. Tergal chaetotaxy: 12:10:10:12:12:13:14:13:11:12:10(8+2 long tactile setae?):2(short, but incrassate and denticulate terminally).

Abdomen being partly deformed, especially so ventrally, sternal setation patterns impossible to trace. Genitalia, though studied through deformed sterna, clearly showing a cribriform plate consisting of a single, central, unpaired plate ( Fig. 4 ).

Proportions of palp: trochanter 1.61 times as long as broad; femur 3.71 times as long as broad; patella 3.59 times as long as broad; chela with pedicel 3.77 times as long as broad, its chaetotaxy pattern, venom apparatus and dentition as illustrated ( Figs 9, 10 ); chela without pedicel 3.57 times as long as broad. Hand with pedicel 2.06 times, without pedicel 1.81 times, as long as broad. Hand with pedicel 1.04 times as long as movable finger. Movable finger 1.09 times as long as hand without pedicel. Fixed finger of chela with about 50 marginal teeth and with 13 pores (sensory spots) situated on mesal side, seven pores on lateral side; six short chemosensory(?) hairs on dorsal side. Movable finger with about 54 marginal teeth and with four pores on lateral side; diploid sensillum closer to SB. Lamina defensor of fixed finger with a subapical notch on anterior side.

Subterminal seta of tarsus simple.

Measurements (length/breadth, in mm).

Carapace 0.87/0.95. Palp: trochanter 0.45/0.28; femur 0.89/0.24; patella 0.90/0.25; chela with pedicel 1.52/0.40; length of chela without pedicel 1.44; length of hand with pedicel 0.83, without pedicel 0.73; length of movable finger 0.80.

Remarks. This genus is well­defined primarily by the peculiar shape of the lateral claw of male leg I ( Fig. 11 ). A. orientalis is very close to A. agniae , from which it differs primarily by the presence of a large tooth on the dorsal side of the mesal tarsal claw of male leg I. In addition, A. orientalis is smaller in size, and its palps and legs are more robust.

It is noteworthy that the internal structure of the male genitalia of A. agniae as illustrated by Beier (1951, p. 106, fig. 37) seems to have been misinterpreted, because the lateral rods are shown as consisting of four elements located close to one another. In any event, there must have been only two lateral rods present there.

Regrettably, the too scant material has not allowed me to make a preparation to thoroughly examine such an important character as the shape of the lateral rods of the male genitalia. All that was visible is that the rods are fused terminally, at this point being strongly curved posteriad and creating a deep notch, without a sagittal rod. Besides this, the atrium on coxae IV is present, while the female shows an unpaired cribriform plate. By these characters, it seems impossible to include Ancistrochelifer into the tribe Cheliferini as defined by Hoff (1956), this genus rather representing the tribe Dactylocheliferini.

Finally, Schawaller’s (1991) report of A. agniae from eastern Nepal [6–8] is remarkable, apparently representing a remote, Himalayan outpost lying very far away from Cambodia [1] and South Vietnam [2]. Considering the beautiful illustrations (SEM micrographs) he provided for the Nepalese samples, there can be little doubt concerning conspecificity. This is further reinforced by all of the records of this species being restricted to lowland to mid­montane localities. Since A. tuberculatus is likewise known only from two mid­montane habitats in Laos [3, 4], while A. schawalleri subcortically from another mid­montane place in North Thailand [5], the distribution pattern of Ancistrochelifer can be considered as typically Oriental, southeast Asian.

Last but not least, Beier (1951) erred in the descriptions of both A. agniae and A. tuberculatus when stating that their mesal claws of the male were modified. In fact, it is the lateral claw that is modified.

Figures

FIGURES 2 – 10. Ancistrochelifer orientalis, male (2 – 3, 5 – 8) and female holotype (4, 9 – 10): 2 apex of right maxilla, showing chaetotaxy and suboral seta at medial margin of maxilla; 3 galea, dorsolateral view; 4 cribriform plate; 5 right chelicera, dorsal view, showing basal and subbasal setae; 6 left palp, dorsal view; 7 carapace, dorsal view; 8 mesal view of right chelal fingers; 9 lateral view of right chelal fingers, showing diploid sensillum; 10 tip of fixed finger of left chela, showing lamina defensor (ld). Scale: 0.5 (6 – 7), 0.2 (2, 5, 8 – 9), and 0.05 mm (3 – 4, 10).

FIGURES 11 – 14. Ancistrochelifer orientalis, male: 11 claws of tarsus I, mesal view; 12 genital area and coxa IV, ventral view (showing at—atrium, cs—coxal sac, lr—lateral rods); 13 tarsus and tibia of leg I, mesal view; 14 right tarsus IV, lateral view. Scale: 0.2 (12 – 14) and 0.1 mm (11).