Sarax mardua, Rahmadi, Cahyo, Harvey, Mark S. & Kojima, Jun-Ichi, 2010

Rahmadi, Cahyo, Harvey, Mark S. & Kojima, Jun-Ichi, 2010, Whip spiders of the genus Sarax Simon 1892 (Amblypygi: Charinidae) from Borneo Island, Zootaxa 2612, pp. 1-21 : 13-18

Sarax mardua sp. nov.

( Fig. 26–32 , 39–40 )

Material examined: Male holotype ( MZB.Ambl.151), INDONESIA: East Kalimantan: Kutai Timur Regency, Sangkulirang District, Pengadan Village, Gua Mardua , near Pengadan, GPS coordinates 1°13'55.13"N, 117°44'23.53"E (approximate), 19 August 2004, L. Deharveng & A. Bedos col., (KAL-119). Paratypes: 1 female and 2 juveniles (MNHN-Am.12), same locality data as holotype.

Diagnosis: Sarax mardua has a large body-size (adult body length 8.5 – 10.1 mm), distinct sexual dimorphism, with the pedipalp shorter in the female than the male, and color in alcohol pale yellow. The median eye tubercle is low and small, and is completely divided into two parts each with an eye, legs elongate, trichobothrium bt close to proximal margin of fourth basitibial segment, and trichobothrium bc about midway between bf and sbf.

Description: Male: Color in alcohol: Carapace yellowish pale, centrally with brown marks, flange yellow; pedipalp yellowish-brown except for tarsus brown and spine yellow; legs yellowish-brown, but patella dark brown; abdomen pale yellow.

Carapace ( Fig. 26 ): Width about 1.4 – 1.7 times its length; surface finely granulate, without setiferous tubercles; median sulcus deep in posterior one-third of carapace; 4 pairs of lateral sulci present; flange wide and bent upward; anterior margin rounded, with 5 frontal setae, anterior process visible from above. Median eye tubercle low and small, clearly divided into 2 parts each including eye, without apical setae; median eyes facing antero-laterally; lateral eyes close to lateral margin of carapace, small, with yellowish tapetum.

Chelicera ( Fig. 30 ): Dorsal surface smooth, with 2 fine frontal setae and several fine setae. Basal segment with 4 teeth: lower-most tooth largest, upper-most tooth bicuspid, with upper cusp larger than lower cusp; inner surface with several setae arranged in vertical row; outer surface with small tooth opposite bicuspid tooth, ventrally with several setae near proximal margin. Movable article with 5 small teeth almost equal in size.

Sternum ( Fig. 27 ): First sternite (= tritosternum) elongate, with paired apical and several other setae. Second and third sternites rounded and slightly doomed, with 4 and 1 seta, respectively, in addition to paired apical setae. Fourth sternite (= metasternum) with 4 setae.

Pedipalp ( Fig. 28 ): Strong and slender. Trochanter: antero-dorsal margin with 4 setiferous tubercles, and median spine; antero-ventral margin with ventro-anterior apophysis present on distal margin equipped with several setiferous tubercles. Femur: antero-dorsal margin with 4 major spines, 1 minor spine, several setiferous tubercles and small tubercles, length of spines: F1>F2>F3>F4; antero-ventral margin with 4 major spines (length FI>FII>FIII>FIV), 1 minor spine, several setiferous tubercle and small tubercles; 1 spine present dorsally of FI and as long as half of FI. Patella: antero-dorsal margin with 4 major spines (length P1>P2>P3>P4>), distributed in distal half length of patella, 1 minor spine, several setiferous tubercles and small tubercles, 1 minor spine as long as 1/3 of P1 length between P1 and distal margin of patella and, 1 spine between P4 and proximal margin; antero-ventral margin with 3 major spines (length PI>PII>PIII), several setiferous tubercles and small tubercles. Tibia: antero-dorsal margin with outer surface smooth and with 2 major spines, proximal spine about half as long as distal spine; antero-ventral margin with 1 major spine close to distal margin of tibia. Tarsus completely divided (claw clearly demarcated by articulation), with 2 spines on antero-dorsal margin: proximal spine short about 1/3 as long as distal spine, the spines separated each other by about two times basal diameter of proximal spine; cleaning organ ventrally with about 30 modified hairs; apotele present.

Legs ( Fig. 29 ): Femora of legs I – IV with small tubercles bearing setae. Tibia and tarsus of leg I with 23 and 41 segments, respectively; tibiae of legs II and III 2 -segmented; basitibia of leg IV 4 -segmented, fourth segment with 1 trichobothrium (value in parentheses: ratio of the distance from the trichobothrium to the proximal margin of the segment against the length of the segment), bt (0.40); distitibiae of legs II – IV each with 18 trichobothria bf (0.06), sbf (0.33), bc (0.20), bt close to proximal margin of basitibial fourth segment, bc about midway between sbf and bf ( Fig. 29 ). Tarsi of legs II – IV 4 -segmented; first segment greater than length of subsequent three segments combined; second segment with light-yellow transverse line; fourth segment without oblique slit; pulvilli present.

Genitalia: Covered ventrally by genital operculum, proximal margin slightly concave; lateral margin yellowish-brown and median part white, medial lobes larger than lateral lobes separated with brown marks on basal lateral lobes ( Fig. 40 ). In dorsal view, anterior margin of gonopods rounded with brown bands extending to mid-length ( Fig. 39 ).

Female: Distinct sexual dimorphism. Pedipalps short and stout ( Fig. 31 ), shorter than male. Pedipalpal femur on antero-dorsal margin with 3 major spines (length F2>F1>F3), antero-ventral margin with 3 spines (length FI>FII>FIII), between FI and proximal margin of femora with 1 spine about half of FI length. Pedipalpal patella on antero-dorsal margin with 4 major spines (length P1>P2>P3>P4), the spines located for most of patella length, the most distal spines between P1 and distal margin about half of P1 length; anteroventral margin with 3 major spines (length PI>PII>PIII). Tibia: antero-dorsal margin with 2 spines, proximal spines less than half distal spine. Pedipalp tarsus with two long spines, the distal spine longer than proximal one. Genitalia: with paired gonopods, soft and small, tube-like ( Fig. 32 ).

Measurements (in mm): male (n=1) [female (n=1)]; values for segments of the appendages are their lengths. Body length (excluding chelicera) 10.06 [8.47]. Carapace: median length 3.82 [3.35]; width 5.59 [4.47]; median eyes to anterior margin of carapace 0.08 [0.08]; distance between lateral eyes 2.71 [2.19]; lateral eye to anterior margin of carapace 0.54 [0.47]; lateral eye to lateral margin of carapace 0.16 [0.21]. Pedipalps: trochanter 1.43 [1.01]; femur 4.27 [3.31]; patella 5.18 [3.35]; tibia 1.87 [1.09]; tarsus 2.00 [1.49].

Leg I: femur 15.39 [11.39]; patella 0.79[0.70]. Leg II: femur 8.78 [6.79], patella 1.38 [0.86]; basitibia 9.45[5.63]; distitibia 5.08 [3.61]; metatarsus + tarsus 3.61 [3.07]. Leg III: femur 10.07 [7.37]; patella 1.41 [0.84]; basitibia 9.29 [7.10]; distitibia 4.81 [3.98]; metatarsus+ tarsus 3.56 [2.93]. Leg IV: femur 8.99 [6.87]; patella 1.07 [0.78]; basitibia 9.65 [7.74]; distitibia 4.38 [3.52]; metatarsus + tarsus 3.64 [3.02].

Etymology: The species name is derived from the name of the cave “Gua Mardua ” where the type material was collected (Gua means “cave”).

Distribution: Sarax mardua has only been found in the Sangkulirang Karst, East Kalimantan ( Indonesia) ( Figs. 41, 42 ).

Natural history: The species is known only from Gua Mardua where it occurs with a mite harvestman, Stylocellus sp. ( Opiliones , Stylocellidae ).

Remarks: Sarax mardua can be distinguished from S. sangkulirangensis by the presence of distinct sexual dimorphism, and the reduced median eye tubercle which is completely divided into two parts ( Fig. 26 ). The arrangement of the trichobothria differs from S. sangkulirangensis where trichobothrium bc is slightly closer to sbf than to bf ( Fig. 29 ); in S. sangkulirangensis , bc is slightly closer to bf than to sbf ( Fig. 25 )

Figures

FIGURES 26 – 32. Sarax mardua sp. nov., male holotype unless stated otherwise: 26. Frontal area of carapace; 27. Sternal area of opisthosoma, ventral view; 28. Antero-dorsal view of left pedipalp; 29. Fourth basitibial segment and distibiae of right leg IV; 30. Antero-dorsal view of left pedipalp, paratype female (MNHN-Am. 12); 31. External view of left chelicerae; 32. Female gonopods, dorsal view, (MNHN-Am. 12).

FIGURES 33 – 40. Male genitalia of Sarax species from Borneo: 33. S. cavernicola, dorsal view; 34. same, ventral view; 35. S. yayukae from West and Central Kalimantan, dorsal view; 36. same, ventral view; 37. S. sangkulirangensis new species, dorsal view; 38. ventral view; 39. S. mardua from Gua Mardua, East Kalimantan, dorsal view, 40. Ventral view. Scale bars: 0.5 mm.

FIGURES 41 – 42. Map showing the distribution of Sarax species: 41. The distribution in Southeast Asia, except for Sarax species from India and New Guinea. 42. A detailed map showing the distribution in the Sangkulirang Karst, East Kalimantan.

FIGURES 21 – 25. Sarax sangkulirangensis sp. nov., female holotype unless stated otherwise: 21. Frontal area of carapace of male paratype (MZB. Ambl. 150); 22. External view of left chelicerae; 23. Sternal area of opisthosoma, ventral view; 24. Antero-dorsal view of left pedipalp; 25. Fourth basitibial segment and distibiae of right leg IV, male paratype (MZB. Ambl. 150).