Rangkayo hitam Dhiya’ulhaq & Benjamin, 2025

Dhiya'ulhaq, Naufal Urfi, Benjamin, Suresh P., Buchori, Damayanti, Hidayat, Purnama, Scheu, Stefan & Drescher, Jochen, 2025, Expanding the taxonomy of crab spiders (Araneae, Thomisidae) in Sumatra: a new genus, five new species, and regional records, ZooKeys 1241, pp. 205-246 : 205-246

Rangkayo hitam Dhiya’ulhaq & Benjamin sp. nov.

Figs 23 , 24 , 25

Type material.

Holotype. Indonesia – Jambi Province • 1 ♂; Batang Hari, Hutan Harapan Conservation Area ; 02°09'52.9"S, 103°22'04.0"E; elev. 51 m; 2 Aug. 2013; J. Drescher leg.; canopy fogging in rainforest; GOET 2013_HFr 1.2_AraThom 091 N_001 (to be transferred to MZB) . Paratype. Indonesia – Jambi Province • 1 ♀; Batang Hari, Bajubang, Singkawang ; 01°47'07.9"S, 103°16'37.4"E; elev. 56 m; 18 Jun. 2013; J. Drescher leg.; canopy fogging in jungle rubber plantation; GOET 2013_HJ 4.1_AraThom 091 N_001 (to be transferred to MZB) . • 1 ♀; Batang Hari, Bajubang, Pompa Air ; 01°49'33.3"S, 103°17'38.1"E; elev. 51 m; 14 May 2013; J. Drescher leg.; canopy fogging in jungle rubber plantation; GOET 2013_HJ 2.1_AraThom 091 N_001 (to be transferred to MZB) .

Diagnosis.

Males of Rangkayo hitam Dhiya’ulhaq & Benjamin , sp. nov. can be distinguished from the only other species Rangkayo perkaso Dhiya’ulhaq & Benjamin , sp. nov. by the straighter cymbium (Fig. 23 G vs bent, Fig. 26 G ), lack of dorsal cymbial setae with widened base (vs present), smaller, round tegulum, not covering most of the embolic base (Figs 23 D , 25 A vs larger, oval-shaped, covering most of the embolic base, Figs 26 D , 28 A ), longer and straighter conductor (vs shorter and curved), and small tegular bump (vs large). Females can be distinguished by the more spaced CO (Figs 24 C, E , 25 C ), anterior region of atrium as wide as posterior region (vs anterior region narrower than posterior; Figs 27 C, E , 28 C ), CD with a narrower second loop, which does not encircle the first loop (Figs 24 D , 25 B vs fully encircling the first loop, Figs 27 B , 28 B ), posterior part of CD forming a longitudinal bow (vs transverse bow). Additionally, the abdominal red spots appear much larger and with a deeper colour than in R. perkaso (Figs 23 A , 24 A , 26 A , 27 A ), although this may reflect the condition of the specimens rather than a diagnostic trait.

Description.

Male (holotype 2013 _ HFr 1.2_AraThom 091 N_001; Figs 23 , 25 A ). Total length 3.42. Carapace length 1.61; width 1.41. Abdomen length 1.81; width 1.39. Diameter of eyes: AME 0.04; ALE 0.10; PLE 0.12; PME 0.08. Interdistances between eyes: AME – AME 0.07; AME – ALE 0.05; ALE – ALE 0.26; PME – PME 0.12; PME – PLE 0.10; ALE – PLE 0.12; AME – PME 0.22; PLE – PLE 0.51. Leg measurements: leg I 10.25 (2.78, 0.54, 3.19, 2.68, 1.06); leg II 10.62 (2.82, 0.48, 3.40, 2.82, 1.10); leg III 4.57 (1.40, 0.39, 1.33, 0.96, 0.49); leg IV 4.97 (1.51, 0.40, 1.45, 1.07, 0.54). Carapace pear-shaped, yellowish orange; eye region slightly darkened; AER recurved; PER slightly recurved. Legs uniformly yellow. Abdomen oval, yellow; dorsally with four pairs of large, red spots, interspersed by smaller white ones; laterally with a few small red spots in the posterior half. Palp (Figs 23 D – G , 25 A ): Cymbium 1.5 × length of tibia, straight, oval-shaped with a narrowed anterior extension. Tegulum round, not covering the long embolic base. Tegular bump small, prolaterally positioned. Conductor long and rather straight, tapering into a rounded tip. Embolus long, whip-like, curving around the prolateral side of the bulb, before distally curving to the other direction. Tibia ventrally with seven strong macrosetae.

Female (paratype 2013_HJ 4.1_AraThom 091 N_001; Figs 24 , 25 B, C ). Total length 3.76. Carapace length 1.60; width 1.48. Abdomen length 2.16; width 1.53. Diameter of eyes: AME 0.05; ALE 0.11; PLE 0.13; PME 0.09. Interdistances between eyes: AME – AME 0.09; AME – ALE 0.06; ALE – ALE 0.28; PME – PME 0.13; PME – PLE 0.13; ALE – PLE 0.13; AME – PME 0.21; PLE – PLE 0.55. Leg measurements: leg I 9.76 (2.66, 0.55, 3.14, 2.43, 0.98); leg II 10.08 (2.83, 0.56, 3.27, 2.52, 0.90); leg III -; leg IV -. Female habitus as in male, except the carapace is paler in colour. Epigynum (Figs 24 C – E , 25 B, C ): Atrium large, butterfly-shaped; anterior region as wide as posterior region. CO semicircular. CD very long and convoluted, anteriorly with two major loops; first loop after the CO appearing only as a half-circle, not encircled by the second loop. Next to the second loop is a straight tube running to the posterior. Posterior part of CD initiated by a longitudinal bow, followed by a series of folds and turns, ending in a rather inconspicuous, oval spermatheca.

Etymology.

See under etymology of genus. The specific epithet is a noun in apposition.

Distribution.

Indonesia (Sumatra: Jambi Province) Fig. 29 .

Figures

Figure 23. Rangkayo hitam Dhiya’ulhaq & Benjamin, sp. nov., male (holotype 2013 _ HFr 1.2 _ AraThom 091 N _ 001) A, B habitus A dorsal view B ventral view C eye region, frontal view D – G right palp (mirrored) D prolateral view E ventral view F retrolateral view G dorsal view. Scale bars: 1 mm (A, B); 0.2 mm (C – G).

Figure 24. Rangkayo hitam Dhiya’ulhaq & Benjamin, sp. nov., female (paratype 2013 _ HJ 4.1 _ AraThom 091 N _ 001) A, B habitus A dorsal view B ventral view C – E epigynum C ventral view D cleared, ventral view E cleared, dorsal view. Scale bars: 1 mm (A, B); 0.1 mm (C – E).

Figure 25. Rangkayo hitam Dhiya’ulhaq & Benjamin, sp. nov. A, B male (holotype 2013 _ HFr 1.2 _ AraThom 091 N _ 001), right palp (mirrored) A ventral view B, C female (paratype 2013 _ HJ 4.1 _ AraThom 091 N _ 001), epigynum B ventral view C dorsal view. Abbreviations: AT = atrium; C = conductor; CD = copulatory duct; CO = copulatory opening; E = embolus; EB = embolic base; FD = fertilisation duct; L 1 = first loop of copulatory ducts; L 2 = second loop of copulatory ducts; MA = median apophysis; S = spermatheca; TB = tegular bump. Scale bars: 0.2 mm.

Figure 26. Rangkayo perkaso Dhiya’ulhaq & Benjamin, sp. nov., male (holotype 2013 _ BJ 3.2 _ AraThom 056 N _ 001) A, B habitus A dorsal view B ventral view C eye region, frontal view D – G left palp D prolateral view E ventral view F retrolateral view G dorsalview. Scale bars: 1 mm (A, B); 0.2 mm (C – G).

Figure 27. Rangkayo perkaso Dhiya’ulhaq & Benjamin, sp. nov., female (paratype 2013 _ BF 4.2 _ AraThom 056 N _ 001) A, B habitus A dorsal view B ventral view C – E epigynum C ventral view D cleared, ventral view E cleared, dorsal view. Scale bars: 1 mm (A, B); 0.1 mm (C – F).

Figure 28. Rangkayo perkaso Dhiya’ulhaq & Benjamin, sp. nov. A, B male (holotype 2013 _ BJ 3.2 _ AraThom 056 N _ 001), left palp A ventral view B, C female (paratype 2013 _ BF 4.2 _ AraThom 056 N _ 001), epigynum B ventral view C dorsal view. Abbreviations: AT = atrium; C = conductor; CD = copulatory duct; CO = copulatory opening; E = embolus; FD = fertilisation duct; L 1 = first loop of copulatory ducts; L 2 = second loop of copulatory ducts; MA = median apophysis; S = spermatheca; TB = tegular bump. Scale bars: 0.2 mm.

Figure 29. Distribution of examined Thomisidae species from the Epidius clade (sensu Benjamin, 2011) prior to the present study, as well as the sampling location of the current study in Jambi Province, Sumatra, Indonesia (green flag). The new genus and the five new species described in the present study are all from the same study location, i. e., a replicated plot design across lowland rainforest, ‘ jungle rubber’ (rubber agroforestry), and smallholder monoculture plantations of rubber and oil palm in Jambi’s lowlands (Drescher et al. 2016).