Pengmarengo gepeng, Dhiya’Ulhaq , 2025

Pengmarengo gepeng Dhiya’ulhaq sp. nov.

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Figs 21–24 View Fig View Fig View Fig View Fig

Diagnosis

Pengmarengo gepeng Dhiya’ulhaq sp. nov. is most similar to Pengmarengo chelifer (Simon, 1900) and Pengmarengo yui ( Wang & Li, 2020) , but males can be distinguished from those of P. chelifer by the presence of an anterior-lateral process on tegulum ( Fig. 22B–E View Fig vs absent in P. chelifer [ Benjamin 2004: fig. 25a; Wanless 1978: fig. 9b, e]); from those of P. yui by a rhombic-shaped tegulum ( Fig. 22B, D View Fig vs oval in P. yui [ Wang & Li 2020: fig. 5b–d]). Females can be distinguished from those of P. chelifer by having two small coils on the posterior part of copulatory ducts ( Fig. 24B, D View Fig vs one coil in P. chelifer [ Benjamin 2004: fig. 26b–c]) and circular copulatory openings (vs oval in P. chelifer ); from those of P. yui by spermathecae having rounded bend ( Fig. 24B–C View Fig vs sharp bend in P. yui [ Wang & Li 2022: fig. 11b–c]) and oval copulatory openings (vs almost semi-circular in P. yui ). Additionally, both males and females of P. gepeng lack paired white spots on the opisthosoma vs present in P. chelifer ( Benjamin 2004: fig. 25d) and P. yui ( Wang & Li 2020: fig 6a–b; 2022: fig. 11d–f), as well as paired spots of white setae and distinct thoracic protuberance on carapace of P. yui .

Etymology

The specific epithet is taken from the Indonesian word ‘ gepeng ’, which can be translated to ‘sprawl’ or ‘flat’, referring to the flat body of this species. Noun in apposition.

Material examined

Holotype

INDONESIA – Jambi Province • ♂; Sarolangun, Bukit Duabelas National Park ; 1°59′42.6″ S, 102°45′08.0″ E; elev. 69 m; 8 Oct. 2013; J. Drescher leg.; canopy fogging in rainforest; GOET 2013_ BF1.1_AraSalt007N_001 (to be transferred to MZB). GoogleMaps

Paratype

INDONESIA – Jambi Province • 1 ♀; Sarolangun, Bukit Duabelas National Park ; 1°56′30.8″ S, 102°34′50.6″ E; elev. 91 m; 4 Oct. 2013; J. Drescher leg.; canopy fogging in rainforest; GOET 2013_ BF4.1_AraSalt007N_001 (to be transferred to MZB) GoogleMaps .

Description

Male ( Figs 21–22 View Fig View Fig )

MEASUREMENTS. Total length 2.79. Carapace length 1.29; width 0.74. Opisthosoma length 1.50; width 0.67. Diameter of eyes: AME 0.26; ALE 0.10; PLE 0.09. Interdistances between eyes: ALE–ALE 0.50; ALE– PLE 0.33; PLE–PLE 0.53. Leg measurements: leg I 2.95 (0.83, 0.33, 0.96, 0.59, 0.24); leg II 1.32 (0.39, 0.16, 0.33, 0.28, 0.16); leg III 1.24 (0.38, 0.12, 0.28, 0.27, 0.19); leg IV 1.62 (0.50, 0.19, 0.38, 0.33, 0.22).

HABITUS AND COLORATION. Carapace reddish-brown, elongated, flat surface pitted. Chelicerae red; dentition: two promarginal, three retromarginal. Opisthosoma slender oval, light brown; dorsally almost wholly covered in scutum. Leg I much thicker than other legs, especially tibia and tarsus; predominantly reddish-brown; tibia I with three pairs of ventral spines and flat tibial scales; metatarsus I with two pairs of ventral spines; rest of legs pale with dark lateral markings. Spinnerets basally light-brown, distally pale.

PALP ( Fig. 22 View Fig ). Tibia length-to-width ratio 0.95. RTA twice as long as tibia, tapering, distally slightly curved ventrally into rounded tip. Cymbium oval. Tegulum swollen, rhombic-shaped, divided by oblique cleft; short, rounded anterior-lateral process present. Embolus coiled approximately two times, coil width approximately two-thirds width of bulb; process of embolic disc membranous with blunt tip. Sperm duct thick, following retrolateral edge of tegulum.

Female ( Figs 23–24 View Fig View Fig )

MEASUREMENTS. Total length 2.87. Carapace length 1.27; width 0.69. Opisthosoma length 1.60; width 0.62. Diameter of eyes: AME 0.27; ALE 0.08; PLE 0.09. Interdistances between eyes: ALE–ALE 0.51; ALE–PLE 0.31; PLE–PLE 0.53. Leg measurements: leg I 2.14 (0.60, 0.22, 0.71, 0.41, 0.20); leg II 1.16 (0.31, 0.14, 0.29, 0.26, 0.16); leg III 1.09 (0.27, 0.12, 0.27, 0.24, 0.19); leg IV 1.61 (0.45, 0.15, 0.43, 0.39, 0.19).

HABITUS AND COLORATION. Female habitus as in male, except following: opisthosoma with dorsal scutum covering only anterior third; leg I slightly less robust, especially femur; lateral markings on legs II–IV less distinct.

EPIGYNUM ( Fig. 24 View Fig ). Epigynal plate rectangular, much longer than wide. Copulatory opening large, located anteriorly. Copulatory ducts long, initially rather straight before turning into 2 large U-turns, followed by two small coils. Spermatheca large, kidney-shaped. Fertilization ducts broken off during dissection.

Distribution

Sumatra: Jambi Province.

Natural history

All specimens were collected by canopy fogging in rainforests and are considered arboreal.