Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 (Araneae, Thomisidae) with descriptions of six new species from Southeast Asia

95 Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 (Araneae, Thomisidae) with descriptions of six new species from Southeast Asia Suresh P. Benjamin1, Naufal Urfi Dhiya’ulhaq2,3 , Christa Deeleman-Reinhold4,†, Damayanti Buchori5,6 , Purnama Hidayat5, Stefan Scheu2,7 , Jochen Drescher2,8 1 National Institute of Fundamental Studies, Hantana Road, Kandy 20000, Sri Lanka 2 Animal Ecology, J.F. Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Untere Karspüle 2, Göttingen 37073, Germany 3 Species Obscura, Jl. Duren 1 No.2, Depok, Jawa Barat 16434, Indonesia 4 Netherlands 5 Department of Plant Protection, Faculty of Agriculture, IPB University, Kampus IPB Dramaga Bogor, Jl. Raya Dramaga, West Java 16680, Indonesia 6 Centre for Transdisciplinary and Sustainability Sciences, IPB University, Kampus IPB Baranangsiang, Jl. Raya Pajajaran No.27, West Java 16127, Indonesia 7 Centre of Biodiversity and Sustainable Land Use, University of Göttingen, Büsgenweg 1, Göttingen 37077, Germany 8 Senckenberg Museum for Natural Sciences Görlitz, Am Museum 1, 02826 Görlitz, Germany Corresponding author: Jochen Drescher ([email protected]) Copyright: © Suresh P. Benjamin et al. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International – CC BY 4.0). Research Article Abstract The crab-spider genera Zametopina Simon, 1909 and Nyctimus Thorell, 1877 remain poorly studied, with significant gaps in their taxonomic understanding. Nyctimus has seen little study since its original description, and species assignments remain uncertain due to a lack of modern diagnostic data. By contrast, Zametopina, historically monotypic, was recently expanded with a second species (Z. wanliae Lin & Li, 2023) following a redescription of the type species, Z. calceata Simon, 1909. Our study presents a review of these genera, primarily based on specimens collected from tropical Asia by the late Christa L. Deeleman-Reinhold as well as from the EFForTS project in the lowlands of Sumatra, Indonesia. The review includes the description of the following six new species: Nyctimus falcatus Benjamin & Dhiya’ulhaq, sp. nov. (♂), Nyctimus kinabaluensis Benjamin & Dhiya’ulhaq, sp. nov. (♂♀), Nyctimus mutilloides Benjamin & Dhiya’ulhaq, sp. nov. (♂), Nyctimus quadripunctatus Dhiya’ulhaq & Benjamin, sp. nov. (♂♀), Nyctimus rendang Dhiya’ulhaq & Benjamin, sp. nov. (♂♀), and Nyctimus saksang Dhiya’ulhaq & Benjamin, sp. nov. (♂). Nyctimus bistriatus Thorell, 1877 is redescribed and new locality records are provided. Zametopina wanliae is recorded for the first time outside of Vietnam. Further, updated species descriptions of Nyctimus and Zametopina are provided, along with taxonomic clarifications of the genera. This study emphasises the fundamental importance of well-curated, historical collections and ongoing fieldwork in resolving the systematics of lesser-known arachnid lineages. Key words: Arachnida, biodiversity, RTA-clade, taxonomy Academic editor: Francesco Ballarin Received: 9 May 2025 Accepted: 18 August 2025 Published: 9 October 2025 ZooBank: https://zoobank. org/584332C1-8B4B-41B9-A17D327F47B5616A Citation: Benjamin SP, Dhiya’ulhaq NU, Deeleman-Reinhold C, Buchori D, Hidayat P, Scheu S, Drescher J (2025) Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 (Araneae, Thomisidae) with descriptions of six new species from Southeast Asia. ZooKeys 1255: 95–125. https://doi. org/10.3897/zookeys.1255.158380 ZooKeys 1255: 95–125 (2025) DOI: 10.3897/zookeys.1255.158380 † Deceased. 96 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Introduction Zametopina Simon, 1909, is a genus of crab spiders belonging to the family Thomisidae. Referred to as crab spiders, due to their elongated first two leg pairs and their habit of moving sideways, Thomisidae are among the most species-rich spider families with more than 2,100 species across 171 genera (World Spider Catalog 2025). Despite its inclusion in this diverse group, Zametopina remains relatively obscure and taxonomically unrevised. Initially, the genus comprised only a single species, Zametopina calceata Simon, 1909, which had been inadequately understood for decades due to a lack of illustrations in the original description. A significant update came with the work of Tang et al. (2010), who revisited and redescribed the type species. Through meticulous examination of the type specimen, they provided detailed illustrations and descriptions, thereby clarifying the diagnostic features of the genus and aiding in its taxonomic circumscription. This effort significantly enhanced the understanding of Zametopina and set the stage for future taxonomic studies. Recently, a second species, Zametopina wanliae Lin & Li, 2023, was described in Lin et al. (2023), further enriching the diversity of the genus. By contrast, the genus Nyctimus Thorell, 1877, has received limited taxonomic scrutiny since its initial description. Historically, Nyctimus included two species: the type species Nyctimus bistriatus Thorell, 1877, from Indonesia (Sumatra and Sulawesi), and Nyctimus trimeni (Simon, 1895) from South Africa. Originally described as Zametopias trimeni, the latter is likely misplaced, indicating a need for taxonomic revision. Additionally, Zametopias speculator Thorell, 1892, was transferred to Nyctimus and synonymised with N. bistriatus by Lehtinen (2016). However, this transfer was made without accompanying illustrations or a comprehensive re-examination of the type material, leaving the taxonomy of both species inadequately resolved. This paper aims to address some of these gaps by reviewing the poorly known species of both Zametopina and Nyctimus, primarily drawing on specimens collected from tropical Asia by the late Christa L. Deeleman-Reinhold, as well as from the EFForTS project in the lowlands of Jambi Province, Sumatra, Indonesia (Drescher et al. 2016). This review aims to clarify the taxonomy and provide updated descriptions, contributing to a more robust understanding of these genera and their roles in the biodiversity of the regions they inhabit. The study highlights the importance of revisiting historical collections and underscores the need for continued exploration and documentation of lesser-known spider taxa. Materials and methods Sample collection Specimens from the late Christa L. Deeleman-Reinhold’s personal collection, housed at her residence, were selected by Suresh P. Benjamin (SPB) and transferred to the Zoological Research Museum Alexander König (Bonn, Germany, ZFMK) for this study. These specimens, along with the rest of her collection, will ultimately be deposited at Naturalis Biodiversity Center, Leiden, Netherlands (RMNH). Spiders from Jambi Province were part of a collection of more than half a million canopy arthropods (Pollierer et al. 2023) sampled by canopy fogging 97 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 across rainforest, jungle rubber, and monocultures of rubber and oil palm in the lowlands of Jambi, Sumatra, Indonesia as part of the German-Indonesian EFForTS research project (Drescher et al. 2016). Overall, more than 10,000 spider individuals from at least 30 families and 400 species were captured (Ramos et al. 2022; Dhiya’ulhaq et al. 2024). The fogging method is detailed in Pollierer et al. (2023) and the EFForTS plot design and general study aims in Drescher et al. (2016). Identification and photography The general methodology follows Benjamin (2011) and Ileperuma Arachchi and Benjamin (2019). Specimens used for habitus illustrations were placed in 70% EtOH and photographed with a Zeiss AxioCam HRc camera mounted on a dissecting microscope (Zeiss Discovery V20) with top illumination and a magnification of up to 150×. Images were edited using the Zeiss ZEN Pro software package. Unless otherwise stated, depicted structures are of the left male palp. Alternatively, some specimens were examined under a ZEISS Stemi 2000 microscope. Female genitalia were excised from the specimen’s body and then cleared with 10% KOH for at least one hour to examine the internal copulatory organs. Imaging the specimens was done using a Keyence VHX-7000 digital microscope system or a Zeiss AxioCam HRc camera mounted on a dissecting microscope (Zeiss Discovery V20). The description of colouration is based on specimens in ethanol. Measurements of legs are given as total length (femur, patella, tibia, metatarsus, tarsus). Missing legs or leg segments are marked with “-”, and legs with missing segments do not have their total length recorded. Unmentioned legs did not have their length measured. All measurements are in millimeter. Abbreviations ALE anterior lateral eye AME anterior median eye CO copulatory opening FD fertilization duct PLE posterior lateral eye PME posterior median eye RTA retrolateral tibial apophysis of male palp VTA ventral tibial apophysis of male palp Repositories GOET Animal Ecology Group, J.-F. Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Germany (Jochen Drescher, Stefan Scheu) MCSN Museo Civico di Storia Naturale Giacomo Doria, Genoa, Italy (Maria Tavano) MCZ Museum of Comparative Zoology, Massachusetts (Gonzalo Giribet) MNHN Muséum National d’Histoire Naturelle, Paris (Christine Rollard) MZB Museum Zoologicum Bogoriense, Bogor, Indonesia (Cahyo Rahmadi) RMNH Naturalis Biodiversity Center, Leiden (Karen van Dorp) SMF Naturmuseum Senckenberg, Frankfurt a. M., Germany (Jana Grüger, Peter Jäger) ZMH Zoologisches Museum Hamburg, Hamburg, Germany (Nadine Dupérré, Danilo Harms) 98 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Results Family Thomisidae Sundevall, 1833 Nyctimus Thorell, 1877 Type species. Nyctimus bistriatus Thorell, 1877. Diagnosis. Small thomisids, 2–5 mm in body length. Prosoma cuboid, as long as wide, with granulated surface and bearing long macrosetae (Fig. 1). Body colouration dark with white/yellow markings, mostly in the form of spots and bars. Opisthosoma with five large sigillae arranged in a triangular formation Embolus is weakly curved and possesses a thick base. Tegulum with a “hood” (Fig. 3A). Tibial apophyses are well developed, VTA present, either free (Fig. 3A) or hook-shaped and attached to RTA (Fig. 7A). Epigynum highly variable, spermatheca rounded or oval, single pair (Fig. 3C, D). Species composition. Nyctimus bistriatus Thorell, 1877 (♂♀), Nyctimus falcatus Benjamin & Dhiya’ulhaq, sp. nov. (♂), Nyctimus kinabaluensis Benjamin & Dhiya’ulhaq, sp. nov. (♂♀), Nyctimus mutilloides Benjamin & Dhiya’ulhaq, sp. nov. (♂), Nyctimus quadripunctatus Dhiya’ulhaq & Benjamin, sp. nov. (♂♀), Nyctimus rendang Dhiya’ulhaq & Benjamin, sp. nov. (♂♀), Nyctimus saksang Dhiya’ulhaq & Benjamin, sp. nov. (♂), Nyctimus trimeni (Simon, 1895). Nyctimus bistriatus Thorell, 1877 Figs 1–3 Nyctimus bistriatus Thorell, 1877: 499; Lehtinen 2016: 166 (as Nyctimus binotatus, lapsus). Zametopias speculator Thorell, 1892: 123. Type material. Holotype. Indonesia – Sulawesi, Southeast Sulawesi Province • ♂; Kendari; 1874; O. Beccarii leg.; holotype of Nyctimus bistriatus Thorell, 1877; MCSN. Examined. Other material examined. Brunei – Tutong District • 1♂; Bukit Sulang; 1982; N. Stork leg.; canopy fogging in primary forest; RMNH RMNH.ARA.17873. Indonesia – Sumatra, Jambi Province • 1♀; Sarolangun, Bukit Duabelas National Park; 01°58'55.2"S, 102°45'02.6"E; elev. 73 m; 7 Oct. 2013; J. Drescher leg.; canopy fogging in rainforest; GOET 2013_BF2.1_AraThom051N_001 (to be transferred to MZB). Malaysia – Sabah State • 1♂; Kinabalu National Park, Poring Hot Springs; 05°59'N, 116°42'E; elev. 600–700 m; 27 Feb. 1996; A. Floren leg.; canopy fogging on Aporosa lagenocarpa tree, in primary forest; RMNH RMNH.ARA.17874. • 1♀; Kinabalu National Park, Poring Hot Springs; 05°59'N, 116°42'E; elev. 600–700 m; 28 Mar. 1998; A. Floren leg.; canopy fogging on Barringtonia tree, in primary forest; RMNH RMNH.ARA.17875. • 1♂; Kinabalu National Park, Poring Hot Springs; 05°59'N, 116°42'E; elev. 600–700 m; 28 Mar. 1998; A. Floren leg.; canopy fogging on Dacryodes laxa tree, in primary forest; RMNH RMNH.ARA.17876. Diagnosis. Males can be easily distinguished from all other congeners by the longer embolus, more than length of cymbium (in all congeners, the embolus is at most half the length of cymbium; Fig. 3A, B) and the denticulate RTA. Fe- 99 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 1. Nyctimus bistriatus Thorell, 1877 from Borneo; habitus, dorsal view. A. Male (RMNH.ARA.17873); B. Female (RMNH.ARA.17875). Scale bars: 0.5 mm. males can be easily distinguished by the single CO; CD arched, resembling a rams’ horn, more than twice the length of spermathecae (in all congeners, the CO is paired, and the CD are not longer than spermathecae; Figs 2C, D, 3C, D). Description. Male (RMNH.ARA.17873; Figs 1A, 3A, B). Total length 2.85. Prosoma length 1.42; width 1.26. Opisthosoma length 1.43; width 1.17. Diameter of eyes: AME 0.09; ALE 0.15; PLE 0.14 PME 0.07. Interdistances between eyes: AME–AME 0.50; AME–ALE 0.10; ALE–ALE 0.86; PME–PME 0.70; PME–PLE 0.20; ALE–PLE 0.18; AME–PME 0.13; PLE–PLE 1.09. Leg measurements: leg I 3.3 (1.0, 0.5, 1.0, 0.8, 0.5). Prosoma cuboid, almost as long as wide; dorsally blackish brown, surface granulated; laterally with two rows of long, curved macrosetae originating on small tubercles. All eyes are very far apart, especially between the median eyes. Chelicerae, labium and sternum blackish brown; sternum with small dents. Legs dark brown except femora III and IV, which are 100 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 2. Nyctimus bistriatus Thorell, 1877 female from Sumatra (2013 BF2.1 AraThom051N 001). A. Habitus, dorsal view; B. Prosoma, frontal view; C. Epigynum, ventral view; D. Epigynum, dorsal view, cleared. Scale bars: 1 mm (A); 0.5mm (B); 0.2 mm (C, D). yellow; femora and tibiae I–IV with two long spines; patellae I–IV with one distal long spine. Opisthosoma dorsally greyish black with many long setae; five large sigillae present, arranged in a triangular formation; venter greyish black. Palp (Fig. 3A, B): cymbium oval. Embolus long, whip-like, looping over the retro lateral side of bulb, half of its length covered by the cymbium. Tegular hood small, located close to the base of bulb. RTA large, roughly trapezoid, laterally protruding, distal half with denticles on all sides. VTA long, digitiform; apically flexed with tip ventrally curved. Female (RMNH.ARA.17875; Figs 1B, 3C, D). Total length 3.32. Prosoma length 1.15; width 1.30. Opisthosoma length 2.17; width 1.95. Diameter of eyes: AME 0.08; ALE 0.13; PLE 0.16; PME 0.06. Interdistances between eyes: AME– AME 0.56; AME–ALE 0.10; ALE–ALE 0.86; PME–PME 0.64; PME–PLE 0.21; ALE–PLE 0.18; AME–PME 0.16; PLE–PLE 1.09. Leg measurements: leg I 5.3 (1.6, 0.6, 1.3, 1.0, 0.8). Habitus as in male, except opisthosoma dorsally lighter than male and the presence of white spots as shown in Fig. 1B. 101 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 3. Nyctimus bistriatus Thorell, 1877 from Borneo. A. Male (RMNH.ARA.17873), left palp, ventral view; B. ibid., retro lateral view; C. Female (RMNH.ARA.17875), epigynum; C. ibid., ventral view; D. ibid., dorsal view. Abbreviations: CD= copulatory duct; CO = copulatory opening; E = embolus; FD = fertilization duct; RTA = retrolateral tibial apophysis; S = spermatheca; TH = tegular hood; VTA = ventral tibial apophysis. Scale bars: 0.2 mm. Epigynum (Figs 2C, D, 3C, D): exterior plate roughly pentagonal. Atrium inconspicuous. CO oval, single, large, CD long; divided into a very wide, ramshorn-shaped initial part and a narrow, C-shaped later part. Spermatheca globular, approximately as wide as CO; anteriorly with a small bump; posteriorly extended. Distribution. Brunei, Malaysia (Borneo: Sabah), Indonesia (Sumatra: Jambi; Sulawesi: Southeast Sulawesi) (Fig. 19). 102 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Nyctimus falcatus Benjamin & Dhiya’ulhaq, sp. nov. https://zoobank.org/8DF08156-9B26-4343-95A5-641924B7AC50 Fig. 4 Etymology. The species epithet falcatus is derived from the Latin word falx/falcis, meaning “sickle” or “scythe.” It refers to the distinctly curved, sickle-shaped embolus of the male palp, a diagnostic feature of the species. Type material. Holotype. Thailand – Phang Nga Province • ♂; Khao Lak National Park; no more label data; RMNH RMNH.ARA.17861. Diagnosis. Males are very similar to N. saksang sp. nov., in having a similar sickle-shaped embolus, but they can be easily distinguished from it by the Figure 4. Nyctimus falcatus Benjamin & Dhiya’ulhaq, sp. nov., male holotype (RMNH.ARA.17861). A. Habitus, dorsal view; B. Left palp, ventral view; C. Left palpal tibia, retrolateral view. Abbreviations: E = embolus; RTA = retrolateral tibial apophysis; TH = tegular hood; VTA = ventral tibial apophysis. Scale bars: 0.5 mm (A); 0.2 mm (B, C). 103 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 large, digitiform VTA, attached distally on the RTA (the corresponding part in N. saksang, sp. nov., is much smaller and attached medially on the ventral lobe of RTA; Fig. 4B vs Figs 16C, 17A). Description. Male (holotype RMNH.ARA.17861; Fig. 4). Total length: 2.36. Prosoma length 1.23; width: 1.05. Opisthosoma length 1.13; width 1.02. Diameter of eyes: AME 0.08; ALE 0.15; PLE 0.14; PME 0.05. Interdistances between eyes: AME–AME 0.27; AME–ALE 0.08; ALE–ALE 0.59; PME–PME 026; PME– PLE 0.27; ALE–PLE 0.18; AME–PME 0.14; PLE–PLE 0.79. Prosoma cuboid, almost as long as wide, dark reddish brown; surface weakly granulated; laterally adorned with long macrosetae, each arising from a small tubercle. Chelicerae and sternum coloured as prosoma. Front legs brown; back legs brown except for the white femora III and IV. Opisthosoma round, light brown; dorsally covered with scutum; five large sigillae present, arranged in a triangular formation. Palp (Fig. 4B, C): cymbium oval. Embolus sickle-shaped. Tegulum round, with a small triangular projection next to the embolus; tegular hood small. RTA wide trapezoid; VTA large, digitiform, attached distally on the RTA. Female. Unknown. Distribution. Only known from the type locality (Thailand: Phang Nga) (Fig. 19). Remarks. The specimen is partially damaged: both first legs are broken and incomplete, and the remaining legs are mostly missing or fragmented. Nyctimus kinabaluensis Benjamin & Dhiya’ulhaq, sp. nov. https://zoobank.org/1F2D858B-2FED-4397-BE73-9B841300D782 Figs 5–7 Etymology. The specific epithet is derived from the name of the type locality. Type material. Holotype. Malaysia – Sabah State • ♂; Kinabalu National Park, Poring Hot Springs; 05°59'N, 116°42'E; elev. 600–700 m; 27 Feb. 1996; A. Floren leg.; canopy fogging on Barringtonia tree, in primary forest; RMNH RMNH.ARA.17862. Other material examined. Brunei – Tutong District • 1♀; Lamunin, Bukit Sulang; 1982; N. Stork leg.; canopy fogging; RMNH RMNH.ARA.17859. Indonesia – Sumatra, Jambi Province • 1♀; Sarolangun, Bukit Duabelas National Park; 01°58'55.2"S, 102°45'02.6"E; elev. 73 m; 7 Oct. 2013; J. Drescher leg.; canopy fogging in rainforest; GOET 2013_BF2.1_AraThom004N_001 (to be transferred to MZB). Diagnosis. Males can be easily distinguished from all other congeners by the embolic base abruptly bent 90° towards the retrolateral side of the cymbium and the tapered, bent embolus (Fig. 7A, B). Females are distinguishable by the long, oval spermatheca (globular or short-oval in all other congeners; Figs 6C, D, 7C, D). Description. Male (holotype RMNH.ARA.17862; Figs 5A, B, 7A, B). Total length 3.24. Prosoma length 1.61; width 1.50. Opisthosoma length 1.63; width 1.31. Diameter of eyes: AME 0.11; ALE 0.20; PLE 0.17; PME 0.08. Interdistances between eyes: AME–AME 0.44; AME–ALE 0.11; ALE–ALE 0.81; PME–PME 0.45; PME–PLE 0.36; ALE–PLE 0.21; AME–PME 0.17; PLE–PLE 1.15. Leg measurements: leg I 5.0 (1.5, 0.6, 1.3, 1.0, 0.6). Prosoma cuboid, almost as long as wide, dark reddish brown; surface weakly granulated; laterally adorned with long macrosetae, each arising from a small tubercle. Chelicerae and sternum coloured as prosoma. Endites brown with white tip. Front legs 110 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 10. Nyctimus quadripunctatus Dhiya’ulhaq & Benjamin, sp. nov., female paratype (AraThom001N_2013_HF3.2_001). A. Habitus, ventral view; B. Habitus, dorsal view; C. Epigynum, ventral view; D. Epigynum, dorsal view, cleared. Scale bars: 1 mm (A, B); 0.2 mm (C, D). 0.36); leg IV 2.74 (0.83, 0.27, 0.66, 0.52, 0.46). Prosoma cuboid, almost as long as wide, box-shaped, weakly granulated, highest at mid-point, light brown; lateral margins furnished with a row of long macrosetae. Lateral eyes large, situated on tubercles on the lateral edge of the prosoma. Chelicerae, endites, and labium light brown. Sternum light brown. Legs I light brown; others yellow-brown, with sparse spines and black setae. Opisthosoma oval, brown, with two pairs of large white spots. Spinnerets brown. 111 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 11. Nyctimus quadripunctatus Dhiya’ulhaq & Benjamin, sp. nov. A. Male holotype (AraThom001N_2013_HF3.2_001), right palp, mirrored, ventral view; B. ibid., RTA, ventro-retrolateral view; C. Female paratype (AraThom001N_2013_ HF3.2_001), epigynum, ventral view; D. ibid., dorsal view. Abbreviations: CD = copulatory duct; CO = copulatory opening; E= embolus; RTA = retrolateral tibial apophysis; S = spermatheca; TH = tegular hood; VH = ventral hook. Scale bars: 0.2 mm. Palp (Figs 9C, D, 11A, B): cymbium oval. Embolus sickle-shaped; base slightly wrinkled. Tegular hood very wide. RTA large, rectangular, anvil-shaped; dorsally bifurcated, ending into two long, acute lobes, hidden behind a brush of setae; VTA hook-shaped attached medially on RTA. Female (paratype 2013_HF3.2_AraThom001N_002; Figs 10, 11C, D). Total length 4.81. Prosoma length 1.95; width 1.77. Opisthosoma length 2.86; width 2.65. Diameter of eyes: AME 0.09; ALE 0.20; PLE 0.18; PME 0.07. Interdis tances between eyes: AME–AME 0.53; AME–ALE 0.14; ALE–ALE 0.97; PME–PME 0.52; PME–PLE 0.39; ALE–PLE 0.23; AME–PME 0.24; PLE–PLE 1.37. Leg mea- 112 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 12. Nyctimus quadripunctatus Dhiya’ulhaq & Benjamin, sp. nov., non-type male specimen from Borneo (RMNH. ARA.17857). A. Habitus, dorsal view; B. Left palp, ventral view; C. Left palpal tibia, retrolateral view. Abbreviations: E = embolus; RTA = retrolateral tibial apophysis; TH = tegular hood; VH = ventral hook. Scale bars: 0.5 mm (A); 0.2 mm (B, C). surements: leg I 5.47 (1.66, 0.57, 1.34, 1.13, 0.77); leg II -; leg III 3.69 (1.22, 0.47, 0.87, 0.63, 0.50); leg IV 4.12 (1.36, 0.46, 0.96, 0.76, 0.58). Habitus as in males, except prosoma and leg I reddish brown. Epigynum (Figs 10C, D, 11C, D): exterior plate large, hexagonal-shaped with wide anterior side. Atrium conspicuous, inverted heart-shaped with a separation in the middle. CO diagonally oriented, posteriorly facing. CD arch-shaped. Spermatheca elongated, peanut-shaped, with a small bump anteriorly. Distribution. Malaysia (Borneo: Sabah); Indonesia (Sumatra: Jambi) (Fig. 19). Remarks. Specimens from Borneo show slight differences in shape of embolus and dorsal tip of RTA (Fig. 12B, C). 113 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Nyctimus rendang Dhiya’ulhaq & Benjamin, sp. nov. https://zoobank.org/D674C659-6FE3-41A2-9484-300E4C2A918D Figs 13–15 Etymology. The specific epithet refers to a meat dish associated with the cuisine of the Minangkabau people from West Sumatra. The meat is slow-cooked in a plethora of spices, giving it a dark colouration. The dark colour of N. rendang, sp. nov., is reminiscent of the colour of this dish. Type material. Holotype. Indonesia – Sumatra, Jambi Province • ♂; Sarolangun, Air Hitam, Desa Baru; 02°01'49.5"S, 102°46'14.8"E; elev. 57 m; 12 Jul. 2013; J. Drescher leg.; canopy fogging in jungle rubber plantation; GOET 2013_BJ6.1_ AraThom010N_001 (to be transferred to MZB). Paratypes. Indonesia – Sumatra, Jambi Province • 1♂1♀; same data as holotype; GOET 2013_BJ6.1_AraThom010N_002, 003 (to be transferred to MZB). • 2♂♂; 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_HJ4.2_AraThom010N_001, 002 (to be transferred to ZMH). Other material examined. Indonesia – Sumatra, Jambi Province • 1♀; Batang Hari, Hutan Harapan Conservation Area; 02°11'15.3"S, 103°20'36.0"E; elev. 69 m; 7 Aug. 2013; J. Drescher leg.; canopy fogging in rainforest; GOET 2013_HF4.1_AraThom036N_001. Diagnosis. Males are similar to N. quadripunctatus, sp. nov., in having a sickle-shaped embolus and in the general shape of the bulb, but the VTA is digitiform and free (Fig. 15A, B; vs hook-shaped, attached to RTA in N. quadripunctatus, Fig. 11A, B) and the RTA possesses a pillar-shaped ventral lobe and paired, thick spines (vs both absent). Females are distinct in having the spermathecae with a posterior extension and a short, barely noticeable CD (Fig. 11D). Description. Male (holotype 2013_BJ6.1_AraThom010N_001; Figs 13, 15A, B). Total length 2.41. Prosoma length 1.16; width 1.03. Opisthosoma length 1.25; width 1.21. Diameter of eyes: AME 0.07; ALE 0.15; PLE 0.14; PME 0.05. Interdistances between eyes: AME–AME 0.35; AME–ALE 0.08; ALE–ALE 0.62; PME–PME 0.32; PME–PLE 0.24; ALE–PLE 0.17; AME–PME 0.19; PLE–PLE 0.77. Leg measurements: leg I 3.36 (0.90, 0.29, 0.92, 0.75, 0.50); leg II 3.46 (1.04, 0.32, 0.84, 0.75, 0.51); leg III 2.11 (0.67, 0.20, 0.54, 0.38, 0.32); leg IV 2.25 (0.75, 0.18, 0.59, 0.42, 0.31). Prosoma cuboid, almost as long as wide, dark reddish brown; surface weakly granulated; laterally adorned with long macrosetae, each arising from a small tubercle. Chelicerae, and sternum coloured as prosoma. Endites brown with white tip. Front legs brown; back legs brown except for the white femora. Opisthosoma round, dark brown with paired white bars in the middle; dorsally covered with scutum; five large sigillae present, arranged in a triangular formation. Palp (Figs 13C, D, 15A, B): cymbium oval. Embolus sickle-shaped. Tegulum with a small triangular projection next to the embolus; tegular hood small. RTA bilobed; ventral lobe finger-shaped; dorsal lobe wide trapezoid, apically with a pair of short, thick spines. VTA long, finger-shaped, apically flexed. Female (paratype AraThom010N_2013_BJ6.1_003; Figs 14, 15C, D). Total length 3.86. Prosoma length 1.67; width 1.43. Opisthosoma length 2.19; width 2.21. Diameter of eyes: AME 0.08; ALE 0.18; PLE 0.19; PME 0.07. Interdis tances between eyes: AME–AME 0.55; AME–ALE 0.12; ALE–ALE 0.90; PME–PME 114 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 13. Nyctimus rendang Dhiya’ulhaq & Benjamin, sp. nov., male holotype (AraThom010N_2013_BJ6.1_001). A. Habitus, dorsal view; B. Habitus, ventral view; C. Left palp, ventral view; D. Left palp, retrolateral view. Scale bars: 1 mm (A, B); 0.2 mm (C, D). 115 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 14. Nyctimus rendang Dhiya’ulhaq & Benjamin, sp. nov., female paratype (AraThom010N 2013 BJ6.1 003). A. Habitus, dorsal view; B. Habitus, ventral view; C. Epigynum, ventral view; D. Epigynum, dorsal view; E. Epigynum, dorsal view, cleared. Scale bars: 1 mm (A, B); 0.2 mm (C–E). 116 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 15. Nyctimus rendang Dhiya’ulhaq & Benjamin, sp. nov. A. Male holotype (AraThom010N 2013 BJ6.1 001), left palp, ventral view; B. ibid., left palp, retrolateral view; C. Female paratype (AraThom010N_2013_BJ6.1_003), epigynum, dorsal view; D. ibid., epigynum, ventral view. Abbreviations: CO = copulatory opening; E = embolus; PE = posterior extension of spermatheca; RTA = retrolateral tibial apophysis; SP = spine; S = spermatheca; TH = tegular hood; VTA = ventral tibial apophysis. Scale bars: 0.2 mm. 0.45; PME–PLE 0.34; ALE–PLE 0.23; AME–PME 0.23; PLE–PLE 1.11. Leg measurements: leg I 4.85 (0.71, 1.01, 1.18, 0.49, 1.46); leg II -; leg III 3.05 (1.00, 0.30, 0.75, 0.54, 0.46); leg IV 3.41 (1.14, 0.32, 0.83, 0.65, 0.47). Habitus as in male, except opisthosoma not covered in scutum. Epigynum (Fig. 14C, D, 15C, D): exterior plate with irregular border. Atrium inconspicuous. CO semicircular, posteriorly facing. CD very short. Spermatheca oval, anteriorly with a large bump, posteriorly extended. 117 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Distribution. Indonesia (Sumatra: Jambi) (Fig. 19). Remarks. One specimen shows rounded rather than oval spermathecae (Fig. 14E) and is, thus, tentatively placed here, as no males from the same locality were found. Nyctimus saksang Dhiya’ulhaq & Benjamin, sp. nov. https://zoobank.org/D731CC5A-13CF-480B-9894-01BCC9A42F9E Figs 16, 17 Etymology. The specific epithet refers to a meat-stew dish associated with the Batak people from North Sumatra. The meat is cooked in blood, giving it a dark colouration. The dark colour of Nyctimus saksang Benjamin & Dhiya’ulhaq, sp. nov., is reminiscent of the colour of this dish. Type material. Holotype. Indonesia – Sumatra, Jambi Province • ♂; Batang Hari, Hutan Harapan Conservation Area; 02°09'48.9"S, 103°20'04.4"E; elev. 73 m; 6 Jul. 2013; J. Drescher leg.; canopy fogging in rainforest; GOET 2013_ HF2.1_AraThom036N_001 (to be transferred to MZB). Diagnosis. Males can be easily distinguished from all other congeners by the very wide, axe-shaped RTA which consists of three large lobes (Figs 16C, D, 17). Description. Male (holotype 2013_HF2.1_AraThom036N_001; Figs 16, 17). Total length 3.11. Prosoma length 1.50; width 1.25. Opisthosoma length 1.61; width 1.40. Diameter of eyes: AME 0.08; ALE 0.17; PLE 0.14; PME 0.05. Interdistances between eyes: AME–AME 0.40; AME–ALE 0.10; ALE–ALE 0.73; PME–PME 0.38; PME–PLE 0.33; ALE–PLE 0.21; AME–PME 0.22; PLE–PLE 0.95. Leg measurements: leg I 4.20 (1.20, 0.44, 1.05, 0.89, 0.62); leg II 3.74 (1.10, 0.34, 0.91, 0.78, 0.61); leg III 2.78 (0.83, 0.37, 0.67, 0.52, 0.39); leg IV 2.87 (0.88, 0.26, 0.70, 0.60, 0.43). Prosoma cuboid, almost as long as wide, dark reddish brown; surface weakly granulated; laterally adorned with long macrosetae, each arising from a small tubercle. Chelicerae and sternum coloured as prosoma. Endites brown with white tip. Front legs brown; back legs brown except for the white femora. Opisthosoma round, dark brown with paired white bars in the middle that are almost touching each other; anteriorly with a white border; posteriorly with a white patch; dorsally covered with scutum; five large sigillae present, arranged in a triangular formation. Palp (Figs 16C, D, 17): cymbium oval. Embolus elongated, tapering; tip with a slight flange. Tegular hood small. RTA trilobed; ventral lobed finger-shaped; median lobe triangular, with dorsal lobe axe-shaped; dorsal edge slightly folded. VTA hook-shaped, small, attached medially on the ventral lobe of RTA. Female. Unknown. Distribution. Only known from the type locality (Indonesia: Sumatra: Jambi) (Fig. 19). Zametopina Simon, 1909 Type species. Zametopina calceata Simon, 1909. Diagnosis. Zametopina is similar to Nyctimus in habitus, differing in the presence of a unique denticulate process next to the embolus on the male palp 118 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 16. Nyctimus saksang Dhiya’ulhaq & Benjamin, sp. nov. male holotype (AraThom036N 2013 HF2.1 001). A. Habitus, dorsal view; B. Habitus, ventral view; C. Left palp, ventral view; D. Left palp, retrolateral view. Scale bars: 1 mm (A, B); 0.2 mm (C, D). 119 ZooKeys 1255: 95–125 (2025), DOI: 10.3897/zookeys.1255.158380 Suresh P. Benjamin et al.: Taxonomic notes on the crab-spider genera Nyctimus Thorell, 1877 and Zametopina Simon, 1909 Figure 17. Nyctimus saksang Dhiya’ulhaq & Benjamin, sp. nov. male holotype (AraThom036N 2013 HF2.1 001). A. Left palp, ventral view; B. Left palp, retrolateral view. Abbreviations: DL = dorsal lobe; E = embolus; ML = medial lobe; RTA = retrolateral tibial apophysis; TH = tegular hood; VTA = ventral tibial apophysis; VL = ventral lobe. Scale bar: 0.2 mm. (DP in Fig. 18B). No other oriental thomisid genus possesses this structure. For a detailed diagnosis see Tang et al. (2010). Species composition. Zametopina calceata Simon, 1909 and Zametopina wanliae Lin & Li, 2023. Zametopina calceata Simon, 1909 Zametopina calceata Simon, 1909: Simon 1909: 123; Tang et al. (2010): 66, figs 1−18. Type material. Holotype. Vietnam – Cao Bằng Province • ♂; “Boa Luc, dans Haut-Tonkin, à l’Ouest de Cao-Bang et prés la frontière du Yun-Nan et du Kuang-Si” (probably Bảo Lạc District); 1906 or 1907; de Pelacot leg.; MNHN 22937. Examined. Diagnosis. See Lin et al. (2023). Description. See Tang et al. (2010). Distribution. China (Yunnan), Vietnam (Cao Bằng) (Fig. 19). Zametopina wanliae Lin & Li, 2023 Fig. 18 Zametopina wanliae Lin & Li, 2023 in Lin et al. (2023): 79, figs 68A, B, 69I.