Indopadilla namkarensis, Hoang, 2025

Hoang, Quang Duy, 2025, Description of a new species of the genus Indopadilla Caleb & Sankaran, 2019 from Vietnam (Araneae: Salticidae), Zootaxa 5637 (1), pp. 190-194 : 191-192

Indopadilla namkarensis sp. nov.

Figs 1–9

Type material. Holotype: ♂ ( VNMN-ARA-SAL-647 ), VIETNAM: Dak Lak Prov.: Lak Dist., Buon Tria Comm., Nam Kar Natural Reserve , 12.3933°N, 108.0002°E, 430 m, 17 Oct. 2024, leg. Q.D. Hoang. Paratypes: 1♀ ( VNMN-ARA-SAL-646 ), 1♂ ( VNMN-ARA-SAL-647.1 ), same data as for holotype.

Etymology. This specific epithet is derived from the type locality, Nam Kar Natural Reserve, where the species was found; noun in apposition.

Diagnosis. The male of Indopadilla namkarensis sp. nov., can be easily distinguished from other congeners by embolus serrated laterally, wide and long ( Figs 4, 5 ) vs. others with smooth, thin and long or wide and short (see comparative illustrations in Metzner 2025). The female closely resembles those of I. phantoani and I. retsivn in having epigyne with short copulatory ducts, and coiled spermathecae, but differs from the latter by the followings: copulatory openings located medially ( Fig. 8 ) vs. posteriorly in both I. phantoani and I. retsivn (fig. 13 in Hoang et al. 2023 and figs 16, 18 in Hoang et al. 2024a), copulatory ducts situated closer together and accompanied fully visible accessory glands dorsally ( Fig. 9 ) vs. far from each other and partially visible in I. retsivn (figs 17, 19 in Hoang et al. 2024a) or invisible in I. phantoani (fig. 14 in Hoang et al. 2023), and the presence of an inverted heart-like epigynal coupling pocket, which is unique within the genus ( Figs 8–9 ) vs. triangular in both I. phantoani and I. retsivn (fig. 13 in Hoang et al. 2023 and figs 16, 18 in Hoang et al. 2024a).

Description. Male (holotype, Figs 1–5 ): Measurements: Total length 5.73; Carapace length 2.58, width 1.99; Abdomen length 3.15, width 1.13. Carapace dark brown, clothed with black setae, present umbelliform yellowish-brown area around fovea and narrow band along thoracic slope medially ( Figs 1–2 ); around eye region surrounded by distinct line of long yellow setae, with cluster of dense yellow setae behind and between the PMEs ( Figs 1, 2 ). Chelicerae dark brown, with four promarginal teeth, and one retromarginal tooth with five cusps ( Fig. 3 ). Abdomen dark brown, covered with dark setae dorsally ( Figs 1–2 ), lateral sides sparsely clothed with yellow setae. Spinnerets dark ventrally. Leg I dark brown, robust and longest; legs II, III and IV pale yellow. Width of eye rows: anterior eye row 1.59; posterior medial eye row 1.36; posterior lateral eye row 1.52. Distance between ALE–PME 0.54; ALE–PLE 1.09. Diameter of eyes: AME 0.59; ALE 0.30; PME 0.07; PLE 0.24. Length of leg segments: I 1.97 + 1.18 + 1.91 + 1.60 + 0.71 (7.37); II 1.32 + 0.77 + 1.02 + 1.01 + 0.45 (4.57); III 1.23 + 0.69 + 0.64 + 0.93 + 0.46 (3.95); IV 1.68 + 0.76 + 1.20 + 1.43 + 0.47 (5.54). Leg formula I–IV–II–III.

Palp ( Figs 4–5 ) Tibia short, approximately one-third cymbial length, with short and blunt dorsal tibia apophysis. Retrolateral tibial apophysis wide, bent ventrad, and with rather blunt tip in the retrolateral view. Posterior tegular lobe narrow, directed postero-retrolaterally. Embolus nearly straight, about half cymbial width, bearing disto-retromarginal denticles, distally bifurcated into sub-triangular prolateral ramus and strongly sclerotized retrolateral ramus slightly curved towards prolateral side, accompanied by terminal tegular apophysis with pointed tip.

Female ( Figs 6–9 ): Measurements: Total length 6.62; Carapace length 2.83, width 2.24; Abdomen length 3.79, width 1.57. Width of eye rows: anterior eye row 1.71; posterior medial eye row 1.47; posterior lateral eye row 1.63. Distance between ALE – PME 0.54; ALE –PLE 1.09. Diameter of eyes: AME 0.67; ALE 0.30; PME 0.07; PLE 0.26. Endites and labium as holotype, medial labium with a dent laterally. Chelicerae same as in holotype. Length of leg segments: I 1.71 + 1.10 + 1.39 + 1.20 + 0.53 (5.93); II 1.34 + 0.88 + 0.96 + 0.93 + 0.43 (4.54); III 1.27 + 0.75 + 0.58 + 0.97 + 0.40 (3.97); IV 1.80 + 0.81 + 1.28 + 1.45 + 0.53 (5.87). Leg formula I–IV–II–III. Habitus almost similar to that of holotype, except leg I lighter.

Epigyne ( Figs 8–9 ) Longer than wide, copulatory openings transverse, slit-like, located mediolaterally. Epigynal coupling pocket located posteriorly and shaped into inverted heart. Copulatory ducts short, upward extended, and nearly parallel, accessory glands fully visible dorsally. Spermathecae almost round and partially overlapping.

Distribution. Known only from the type locality.

Notes. The genetic analysis using a COI dataset of 420 bp from six Indopadilla species is documented in Table 2 . Interspecific genetic distance (K2P model) ranged from 7.27% to 13.91%. The highest interspecies genetic distance was observed between I. namkarensis sp. nov. and I. sabivia (13.91%), while the lowest was between I. phantoani and I. retsivn (7.28%). Intraspecies genetic distance between male and female specimens of I. the new species is 0%, which strongly supports their conspecific status. Genetically, the new species, I. namkarensis sp. nov. is most closely related to I. yokdon , with a genetic distance of approximately 9.56%.

Sympatric occurrences of Indopadilla species have been observed in Chu Yang Sin National Park, Central Highlands of Vietnam, where at least three species coexist within a small area (Q.D. Hoang, personal observation) that suggests the actual diversity of the genus in Vietnam as well as in the Asian region, is likely higher than currently known. Further research is needed to fully document the diversity, particularly to match opposite sexes within each species accurately.

Figures

FIGURES 1–5. Male of Indopadilla namkarensis sp. nov. 1 Habitus in life, dorsal view; 2 Habitus in alcohol, dorsal view; 3 Left chelicera, posterior view (arrows indicated the position of the teeth); 4 Palp, ventral view; 5 Same, retrolateral view. Scale bars: 2 2.0 mm, 3–5 0.2 mm.

FIGURES 6–9. Female of Indopadilla namkarensis sp. nov. 6 Habitus in life, dorsal view; 7 Habitus in alcohol, dorsal view; 8 Epigyne, ventral view; 9 Same, dorsal view. Scale bars: 7 2.0 mm, 8–9 0.2 mm.