Ambohima vato, Griswold & Wood & Carmichael, 2012

Griswold, Charles E., Wood, Hannah Marie & Carmichael, Anthea D., 2012, The lace web spiders (Araneae, Phyxelididae) of Madagascar: phylogeny, biogeography and taxonomy, Zoological Journal of the Linnean Society 164 (4), pp. 728-810 : 793-794

AMBOHIMA VATO SP. NOV.

( FIGS 6C , 7C , 14A–C , 33A–C , 36D, F , 37D, F , 43G–I , 58)

Types: Holotype male and paratype female ( CASENT9020002 ) collected in montane rainforest at 1550 m elevation in Forêt d’Atsirakambiaty , 7.6 km 285° WNW Itremo, 20°35′36″ S, 046°33′48″ E, Fianarantsoa Province, Madagascar, 22–26 January 2003, C. Griswold, D. Silva, and J. J. Rafonomezantsoa, deposited in CASC.

Etymology: The specific name is from the Malagasy word for rock; a noun in apposition.

Diagnosis: Male with palp as in Figure 14A–C , embolic base with a raised, distal cone, cymbium small, cymbium length less than 0.75 times carapace length; palpal tibial prolateral hook short and broad. The cymbial length of A. vato overlaps with that of some A. sublima specimens from Fianarantsoa Province, but males of A. vato may be distinguished by their smaller size and shorter legs, femur I length less than 2.5 times carapace length (compare Fig. 6C with 6F). Female vulva as in Figures 33B and 37D, F , base bilobed, anteriorly with three or fewer tight, transverse coils.

Note: Individuals from the Itremo massif resemble A. sublima in male and female genitalia such that diagnosis is difficult. The molecular phylogeny places these in a species group distant from A. sublima so that we describe the new species A. vato to accommodate the Itremo population.

Male (Holotype): Total length 6.70. Markings similar to Figure 6C . Carapace 3.10 long, 2.40 wide; thoracic fovea 0.60 long, length 0.19 carapace; clypeus 0.28 high; ocular area 0.37 long, 0.89 wide; ratio of eyes AM/AL/PM/PL, 1.06:2.40:1.26:1.00, diameter of PM 0.19. Chelicerae 1.32 long, slender, smooth, promargin of fang furrow with six teeth, retromargin with four large and one minute teeth. Sternum 1.94 long, 1.64 wide; labium 0.74 long, 0.64 wide; palpal coxa 1.26 long, 0.50 wide. Legs elongate, femur I length 2.29 times carapace length; metatarsi I and II prolateral concavity and clasping spines as in Figure 43G–I , segment slightly swollen basad of cavity. Leg measurements (femur + patella + tibia + metatarsus + tarsus = [total]): I: 7.10 + 1.45 + 7.50 + 7.40 + 2.75 = [26.20]; II: 5.90 + 1.25 + 5.65 + 5.50 + 2.75 = [21.05]; III: 5.00 + 1.15 + 4.15 + 4.65 + 1.95 = [16.90]; IV: 6.40 + 1.25 + 6.05 + 6.70 + 2.45 = [22.85]; palp: 1.65 + 0.55 + 0.55 + (absent) + 1.95 = [4.70]. Palpal femur with probasal row of four thorn-like setae; tibia with dorsal blade (DTA) hatchet-shaped, prolateral hook (PTA) slender, blunt-tipped; cymbium length 1.80 times width, 0.63 length of carapace; palpal bulb as in Figure 14A–C , length 1.75 times width, embolus base with raised cone, reservoir course in embolus base strongly sinuate, space between embolus base and proximal embolic curve 1.15 times embolus base width.

Variation (N = 3): Total length 5.30–6.70; carapace length 1.26–1.29 times width, height 0.28–0.33 times width; PER width 2.22–2.54 times OAL; OQP 0.91– 1.12 times OQA; cheliceral length 4.71–5.00 times clypeal height; retromargin of fang furrow with 5–6 teeth; sternum length 1.18–1.27 times width; femur I length 1.98–2.29 times carapace length; metatarsus I 1.76–2.39 times carapace length; cymbium length 0.63–0.73 times carapace length.

Female (Paratype): Total length 8.20. Markings as in Figure 7C . Carapace 3.50 long, 2.65 wide; thoracic fovea length 0.17 times that of carapace; clypeus 0.28 high; ocular area 0.42 long, 1.13 wide; ratio of eyes AM/AL/PM/PL, 1.33:2.73:1.13:1.00, diameter of PM 0.17. Chelicerae 1.42 long, robust, smooth, promargin of fang furrow with six teeth, retromargin with five teeth. Sternum 1.84 long, 1.48 wide; labium 0.72 long, 0.64 wide; palpal coxa 1.20 long, 0.54 wide. Femur I length 1.75 times carapace length. Palpal femur with four anterobasal thorns. Calamistrum origin at 0.50 from metatarsus base, length 0.30 that of segment. Leg measurements (femur + patella + tibia + metatarsus + tarsus = [total]): I: 6.10 + 1.60 + 5.95 + 5.00 + 2.40 = [21.05]; II: 4.95 + 1.40 + 4.05 + 4.00 + 1.95 = [16.35]; III: 4.05 + 1.20 + 3.10 + 3.30 + 1.70 = [13.35]; IV: 5.15 + 1.30 + 4.40 + 4.50 + 1.90 = [17.25]; palp: 1.55 + 0.60 + 0.85 + (absent) + 1.85 = [4.85]. Epigynum as in Figure 36D ; vulva as in Figure 37D , spermatheca with bilobed basal chamber and three tight distal spirals.

Variation (N = 4): Total length 6.30–8.20; carapace length 1.32–1.44 times width, height 0.34–0.42 times width; PER width 2.53–3.05 times OAL; OQP 1.10– 1.34 times OQA; cheliceral length 4.56–5.25 times clypeal height; pro- and retromargins of fang furrow with 5–7 teeth; sternum length 1.13–1.24 times width; femur I length 1.59–1.74 times carapace length; metatarsus I 1.43–1.54 times carapace length; epigyna as in Figures 33A and 36D, F , vulvae as in Figures 33B and 37D, F .

Natural history: Spiders were collected in montane rainforest, where they make typical Ambohima webs, similar to Figure 2A , beneath bark or fallen objects on the ground.

Distribution: Known only from the type locality in a mountainous region of south-central Madagascar ( Fig. 58).

Material Examined: MADAGASCAR: Fianarantsoa Prov., Forêt d’Atsirakambiaty , 7.6 km 285° WNW Itremo, elev. 1550 m, 20°35′36″S, 046°33′48″E, montane rain forest, 22–26 January 2003, C. Griswold, D. Silva and J. J. Rafonomezantsoa, 1 ♂ holotype , 1 ♀ paratype ( CASENT9020002 ), web in base of fallen palm frond, 1 ♀, CASC ( CASENT9005810 ), together in web in fallen palm frond, 1 ♂, 1 ♀, CASC ( CASENT9005809 ), 3 ♂ 4 ♀, CASC ( CASENT9005936 , 9017395 , 9020003 , 9017304 , 9005975 , 9016756 , 9005552 ) .

Figures

Figure 2. Ambohima sublima. A, web from Andranomay (Joel Ledford photo). B, male from Talatakely (Jeremy Miller photo).

Figure 6. Habitus of Ambohima. A, A. andrefana, male, dorsal, Analavelona, CASENT9020321. B, A. andrefana, male, dorsal, Zombitse, CASENT9005931. C, A. vato, male, dorsal, Itremo, CASENT9016755. D, A. zoky, holotype male, dorsal, CASENT9017018. E, A. sublima, male, dorsal, Ambohimanga, CASENT9016200. F, A. sublima, male, dorsal, Talatakely, CASENT9024485. G, I, A. maizina, holotype male, CASENT9016206. G, dorsal. I, ventral. H, A. ranohira, female, ventral, Ranohira, CASENT9019986.

Figure 7. Habitus of Ambohima females. A, B, A. antsinanana from Andringitra, CASENT9029887. A, dorsal. B, lateral. C, A. vato from Itremo, CASENT9020002, dorsal. D, A. ranohira from Analalava, CASENT9019989, dorsal. E, A. avaratra from Montagne d’Ambre, CASENT9017012, dorsal. F, A. zandry, Montagne d’Ambre, CASENT9017021, dorsal. G, A. zoky, Montagne d’Ambre, CASENT9020320, dorsal. H, A. pauliani, holotype, dorsal.

Figure 14. Left male palpus of Ambohima vato from Itremo (CASENT9005809), tibia and tarsus. A, prolateral. B, ventral. C, retrolateral. Illustrations by GM.

Figure 33. Ambohima female genitalia. A, D, G, epigyna, ventral. B, C, E, F, H, I, vulvae, dorsal. A–C, A. vato, Itremo, CASENT9005552. D–F, A. zoky, Montagne d’Ambre, CASENT9017016. G–I, A. antsinanana, Andringitra, CASENT9029887. CD: copulatory duct, FD: fertilization duct, SP: spermathecal poreplate.

Figure 36. Epigyna of Ambohima, ventral view. A, A. zoky, Montagne d’Ambre, CASENT9020320. B, A. antsinanana, Andringitra, CASENT9029888. C, A. pauliani, holotype. D, A. vato, Itremo, CASENT9020002. E, A. zoky, Montagne d’Ambre, CASENT9017014. F, A. vato, Itremo, CASENT9005552. Scale bar applies to all images.

Figure 37. Vulvae of Ambohima, dorsal view. A, A. zoky, Montagne d’Ambre, CASENT9020320. B, A. antsinanana, Andringitra, CASENT9029888. C, A. pauliani, holotype. D, A. vato, Itremo, CASENT9020002. E, A. zoky, Montagne d’Ambre, CASENT9017015. F, A. vato, Itremo, CASENT9005552. Scale bar applies to all images.

Figure 43. Ambohima male leg I metatarsal claspers, left. A, D, G, J, M, clasper close up, dorsal. B, E, H, K, N, metatarsus, dorsal. C, F, I, L, O, clasper close up, prolateral. A–C, A. sublima, Andranomay, CASENT9004080. D–F, A. sublima, Talatakely, CASENT9016994. G–I, A. vato, Itremo, CASENT9005809. J–L, A. zandry, Montagne d’Ambre, CASENT9003543. M–O, A. zoky, Antsiranana, CASENT9017018.