Bioacoustics of Kambiwa

Description Males MEASUREMENTS . Total body length 0.9–1.3; carapace width 0.45–0.55. PME diameter 45–55 µm; AME diameter 20–35 µm. Leg 1 length 2.1–2.7; tibia 1 length 0.5–0.7; metatarsus 1 approximately same length as tibia 1 (metatarsus 1/ tibia 1 length: 0.96–1.06); tibia 4 longer than tibia 1 (tibia 4 / tibia 1 length: 1.1–1.3); leg femora diameters 110–120 µm; leg tibiae diameters 65–70 µm. Tibia 1 L/d 8–10. COLOR . In ethanol mostly ochre-yellow to light brown, carapace without dark marks but sometimes medially slightly darker, legs without dark rings; abdomen sometimes pale gray, sometimes with darker internal marks dorsally and laterally; ventrally with light ochre to brown plate in front of gonopore. Live specimens often with slightly reddish or orange prosoma and legs ( Fig. 2 ). BODY . Habitus as in Fig. 2 . Ocular area not or barely raised. Carapace usually without thoracic groove ( Fig. 3A–B ), with shallow groove in K. itacarambi sp. nov. ( Fig. 3C ). Clypeus unmodified. Sternum slightly wider than long, with pair of low but distinct anterior processes near coxae 1 ( Fig. 3F–G ); processes without pores. Abdomen globular. Gonopore usually with four epiandrous spigots in two pairs ( Fig. 4A–C ), in K. maracas sp. nov. apparently without epiandrous spigots ( Fig. 4D ). General arrangement of spinnerets as usual in Pholcidae (cf. female, Fig. 5A ); ASL with seven spigots each: one strongly widened spigot, one long and slender spigot, and five cylindrical spigots (of which one is much wider than the others) ( Fig. 5 ); PMS with two short conical spigots ( Fig. 5 ); PLS with strong hairs but without spigots. CHELICERAE . Usually with pair of small frontal apophyses (e.g., Fig. 17A–B ), only in K. itacarambi sp. nov. without apophyses but with sclerotized ridge followed distally by whitish area ( Fig. 40A–B ). Stridulatory files ( Fig. 6 ) usually fine but distinct, only in K. itacarambi very indistinct and not visible under dissecting microscope; with ~30–65 ridges, distances between ridges (in five species studied with SEM) mostly 1.3–1.8 µm, only in K. ibo sp. nov. wider (2.4 µm); distances between ridges very homogenous throughout file. PALPS . Coxa unmodified; trochanter with indistinct ventral protrusion; femur proximally with small ventral conical process, distally widened but otherwise unmodified; femur-patella condyles not or slightly shifted toward prolateral side; tibia almost globular, with two trichobothria; tibia-tarsus condyles not or slightly shifted toward retrolateral side; palpal tarsal organ capsulate with small opening ( Fig. 7A–D ), as long or slightly longer than wide, outer diameter 6–8 µm, opening diameter 0.8–1.2 µm; procursus short and simple, shape variable (e.g., Figs 16A–C , 22A–C ), in K. ibo sp. nov. and K. sapo with small spikes on distal membranous flap ( Figs 43A–C , 46A–C ); genital bulb complex, with proximal sclerite connecting to tarsus; bulbous part of genital bulb with distinctive ventral process and variably complex dorsal processes including membranous and sclerotized elements (e.g., Figs 16D–F , 22D–F ), retrolateral-dorsal sclerite in some species strongly elongated (e.g., Fig. 31D–F ); sperm duct opening not located (presumably among membranous elements of dorsal bulbal process). LEGS . Without spines; without curved hairs. Tibia 1 or tibia 1 +tibia 2 with sexually dimorphic short ‘vertical’ hairs ( Fig. 8D–F ), in several rows or bands, base diameter 4–5 µm, length 15–20 µm, diameter at half-length 0.7–0.8 µm. Distal leg segments (tarsi and metatarsi) with putative chemoreceptors ( Fig. 10A– B ), in light microscope similar to sexually dimorphic short vertical hairs but with one or two distal side branches, with one or two oblique furrows, and distally flattened (i.e., with oval diameter); base diameter ~4.5–5.0 µm, length 15–20 µm, diameter proximally 1.5–1.7 µm. Femora, tibiae, metatarsi, and tarsi with round or oval cuticular plates ( Fig. 8A, E ) at regular intervals, diameter ~5–7 µm. Rimmed pores ( Fig. 8A–B ) at regular intervals, mainly dorsally on tibiae, metatarsi, and tarsi; outer diameter 2.5–2.7 µm; opening diameter: 0.3–0.4 µm. Base of trichobothria round or with pair of indistinct lateral humps ( Fig. 8C ); outer diameter of base: 10–14 µm; proximal diameter of seta: 1.3–1.4 µm; retrolateral trichobothrium on tibia 1 at 56–62% of tibia length; prolateral trichobothrium absent on tibia 1. Without slender metatarsal hairs (as described in Huber et al. 2023c , 2024d ). Tarsi with 4–5 pseudosegments, only distally 2–3 distinct. Leg tarsal organs capsulate with small opening ( Fig. 9 ), outer diameter 3–6 µm, opening diameter 0.8–1.1 µm. Tarsus 4 with two comb hairs distally on prolateral side ( Fig. 10F ). Tarsal claws as usual for family ( Fig. 10 ); main claws with 8–10 teeth; teeth on tarsus 4 slightly different (shorter and directed more towards distal). Females In general, very similar to males, but legs on average slightly shorter than in males (male /female tibia 1 length: ~1.0–1.1), without sexually dimorphic short vertical hairs on tibiae, without humps on sternum, and without stridulatory files on chelicerae ( Fig. 6B, F ). Palpal tarsal organ as in males but slightly less elevated ( Fig. 7E–F ), outer diameter 5.5–6.5 µm, opening diameter 0.8–1.0 µm. Other sensory organs and comb hairs on tarsus 4 as in males. Spinnerets as in males. Tip of palp with simple pointed process ( Fig. 7E–F ). Epigynum anterior plate usually trapezoidal to semicircular (e.g., Figs 18A , 24A , 33A ), only in K. itacarambi sp. nov. rather arc-shaped ( Fig. 41A ), without processes or pockets. Posterior epigynal plate relatively large but simple, unmodified. Internal genitalia with straight or curved or bent transversal sclerite, without or with very small and indistinct pore plates (e.g., Figs 24G , 29F , 33F ), in most species with median anterior modification (e.g., Figs 17C , 23C ; absent in K. itacarambi and K. ibo sp. nov. ); some species with median membranous sac, others with long membranous tube ( Figs 28C , 32C , 36C ) possibly functionally correlated with long retrolateral-dorsal sclerite of genital bulb. Relationships The latest molecular phylogeny of Pholcidae ( Meng et al. 2025 ) has a dense taxon sampling of Ninetinae , including the genera Kambiwa , Galapa and Sertana gen. nov. The relationships among these Neotropical genera is resolved as ( Kambiwa ( Galapa , Sertana )) (inset in Fig. 1 ). This is in contrast with our CO1 tree ( Fig. 1 ), but the tree in Meng et al. (2025) is based on a large number of genes and thus much more likely to reflect phylogeny. The topology in Meng et al. (2025) is also confirmed in an upcoming, even larger dataset combining the UCA data of Meng et al. (2025) with results from low coverage genome sequencing (G. Meng, L. Podsiadlowski, B.A. Huber, unpubl. data). This new dataset also includes Kambiwa ibo sp. nov. , which is resolved as sister to all other species of Kambiwa ; the monophyly of Kambiwa receives maximum support. Thus, the paraphyly of Kambiwa shown in our CO1 tree ( Fig. 1 ) is very probably an artifact.