Cuiambuca Rheims, 2023, gen. nov.

Genus Cuiambuca gen. nov.

urn:lsid:zoobank.org:act: 9C7768E4-C253-4D78-BC03-059DD589F64C

Diagnosis

Species of the genus Cuiambuca gen. nov. resemble those of the genera Decaphora, Rhacocnemis, Stasina, Thelcticopis and Thomasettia by the presence of more than two retromarginal teeth in the chelicerae (5–7 in Decaphora, 6 in Rhacocnemis, 4−5 in Stasina, 5−6 in Thelcticopis, 3 in Thomasettia and 4–5 in Cuiambuca gen. nov.), but are distinguished from Decaphora and Rhacocnemis in having only three promarginal teeth (Fig. 1A) (4 in the latter genera); from Thomasettia in having two straight or slightly procurved eye rows (e.g., Figs 3A, 6A, 8A) and only one pair of ventral spines on metatarsi I−II (recurved eye rows and two pairs of spines in Thomasettia); from Stasina and Thelcticopis in having 3−4 pairs of ventral spines on tibiae I−II (more than 5 pairs in the latter genera). They are further distinguished from all other genera in Sparianthinae by the conductor in the male palp sclerotized with keels and projections at base, ending in a hyaline sheath (Figs 5B, 10B), by the embolus with short, sickle-shaped TBE (Figs 5 D−E, 10D−E), by the female epigyne with a keyhole-shaped MS (Figs 5F, 7A, 10F) and by the vulva with rounded spermathecae and rounded blind ending projections on long and thick stalks (Figs 5G, 7B, 10G).

Etymology

The generic name is a Brazilian noun, derived from the Tupi “ kuyã’buka ”, used for a container made out of a gourd with a circular opening at the top to retain water and other liquids. It refers to the shape of the female vulva and its rounded spermathecae and blind-ending projections. Gender is female; noun in apposition.

Description

Total length of males 6.0−7.7, of females 7.6−9.2. Prosoma longer than wide; cephalic region higher than thoracic region; fovea slightly conspicuous on posterior third of prosoma. Eight eyes arranged in two rows, the anterior row straight, the posterior straight or slightly procurved; AME larger than ALE and more separated from each other than from laterals; PME smaller than PLE and equidistant (Figs 3A, 4A, 6A, 8A, 9A). Clypeus low, less than AME diameter. Chelicerae longer than wide, with three promarginal teeth, the basal one smallest, and 5−6 retromarginal smaller teeth; intermarginal denticles absent; one single retromarginal escort setae at the base of fang (Fig. 1A). Labium slightly longer than wide. Endites convergent with dense scopulae on internal margin. Serrula with a single row of denticles (Fig. 1B). Sternum longer than wide. Female palp with single pectinate claw with 4−5 short, gently curved teeth (Fig. 1D). Legs laterigrade, leg formula: 4123 or 4213. Trochanter smooth. Metatarsi I–IV with distal dorsal trilobate membrane with median hook much smaller than lateral projections (Fig. 1C). Tarsi and anterior half of metatarsi scopulate. Trichobothria present on dorsal tibiae, metatarsi and tarsi, arranged in several rows that converge to one on metatarsi. Trichobothria with well-differentiated proximal and distal plates; proximal plate with several transverse ridges; trichobothrial setae thickened in a basal bulb (Fig. 2A). Tarsal organ capsulate, with round to oval opening (Fig. 2B), located distally on tarsi. Tarsi with pair of pectinate claws, with 11−12 gently curved teeth, inserted medially on proximal half and laterally on distal half of claw; claw tufts with deeply indented setae (Fig. 2C). Spination pattern in males: femora I−III: p1-1-1,d 0-1-1, r1-1-1; femur IV: p1- 1-1, d0-1-1, r0-0-1; patellae I−IV: 0; tibiae I−II: p1-0-1, d0-0-1; r1-0-1; v2-2-2-2 (v2-2- 2 in C. aratangi sp. nov.); tibiae III−IV: p1-0-1, d0-0-1; r1-0-1; v2-2-2; metatarsi I−II: p1-1-1; r1-1-1; v2-0-0; metatarsi III−IV: p1-1-1, r1-1-1, v2-2-0; palp: femur p0-0-1; d0-1-2; patella p1-r1; tibia p2-1-0; in females: femora I−III: p1-1-1, d0-1-1, r1-1-1; femur IV: p1-1-1, d0-1-1, r0-0-1; patellae I−IV: 0; tibiae I−II: v2- 2-2-2 (v2-2- 2 in C. aratangi sp. nov.); tibia III: v2-2-2; tibia IV: p1-0-1, r1-0-1, v1p-2-2; metatarsi I−II: v2-0-0; metatarsus IV: p1-1-1, r1-1-1, v2-2-0; palp: femur p0-0-1; d0-1-2; patella p1; r1; tibia p2-1; d1-1; r1-1; tarsus: p2-1; r2-1. Opisthosoma oval, longer than wide. Male epiandrium with epiandrous spigots arranged in scattered bunches (Fig. 2D). Six spinnerets: anterior lateral spinnerets contiguous, conical and bi-segmented; basal segment elongate and cylindrical, distal segment short and truncated. Posterior median spinnerets conical and short. Posterior lateral spinnerets conical and bi-segmented; basal segment elongate and cylindrical, distal segment short and truncated. Palp: tibia short, roughly half cymbium length, with two prolateral and one dorsal spine; VTA triangular, slightly displaced retrolaterally; RTA single, with two branches, arising medio-proximally from tibia; cymbium with small RpP, large, round alveolus and small rounded dorsal scopula; subtegulum visible in ventral view between 5−6 o’clock; tegulum with hyaline keel along distal margin, fanning out close to C base; MA cup-shaped, arising from tegulum at 4−4:30 o’clock; C arising from tegulum at 3 o’clock position; E filiform, arising from tegulum between 8:30−9 o’clock position (Figs 3 C−E, 5A−E, 8C−D, 10A−E). Epigyne: divided into LL and MS; LL simple, with or without posterior triangular projections, partially covering MS; MS smooth, without projections, longer than wide (Figs 4C, 5F, 6F, 7A, 9C, 10F). Vulva: CD short, opening posteriorly on MS or at lateral margins of LL; SP large and rounded; BP arising from CD at base of SP; antero-mediad (Figs 4D, 5 G−H, 6D, 7B−C, 9D, 10G−H).

Included species

Cuiambuca aratangi sp. nov., C. borborema sp. nov. and C. vacabrava sp. nov.

Distribution

Northeastern Brazil, from Paraíba to Sergipe (Fig. 11).