Chibchea hamadae Huber & Carvalho, 2019

Huber, Bernhard A. & Carvalho, Leonardo S., 2019, Filling the gaps: descriptions of unnamed species included in the latest molecular phylogeny of Pholcidae (Araneae), Zootaxa 4546 (1), pp. 1-96 : 49

Chibchea hamadae Huber & Carvalho sp. n.

Figs 152–153 , 160, 163 , 165, 168 , 175–176

Type material. BRAZIL: ♂ holotype, UFMG (22736) , 1♂ 3♀ paratypes, UFMG (22051, 22737); 1♂ 2♀ paratypes, CHNUFPI (2522); and 1♂ 1♀ paratypes, ZFMK (Ar 20630), Amazonas, Manaus, Reserva Florestal Adolpho Ducke (2.932°S, 59.970°W), 80 m a.s.l., 5–6.xi.2016 (B.A. Huber, L.S. Carvalho).

Other material examined. BRAZIL: 2♂ 3♀, CHNUFPI (2480, 2485, 2524, 2527, 2531) ; 4♂ 2♀, UFMG (21861, 22050, 22052, 22614, 22618); and 1 juv., ZFMK (Br16-335), all in pure ethanol, same data as holotype .

Etymology. The species is named for the Brazilian entomologist Neusa Hamada (INPA), in recognition of her help with logistics during our 2016 Amazon expedition.

Diagnosis. Distinguished from most similar known congeners ( C. santosi , C. valle , C. amapa ) by shapes of procursus and bulbal apophysis ( Figs 160, 163 ; bulbal process without ventral sclerite proximally, with indistinct dorsal membranous process; procursus tip not bifid, wider than in C. santosi ), by shape of process proximally on male palpal femur ( Fig. 165 ; similar to C. santosi but with additional rounded process), and by external and internal female genitalia ( Figs 168 , 175–176 ; epigynal plate trapezoidal, slightly wider anteriorly than posteriorly, without posterior processes; oval pore plates far apart).

Description. Male (holotype). MEASUREMENTS. Total length 2.25, carapace width 0.85. Distance PME-PME 80 µm; diameter PME 90 µm; distance PME-ALE 60 µm; distance AME-AME 15 µm, diameter AME 20 µm. Leg 1: 19.2 (4.4 + 0.3 + 4.7 + 8.6 + 1.2), tibia 2: 2.9, tibia 3: 2.4, tibia 4: 2.9; tibia 1 L/d: 67.

COLOR (in ethanol). Carapace pale ochre-yellow with indistinct pattern of brown median mark including ocular area and brown lateral marginal bands; clypeus with pair of brown marks below eye triads; sternum brown; legs light brown, tips of tibiae whitish; abdomen pale greenish to blueish gray with blueish marks dorsally and laterally, ventrally with light brown mark in gonopore area and blueish band between gonopore and spinnerets.

BODY. Habitus as in Fig. 152 . Ocular area slightly elevated. Thoracic furrow present. Clypeus unmodified. Sternum wider than long (0.58/0.40), unmodified.

CHELICERAE. Very similar to C. amapa (cf. Fig. 156 ), pair of processes on fangs mostly on posterior side as in C. santosi (cf. Fig. 157 ; barely visible in frontal view).

PALPS. Very similar to C. amapa (cf. Figs 154–155 ) but femur with additional prolateral-ventral process and proximal retrolateral-ventral process of different shape ( Fig. 165 ); procursus with simple tip, not bifid ( Fig. 160 ); bulbal process slender, without serrated ventral sclerite, with very indistinct membranous dorsal process ( Fig. 163 ).

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium of tibia 1 at 8%; tibia 1 without prolateral trichobothrium (present on other tibiae); tarsus 1 with ~25 pseudosegments, distally distinct.

Male (variation). Tibia 1 in 7 other males: 4.1–4.4 (mean 4.3); one male (UFMK 22618) with much shorter legs (tibia 1: 3.15). Freshly molted adults (and juveniles) are bright purplish.

Female. In general similar to male ( Fig. 153 ) but cheliceral fangs unmodified. Tibia 1 in 9 females: 2.8–4.3 (mean 3.2). Epigynum anterior plate trapezoidal, slightly wider anteriorly than posteriorly, with distinct rugose area in anterior part ( Fig. 175 ); internal arc visible through cuticle along anterior margin of anterior plate; apparently without pockets; posterior plate simple, weakly sclerotized. Internal genitalia with pair of oval pore plates ( Figs 168 , 176 ).

Distribution. Known from type locality in Amazonas state, Brazil, only ( Fig. 346 ).

Natural history. This species was found in tiny webs in small holes in the ground under the leaf litter. It was collected during heavy rainfall and the spiders got immobilized immediately by direct contact with water, which suggests that the spiders depend on spaces in the ground sheltered from water.

Figures

FIGURE 346. Known distribution of Chibchea in Brazil.

FIGURES 148–153. Chibchea spp., live specimens. 148–149. C. amapa sp. n., male and female with egg sac. 150–151. C. santosi sp. n., females with egg sacs. 152–153. C. hamadae sp. n., male and female with egg sac.

FIGURES 156–163. Chibchea spp., chelicerae frontal view and cheliceral fang, posterior view (156–157) (arrows point at processes on fangs), left procursi, retrolateral views (158–160), and left bulbal processes, prolateral views (161–163) (arrow points at distinctive proximal ventral sclerite). 156, 158, 161. C. amapa sp. n. (ZFMK, Ar 20626). 157, 159, 162. C. santosi sp. n. (ZFMK, Ar 20628). 160, 163. C. hamadae sp. n. (ZFMK, Ar 20630). Scale lines: 0.1 (procursi and bulbal processes at same scale each).

FIGURES 164–168. Chibchea spp., male left palpal femora, retrolateral views (164–165), and cleared female genitalia, dorsal views (166–168). 164, 167. C. santosi sp. n. (ZFMK, Ar 20628). 165, 168. C. hamadae sp. n. (ZFMK, Ar 20630). 166. C. amapa sp. n. (ZFMK, Ar 20626). pp, pore plates. Scale lines: 0.2 (femora and cleared epigyna at same scale each).

FIGURES 169–176. Chibchea spp., male in dorsal and lateral views, epigyna in ventral views, and cleared female genitalia in dorsal views. 169–172. C. amapa sp. n. (ZFMK, Ar 20626). 173–174. C. santosi sp. n. (ZFMK, Ar 20628). 175–176. C. hamadae sp. n. (ZFMK, Ar 20630). Scale lines: 0.3 (171–176), 1.0 (169–170).

FIGURES 154–155. Chibchea amapa sp. n. (ZFMK, Ar 20626). Left male palp, prolateral and retrolateral views. Scale line: 0.3.