Chibchea amapa 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 : 43-45

Chibchea amapa Huber & Carvalho sp. n.

Figs 148–149 , 154–156, 158, 161 , 166 , 169–172 , 189–190

Gen.n. Br16-50: Eberle et al. 2018 (molecular data); Huber et al. 2018: fig. 3.

Type material. BRAZIL: ♂ holotype , 1♀ paratype, UFMG (22732–33), 1♂ paratype, CHNUFPI (2482), and 3♂ 5♀ 4 juvs paratypes, ZFMK (Ar 20626), Amapá, Santana, forest SW Macapá , ‘site 4’, near road AP-010 (0.057°S, 51.234°W), 25 m a.s.l., 13.x.2016 (B.A. Huber, L.S. Carvalho) .

Other material examined. BRAZIL: 2♀, ZFMK (Br 16-252) ; 1♀, CHNUFPI (2491); and 1♂ 1♀, UFMG (21788–89), all in pure ethanol, same data as types . 1♂, CHNUFPI (2487); 4♂, 5♀, 4 juvs, CHNUFPI (2493); 1♀, CHNUFPI (2494); 2♂ 6♀, UFMG (21844); 3♂ 8♀ 2 juvs, ZFMK (Ar 20627); and 4♀ 2 juvs in pure ethanol, ZFMK (Br 16-253), Amapá, Mazagão, forest SW Macapá , ‘site 3’, near road AP-010 (0.138°S, 51.367°W), 25 m a.s.l., 13.x.2016 (B.A. Huber, L.S. Carvalho) .

Etymology. The species name is derived from the type locality; noun in apposition.

Diagnosis. Distinguished from most similar known congeners ( C. valle , C. santosi , C. hamadae ) by shapes of procursus and bulbal apophysis ( Figs 158, 161 ; subdistal ventral sclerite on bulbal process very similar to C. valle but longer; dorsal membranous process smaller than in C. valle and C. santosi ; procursus distally bifid as in C. valle ), by large rounded process proximally on male palpal femur ( Fig. 155 ), and by external and internal female genitalia ( Figs 166 , 171–172 ; epigynal plate with pair of distinct processes; round pore plates close together; female of C. valle unknown).

Description. Male (holotype). MEASUREMENTS. Total length 1.6, carapace width 0.70. Distance PME-PME 70 µm; diameter PME 70 µm; distance PME-ALE 60 µm; distance AME-AME 15 µm, diameter AME 20 µm. Leg 1: 12.7 (2.9 + 0.3 + 3.2 + 5.4 + 0.9), tibia 2: 1.9, tibia 3: 1.7, tibia 4: 2.1; tibia 1 L/d: 58.

COLOR (in ethanol). Carapace pale ochre-yellow with brown median mark including ocular area (except medially) 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. 148 . Ocular area slightly elevated. Thoracic furrow present. Clypeus unmodified. Sternum wider than long (0.54/0.32), unmodified.

CHELICERAE. As in Fig. 156 , barely modified, with pair of indistinct processes on fangs.

PALPS. As in Figs 154–155 ; coxa with small retrolateral apophysis, trochanter barely modified, femur with large retrolateral-ventral process proximally and rounded unsclerotized projection distally; procursus simple, distally bifid ( Fig. 158 ); bulbal process with slightly serrated ventral sclerite, thin distal sclerotized process, and membranous dorsal process ( Fig. 161 ).

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium of tibia 1 at 10%; tibia 1 without prolateral trichobothrium (present on other tibiae); tarsus 1 with ~25 pseudosegments, distally quite distinct.

Male (variation). Tibia 1 in 14 other males: 2.6–3.6 (mean 3.0).

Female. In general similar to male ( Fig. 149 ) but cheliceral fangs unmodified. Tibia 1 in 23 females: 2.1–2.8 (mean 2.4). Epigynum anterior plate rectangular with distinctive pair of posterior processes ( Figs 171 , 190 ), shallow pockets (rather sclerotized furrows) in front of anterior plate ( Fig. 166 ); posterior plate short and simple, weakly sclerotized. Internal genitalia with pair of round pore plates close together ( Figs 166 , 172 ).

Distribution. Known from two neighboring localities in Amapá, Brazil ( Fig. 346 ).

Natural history. This species was found in small holes in the ground under the leaf litter. It built tiny webs and ran away quickly when disturbed. At the type locality it was highly abundant: in one case, about 20 specimens were counted within 0.5 m 2. One egg-sac contained 10 eggs.

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

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 189–197. Chibchea amapa sp. n. (189–190, ZFMK, Ar 20627), C. santosi sp. n. (191, ZFMK, Ar 20628), and Arenita fazendinha sp. n. (192–197, ZFMK, Ar 20631). 189. Female palpal tibia; note presence of two trichobothria. 190. Epigynum, ventral view. 191. Female ALS. 192. Female prosoma. 193–194. Male and female ALS. 195. Male gonopore. 193. Female palpal tibia; note presence of only one trichobothrium. 197. Female palpal tarsal organ. Scale lines: 2 µm (193-194, 197), 10 µm (189, 191, 195–196), 100 µm (190, 192).