Pastaza roberti, Dupérré & Tapia, 2025

Dupérré, Nadine & Tapia, Elicio, 2025, Revision of the Ecuadorian Microstigmatidae (Araneae: Mygalomorphae), with the description of six new species, European Journal of Taxonomy 1007, pp. 87-132 : 111-118

publication ID	https://doi.org/10.5852/ejt.2025.1007.2999
publication LSID	lsid:zoobank.org:pub:3D9557C2-29EA-46CD-8E4C-40D22DDE4CAF
persistent identifier	https://treatment.plazi.org/id/038487E4-FFD0-FF86-FDE8-FA15FE297DC2
treatment provided by	Plazi
scientific name	Pastaza roberti
status	gen. et sp. nov.

Treatment

Pastaza roberti gen. et sp. nov.

urn:lsid:zoobank.org:act:444A732F-F01C-4A79-B893-5F34B3B82FBF

Figs 15– 20 View Fig View Fig View Fig View Fig View Fig View Fig , 29E View Fig , 30 View Fig

Diagnosis

Males most resemble those of P. vegai sp. nov. but are distinguished by their palpal bulb with two large keels ( Fig. 17D View Fig ), one keel in the latter ( Fig. 23D View Fig ). Females most resemble those of P. aureliae sp. nov. but are distinguished by the internal genitalia with spermathecae separated by 2× their diameter, and on elongated stalks ( Fig. 20C–E View Fig ) whereas in the latter, spermathecae are closer together, separated by their diameter and on short stalks ( Fig. 14C–E View Fig ).

Etymology

The specific epithet is a patronym in honor of Robert Raven, for his contribution to the study of mygalomorph spiders and his support in the study of the South American fauna.

Type material

Holotype

ECUADOR • ♂; Sucumbíos, Green Paradise Lodge ; 0°22′47″ S, 76°09′10″ W; 231 m a.s.l.; 24 –28 July 2023; M. Huben and J. McClarin leg.; trap, yellow pan; ECFN 11674; QCAZ. GoogleMaps

Paratypes

ECUADOR • 2 ♀♀; Sucumbíos Province; Limoncocha ; 0°23′10″ S, 76°36′41″ W; 264 m a.s.l., 21 July 2024; E. Tapia, A. Tapia and N. Dupérré leg.; night collecting along trail; ECFN 11664; ZMH-A0030714; ZMH GoogleMaps • 1 ♀; Napo Province; Parroqui Ahuano, Ahuano, Via Misahualli-Ahuano , sector Jatun Sacha , poblado Ñucanchi Causai ; 1°03′52″ S, 77°36′42″ W; 387 m a.s.l.; 27 Dec. 2022; E. Tapia and I. Tapia leg.; in burrow at the base of a tree, burrow with lid, at the end of dry season; ECFN 9369; QCAZ GoogleMaps • 1 ♀; same data as for preceding; ECFN 9370; DTC GoogleMaps .

Description

Male (holotype)

MEASUREMENTS. Total length: 12.01; carapace length: 6.16; carapace width: 4.82; abdomen length: 5.85.

CEPHALOTHORAX. Carapace elongated-oval, dark orange-brown slightly darker along radiating lines and margin; pars cephalica flat, pars thoracica sloping; fovea slightly recurved ( Fig. 16A View Fig ).

CHELICERAE. Dark reddish-brown, rastellum absent; with 12 promaginal teeth, 15 intermarginal denticles; intercheliceral tumescence inconspicuous. Labium orange margin V-shaped with four cuspules ( Fig. 16B View Fig ). Maxillae orange, anterior lobe small; with 17 cuspules ( Fig. 16B View Fig ); serrula present. Sternum longer than wide (2.21 length, 2.13 width); with three rounded to oval, marginal sigilla ( Fig. 16B View Fig ). Eight eyes in two rows; AME 0.26, ALE 0.30, PME 0.1, PLE 0.19, PME–PME 0.56; ocular quadrangle rectangular (1.03 anterior, 1.01 posterior, 0.51 high).

LEGS. Uniformly dark orange-brown ( Fig. 15A View Fig ); scopula on tarsi I–II completely divided, metatarsi I–II 25% apical; tarsi III completely divided, metatarsi III absent, tarsi IV absent (just a few setae), metatarsi IV absent; tibia I with clasping spur ( Fig. 16C View Fig ); filiform trichobothria on all tarsi; tarsi with STC with 5–8 teeth, ITC present on all legs; tarsal organ highly elevated (observed under light microscope). Leg measurements: I 20.18 (5.39/2.88/5.07/3.72/3.12); II 18.28 (4.68/1.90/4.48/4.47/2.75); III 17.20 (4.49/2.14/3.56/4.50/2.51); IV 24.96 (6.22/2.36/5.89/7.50/2.99); leg formula 4123. Leg spination (spines on all segments except tarsi): I fe d1-2-1-1-2, pa p1, v2(apical), ti p1-1, r1-1-1, v2-2-2(apical + 1 clasping spur), mt v1-1-2(apical), p1; II fe d1-2-1-1-2, pa p2, v2(apical), ti r1-1, p1-1, v2-2-3, mt p1-1, v2-2- 2(apical); III fe d2-3-2, pa p1, r1-1, v1, ti d2-1-1, p1-1, r1-1, v2-2-3(apical); IV fe d1-1-2-3, pa p1, r1, v1, ti d1-1-1, r1-1-1, p1-1, v2-2-3(apical), mt d1-1-1, p1-1, r1-1, v2-1-2-3(apical).

ABDOMEN. Oval, dorsally dark grayish-brown with yellowish markings, with thick setae anteriorly on sclerotized socket ( Fig. 15A View Fig ); ventrally light yellow with dark gray meshy pattern basally; spinnerets short (PMS 0.48\PLS 1.05).

GENITALIA. Palpal tibia (2.57 length, 1.13 width); cymbium without spines ( Fig. 17A–B View Fig ); bulb with acutely pointed tegular heel ( Fig. 17C View Fig ), strongly constricted; base of embolus with two major keels, embolus twisted with wide tip ( Fig. 17C–E View Fig ).

Female (paratype ECFN 9369)

MEASUREMENTS. Total length: 13.31; carapace length: 6.58; carapace width: 5.65; abdomen length: 6.73. Live coloration. Carapace dark blackish-brown with reddish-brown marks on pars thoracica, chelicerae black, abdomen dark brown-orange covered with black setae; leg blackish-brown, tarsi dark brown-orange ( Fig. 18A View Fig ).

CEPHALOTHORAX. Carapace as in male, except fovea straight ( Fig. 20A View Fig ). Labium dark orange-brown, margin V-shaped; with seven cuspules ( Fig. 20B View Fig ). Maxillae orange, with small anterior lobe; with 18 cuspules ( Fig. 20B View Fig ); serrula present. Sternum wider than long (2.68 length, 3.02 width); with three marginal, oval sigilla ( Fig. 20B View Fig ). Eight eyes in two rows: AME 0.22, ALE 0.35, PME 0.12, PLE 0.35, PME–PME 0.66; ocular quadrangle rectangular (1.25 anterior, 1.25 posterior, 0.66 high).

CHELICERAE. As in male; rastellum absent; with 12 promarginal teeth and 20 intermarginal denticles.

LEGS. Uniformly dark orange-brown; scopula absent; filiform trichobothria on all tarsi; tarsi with STC with 3–5 teeth per row, ITC on all legs; tarsal organ highly elevated ( Fig. 29E View Fig ). Leg measurements: I 16.02 (4.47/2.66/3.89/3.22/1.78); II 15.84 (4.39/2.64/3.72/3.30/1.79); III 15.21 (3.88/2.26/3.08/3.83/2.16); IV 21.84 (5.39/2.39/5.33/5.87/2.86); 4123. Leg spination (spines on all segments except tarsi): I fe d1-1-1, pa 0, tib v2-2-3(apical), mt v2-2-2(apical); II fe d1-1-1, pa 0, tib v2-2-3(apical), mt v2-2-2(apical), p1; III fe d1-1, pa p1-1, ti d1-1, p1-1, r1-1, v2-2-3(apical); IV fe d1-1-1, pa r1, ti p1-1, r1-1, v2-2-3(apical), mt d1-1-1, p1-1-1-1, r1-1-1, v2-1-2-3(apical).

ABDOMEN. Oval, dark grayish-brown with yellowish markings, with thick setae on sclerotized sockets anteriorly ( Fig. 19A View Fig ); spinnerets short (PMS 0.67\ PLS 1.29).

GENITALIA. Internal genitalia, spermathecal bases wide, with large mushroom-shaped spermathecal heads on long stalks, separated by 2 × their diameter ( Fig. 20C–E View Fig ).

Natural history

The male was collected in a pitfall trap, while females were hand collected in their burrow with lid ( Fig. 18B View Fig ). The species was found between 231–387 m a.s.l. in the lowland evergreen forest of the Amazonian region (BsTa02) ( Guevara et al. 2013b).

Distribution

Sucumbíos and Napo provinces.

Remarks

Male and females were not collected together, the match is made on habitat compatibility and morphological similarity.