Stethorrhagus tremarctos, Xavier & Brescovit & Bonaldo, 2025

Xavier, Cláudia, Brescovit, Antonio D. & Bonaldo, Alexandre B., 2025, Revising the revision: on 12 new species of Stethorrhagus Simon, 1896 from Colombia and Ecuador (Araneae: Corinnidae: Corinninae), with reassessments of all previously described species, European Journal of Taxonomy 1013, pp. 1-76 : 22-26

Stethorrhagus tremarctos sp. nov.

urn:lsid:zoobank.org:act:

Figs 12–14, 51

Diagnosis

Males of S. tremarctos sp. nov. resemble those of S. mandrillus sp. nov. by the glabrous dVL and AS large, laminar and shifted dorsally ( Figs 13A–C, 14A–B, 16A–C, 17A–B). They can be readily distinguished by the AS triangular in retrolateral view, by the embolus inserted between SePP and SeRP, and by the VTA not bulging ( Figs 13A–C, 14A–B) ( AS diamond-shaped in retrolateral view, SeRP absent, and VTA bulging in S. mandrillus – Figs 16A–C, 17A–B). Females resemble those of S. mandrillus , S. chalybeius , S. maculatus and S. loxodonta sp. nov. by the presence of a circular CO disposed posteriorly in relation to SI ( Figs 13D–E, 16D–E, 46C), differing from S. mandrillus and S. chalybeius by the anterior margin of CO not delimited by a protruding lip (lip present in S. mandrillus , Fig. 9D, and S. chalybeius – Bonaldo & Brescovit 1994: fig. 16d) and from those of S. maculatus and S. loxodonta by the deep, large quadrangular depression anterior to CO ( Figs 13D, 14C) (shallow, subtriangular depression in S. maculatus and S. loxodonta – Figs 19D, 46C).

Etymology

The specific name is a noun in apposition in reference to the monotypic genus Tremarctos Gervais, 1855 , represented by the spectacled bear from South America, since the general conformation of the epigynum (as in Fig. 8D) resembles a bear head in frontal view.

Material examined

Holotype

ECUADOR • ♂; Napo, Yanayacu, Cantón Quijos ; 00°35′57.8″ S, 77°53′25.3″ W; elev. 2132 m; 23–30 Nov. 2009; A.B. Bonaldo leg.; QCAZI 280513 .

Paratypes

ECUADOR • 1 ♀; same data as for holotype; QCAZI 280514 • 1 ♀; same data as for holotype; MPEG 40000 .

Description

Male ( holotype – QCAZI 280513)

COLORATION. Cephalothorax red-brown. Legs orange. Abdomen dorsally gray with orange muscular impressions, light gray ventrally ( Fig. 12A). Sternum with deep sternal excavations ( Fig. 12C).

MEASUREMENTS. Total length 6.76. Carapace 3.42 long, 2.66 wide. Clypeus 0.23. Leg measurements: I: femur 3.00/ patella 1.24/ tibia 2.70/ metatarsus 2.45/ tarsus 1.49/ total 10.88; II: 2.95/ 1.12/ 2.38/ 2.10/ 1.47/ 10.02; III: 2.00/ 1.05/ 1.88/ 2.13/ 1.08/ 8.14; IV: 2.81/ 1.15/ 2.58/ 3.07/ 1.32/ 10.93. Eye diameters: AME 0.23, ALE 0.21, PME 0.18, PLE 0.21. Chelicerae 1.67 long, with three promarginal teeth and five retromarginal denticles.

LEG SPINATION. I – femur d1-1-0, p0-0-1, r0; tibia d0, p0, r0, v2-2-2; metatarsus d0, p0, r0, v2-2-0. II – femur d1-1-0, p0-0-1, r0; tibia d0, p0, r0, v1r-1r-0; metatarsus d0, p0, r0, v2-2-0. III – femur d1-1-1, p0-1-1, r0-0-1; tibia d0, p1-1-0, r1-1-0, v2-2-2; metatarsus d0, p0-1-0, r0-1-0, v2-2-1. IV – femur d1-1-0, p0-0-1, r0; tibia d0, p1-1-0, r1-1-0, v1p-2-2; metatarsus d0, p1-1-1, r1-1-1, v2-2-12.

PALP. Retrolateral surface of femur and patella with a cluster of modified hairs, vVL with three modified hairs on the apex, dVL glabrous and not protuding, AS triangular in retrolateral view and shifted dorsally, DL reduced, spermophor situated prolaterally, TP1 short and pointed, situated medially on tegulum, embolus short and slightly curved in retrolateral view, VTA longer than broad in ventral view ( Figs 13A– C, 14A–B).

Female ( paratype – MPEG 40000)

COLORATION. As in male, except pedipalps orange-brown ( Fig. 12B). Sternum with excavations as in male ( Fig. 12D).

MEASUREMENTS. Total length 7.90. Carapace 3.18 long, 2.65 wide. Clypeus 0.28. Eye diameters: AME 0.22, ALE 0.19, PME 0.21, PLE 0.19. Chelicerae 1.56 long, with three promarginal teeth and five retromarginal denticles. Leg measurements: I: femur 2.94/ patella 1.26/ tibia 2.49/ metatarsus 2.30/ tarsus 1.39/ total 10.38; II: 2.83/ 1.27/ 2.28/ 2.12/ 1.34/ 9.84; III: 2.39/ 1.13/ 1.88/ 2/ 1.15/ 8.55; IV: 3.06/ 1.19/ 2.53/ 3.02/ 1.22/ 11.02.

LEG SPINATION. I – femur d1-1-0, p0-0-1, r0; tibia d0, p0, r0, v2-2-2; metatarsus d0, p0, r0, v2-2-0. II – femur d1-1-0, p0-0-1, r0; tibia d0, p0, r, v1r-1r-2; metatarsus d0, p0, r0, v2-2-0. III – femur d1-1-1, p0-1- 1, r0; tibia d0, p1-1-0, r1-1-0, v2-2-2; metatarsus d0, p0-1-1, r0-1-1, v2-2-1. IV – femur d1-1-1, p0-0-1, r0-0-1; tibia d0, p1-1-0, r1-1-0, v1p-2-2; metatarsus d0, p1-1-1, r1-1-1, v2-2-1.

EPIGYNUM. Copulatory opening circular, posteriorly situated in relation to spermathecae, anterior margin not delimited and depressed, depression anterior to CO deep, triangular, VEP present, PVP covering up to the first half of SI, secondary spermathecae elongated ( Figs 13D–E, 14C–D).

Distribution

Known only from the type locality ( Fig. 51).