Cybaeozyga furtiva, Hedin & Ramírez & Monjaraz-Ruedas, 2025

Hedin, Marshal, Ramírez, Martín J. & Monjaraz-Ruedas, Rodrigo, 2025, Phylogenomics of North American cybaeid spiders (Araneae, Cybaeidae), including the description of new taxa from the Klamath Mountains Geomorphic Province, ZooKeys 1226, pp. 47-75 : 47-75

Cybaeozyga furtiva sp. nov.

Figs 8 , 9 , 10

Material examined.

Holotype: – California, Del Norte Co. • ♀; E Crescent City , 41.8, - 124.0 (GPS, ± 10 km); elev. 150 m, 25–29 Jun. 2017; wet mixed forest with redwood; coll. M. Ramírez & P. Michalik; SDSU_TAC 000889 ; Paratypes: same data as holotype; • 2 ♀; SDSU_TAC 000890 ; • 3 ♀; MACN -Ar 46970 ; • 2 ♀; MACN -Ar 38631 .

Additional material.

– California, Del Norte Co. • 9 ♀ (together with several immatures); same data as holotype; MACN -Ar 38888 ; • 1 ♀; same data as holotype; MACN -Ar 38862 ; sample MJR-2128 ; • 1 ♀; same data as holotype; MACN -Ar 38880 ; samples MJR-1985 , 1986, 1987, 1989; photos 7932–7934 ; • 1 ♀; same data as holotype; MACN -Ar 38948 ; sample MJR-2036 attachment disks ; • 1 ♀; same data as holotype; MACN -Ar 38936 ; samples MJR-1985 , 1987, photos 7915–7930 ; • 1 ♀; same data as holotype; MACN -Ar 38958 ; sample MJR-2130 ; • 2 ♀ (together with 1 immature); same data as holotype; MACN -Ar 38386 ; • 1 ♀, several immatures; southeast of Hiouchi, along South Fork Smith River , 41.76, - 124.01 ( GPS, ± 10 km); 24 Jul. 2024; N-facing rockpile, mixed redwood forest; coll. M. Hedin & O. Hedin ; – California, Humboldt Co. • 1 ♀; nr. Tish Tang Campground , SE of Hoopa; 41.01914, - 123.63594; elev. 120 m; 26 Jun. 2017; mixed broadleaf forest; coll. M. Ramírez & P. Michalik; MACN -Ar 38673 .

Etymology.

furtiva (L., hidden, concealed), from the rarity, and microhabitat preference, of this species.

Diagnosis.

The epigynum of C. furtiva sp. nov. differs from that of C. heterops Chamberlin & Ivie (1937) in possessing a slightly more sclerotized and rugous epigynal plate anterior to the epigastric furrow, with white (glandular?) material lying anterior to the spermathecae, and longer spermathecae that nearly meet at the midline.

Description of ♀ holotype.

( SDSU _TAC 000889 ; Figs 8 B – H , 9 A, J – M ). Color in alcohol greenish brown with dark gray dorsal pattern. Carapace with dark markings extending from eyes to cephalic area, and sides of cephalic area; abdomen grayish with dark pattern dorsally, laterally and around spinnerets. Sternum unmarked. Legs darker at distal femora, basal tibiae, and basal metatarsi. Cheliceral promargin with three teeth (two basal together, one distal parted), retromargin with seven very small teeth.

Total length 3.53, carapace length 1.40, carapace width 1.05, cephalic region width 0.60, posterior eye row width 0.45. Anterior median eyes missing, represented by small dark blotches of black pigment. Eye diameters ALE: PLE: PME = 0.09: 0.08: 0.08. Sternum length 0.70, sternum width 0.67. Leg formula 1423. Leg I article lengths (1.27, 0.49, 1.08, 1.05, 0.75 = 4.64) leg IV article lengths (1.37, 0.45, 1.25, 2.67, 0.90 = 6.64). Abdomen 2.17 long.

Leg macrosetae (Fig. 9 C – I , paratype MACN -Ar 46970 ) absent on femora, 1-1 on patellae (dorsal), thick on legs I – III, weaker on IV. Tibia I ventral 2-2 - 0, prolateral 1-1 - 0, dorsal 1-0 weaker; metatarsus I prolateral 1-1 - 1 - 1, ventral 2-2 - 2 - 0 not well paired. Tibia IV prolateral 1-1, ventral 1-1, retrolateral 0-1, dorsal 1-0 - 1; metatarsus IV prolateral 1-1, ventral 0-1 - 1, retrolateral 0-0 - 2. Patellae with basal fracture region seen as darker indentations at the sides (Fig. 9 A, B ).

Spinnerets short, colulus a hairy patch (Fig. 9 J ). Epigynal plate oval with sinuous transversal ridge and rugous median area (Fig. 9 K, L ). Wide proximal copulatory ducts filled with whitish material (Fig. 9 K ), spermathecae posterior, transversal. Copulatory openings not seen, probably in the anterior ridges and leading to the wide, soft copulatory ducts and from there to posterior spermathecae. Bennett’s gland large, on ectal side of spermatheca (Fig. 9 M ), fertilization ducts posteriorly placed.

Variation.

The black pigment replacing the missing anterior eyes is variable in location between and below the ALEs, and often asymmetrical (Fig. 8 H ). Epigyna from the two geographically distant locations (Fig. 10 ) are very similar in detail.

Distribution and natural history.

Confirmed specimens from Del Norte and Humboldt counties, California (Fig. 10 ), at lower elevations (120–150 m). Topotypic specimens were abundantly collected under rock piles or logs, and in leaf litter, in wet mixed conifer forest. Males were only represented as penultimates. Robb Bennett (pers. comm.) has examined female specimens from Siskiyou County (southeast of Seiad Valley, Fig. 10 ), currently housed in the American Museum of Natural History, that appear to match this species.

Comments.

This new species adds to the described species diversity of Cybaeozyga , a notoriously poorly known genus. Chamberlin and Ivie (1937) described Cybaeozyga and the then only known species ( C. heterops ) from a single male specimen, citing the type locality as “ Grave Creek, Oregon (near Klamath Falls). ” The authors did not include county information in their locality data. Later, Roth and Brame (1972) provided illustrations for a male C. heterops , matching the holotype description, and the previously undescribed female, presumably from the same location. Although precise locality data were not provided in this publication, we have seen specimens of Cybaeozyga from Grave Creek, Josephine County, OR collected by Roth (M. Hedin, pers. obs.). Our female specimens of C. heterops match closely the epigynal drawings of Roth and Brame (1972: fig. 25), and originate from Grave Creek, near confluence with Butte Creek, ~ 50 km NNW of Grants Pass, Josephine County, OR (Suppl. material 1). We view this as near the probable type locality for this species (Fig. 10 ); this location is approximately 200 km NW of Klamath Falls, Oregon.

Additional known, but still undescribed species of Cybaeozyga have been mentioned in the literature. Roth and Brame (1972) note three undescribed species from caves in northwestern California (see also Bennett et al. 2017). Overall, the distribution of Cybaeozyga appears to include forests and caves of the Klamath Mountains ecoregion of northwestern California and southwestern Oregon (Fig. 10 ).

Figures

Figure 8. Cybaeozyga furtiva sp. nov. ♀ (A MACN - Ar 38880, B – H holotype) A live specimen MACN - Ar 38880 B dorsal view C ventral view D prosoma dorsal view E prosoma lateral view F prosoma anterior view G eyes dorsal view H eyes anterior view.

Figure 9. Cybaeozyga furtiva sp. nov. ♀ (A, J – M holotype B – I paratype MACN - Ar 46970) A patellae and tibiae I, arrows to fracture lines B patellae III – IV fractured, arrows to fracture lines C left leg I, prolateral view D same, retrolateral view E tarsus I prolateral view F tarsus IV prolateral view G tibia I ventral view H metatarsus I ventral view I left leg IV prolateral view J spinnerets ventral view K epigyne ventral view L cleared epigyne ventral view M cleared epigyne dorsal view. Abbreviations: BG = Bennett’s gland, FD = fertilization duct, PCD = proximal copulatory duct, S = spermatheca.

Figure 10. Species distributions of Siskiyu armilla sp. nov. and Cybaeozyga, including C. furtiva sp. nov. and C. heterops. Locations approximate, see text and Suppl. material 1 for precise location data.