Cybaeina Chamberlin and Ivie
Creators: name: Bennett, Robb
name: Copley, Claudia
name: Copley, Darren
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Cybaeidae
Cybaeina

description: Genus Cybaeina Chamberlin and Ivie
Cybaeus (in part) Banks 1906: 95.
Cybaeina Chamberlin & Ivie 1932: 28, figs 5–14, 28–30; Chamberlin & Ivie 1942: 19, fig. 38; Roth 1952 (in part): 195, figs 1, 3, 6; Roewer 1954: 86 (in part); Bonnet 1956 (in part): 1296; Roth & Brame 1972 (in part): 16, figs 21–22; Roth & Brown 1986 (in part): 2; Bennett 2005: 88, figs 22.19–22.21, 22.24–22.25, 22.27–22.34; Bennett 2017: 99, figs 23.19–23.21, 23.24–23.25, 23.27–23.34; World Spider Catalog 2023 (in part).
Type species. Cybaeus minutus Banks 1906 by original designation (Chamberlin and Ivie 1932).
Etymology. The genus name Cybaeina is derived from Cybaeus L. Koch and is feminine in gender.
Diagnosis. The males and females of the Nearctic genera of Cybaeinae are readily separated into two groups on the basis of tibia I and II ventral macrosetal characters: members of Cybaeina Chamberlin and Ivie, Neocybaeina Bennett gen. nov., Rothaeina Bennett gen. nov., and Cybaeota Chamberlin & Ivie have four or five pairs of conspicuous elongate, often overlapping macrosetae (Fig. 2) versus Allocybaeina Bennett, Cybaeozyga Chamberlin & Ivie, Cybaeus L. Koch, and Pseudocybaeota Bennett which have only two or three pairs of shorter and nonoverlapping macrosetae (as in Copley et al. 2009: fig. 14; Bennett 2017: fig. 23.14).
Both sexes of Cybaeota can be separated from those of Cybaeina, Neocybaeina gen. nov. and Rothaeina gen. nov. by the absence of a retrolateral patellar apophysis and associated peg setae on the male pedipalp and the relatively simple vulva dominated by very large, rounded spermathecal bases (Bennett 1988: figs 25, 28, 35, 38). In Cybaeina, Neocybaeina gen. nov., and Rothaeina gen. nov., a retrolateral patellar apophysis and associated peg setae are present (Figs 9, 18, 33, 59, 64) and the vulva is relatively complex with the spermathecal bases undifferentiated from the spermathecal heads and stalks (Figs 20, 67, 77) or the bases are relatively small, less rounded, and not dominating the vulva (Figs 23, 42).
Females of Cybaeina, Neocybaeina gen. nov., and Rothaeina gen. nov. are readily distinguished by vulval morphology. In females of Cybaeina, the copulatory ducts are elongate, lightly sclerotized, and encircle the spermathecal stalks (Figs 20–21, 23–24, 26–27). In Neocybaeina gen. nov. and Rothaeina gen. nov., the copulatory ducts are very short, heavily sclerotized, and do not encircle the stalks (Figs 39, 41, 68–69, 73–74, 76, 78).
The males of these three genera, however, are not easily diagnosed; separation of them requires careful referral to a combination of characters of the pedipalp and comparison with published illustrations. In addition, the male of only one of the two species of Neocybaeina gen. nov., N. xantha (Chamberlin & Ivie) comb. nov., is known; the unknown male of N. burnetti spec. nov. may not fit the genus diagnoses presented in this paper. The following characteristics may be helpful in distinguishing the males of these three genera. In the males of all three, the patellar apophysis is quite short (Figs 11, 13) to approximately as long as the width of the patella (Figs 31–34, 53, 62). When elongate, however, the tip of the patellar apophysis is retrolaterad in Cybaeina (Fig. 9) versus dorsad or distad in Neocybaeina xantha comb. nov. (Figs 31, 33) and Rothaeina gen. nov. (Figs 53, 57, 59). As well, in males of Cybaeina, the medial component of the retrolateral tibial apophysis is blade- or ledge-like and distally acuminate (Figs 10–12, 14–17) or terminating in a single elongate basally articulated macroseta (Figs 8–9) whereas in males of Neocybaeina xantha comb. nov. and most species of Rothaeina gen. nov. the medial component is reduced to a single rigid spine-like process or basally articulated macroseta (Figs 31–35, 53, 56–59, 61) or, in R. mackinleyi spec. nov., is a simple elongate ledge not terminating anteriorly in such a process or macroseta (Fig. 54).
Description. As for Cybaeus (see Copley et al. 2009) and in genus diagnosis in this paper.Additional descriptive characters presented here. Small- to medium-sized spiders, carapace lengths averaging 1.80–2.23 mm (males) and 1.85–2.02 mm (females); females usually slightly smaller than males. Eight eyes (Fig. 1) similar to Cybaeus (Copley et al. 2009); anterior median eyes smallest, about 1/2 diameter of anterior lateral eyes. Legs pale yellow to light reddish brown, unmarked. Four (C. confusa) or five complete pairs of ventral tibia I macrosetae; pattern usually 2(+1p)-2-1p-2-2-2-0 or 2(+1p)-2-1p-2-2-0. Abdomen pale to light gray without markings. Colulus a low swelling marked by two clumps of very few setae.
Male: Patellar apophysis (Figs 8–14) with two to nine peg setae. Distal component of retrolateral tibial apophysis (Figs 8, 10, 12, 14, 16) nearly as long as pedipalpal tibia, usually slightly extended distally. Genital bulb with very long, thin, simple embolus (Figs 3–7); distal arm of tegular apophysis well developed with narrow (Fig. 6), tapering (Fig. 5), or slightly expanded tip (Figs 3–4); proximal arm well developed but simple: elongate, slightly twisted with acuminate tip (Figs 3–7).
Female: Epigyne (Figs 19, 22, 25) simple with single, transverse atrium medially or postero-medially. Vulva (Figs 20–21, 23–24, 26–27) with long, slender, weakly sclerotized copulatory ducts, broadly or narrowly contiguous at atrium, looped around spermathecal stalks once to up to 2.5 times; spermathecal heads at anterior margin of vulva; spermathecal stalks relatively elongate, convoluted, narrow; spermathecal bases small, rounded or undifferentiated from stalks; fertilization ducts exit bases posteriorly; Bennett’s glands hidden by copulatory ducts or conspicuous.
Composition and distribution. (Fig. 28). Cybaeina is endemic to coastal western North America from Haida Gwaii and the adjacent mainland islands of British Columbia, Canada to Washington and Oregon, United States of America. We recognize three species: Cybaeina confusa, C. dixoni spec. nov., and C. minuta. All are rarely encountered; C. dixoni spec. nov. is known only from southwestern Curry County, Oregon; C. confusa and C. minuta are relatively widespread with records from west coastal North America from British Columbia south to Oregon (C. confusa has not been recorded in Washington).
Key to the species of Cybaeina
1. Four pairs of elongate, overlapping ventral tibia I macrosetae. Patellar apophysis about 1/2 width of patella with three or four peg setae (Figs 8–9); medial component of retrolateral tibial apophysis distally terminated with single basally articulated macroseta (Figs 8–9); distal arm of tegular apophysis dorsad, tip slightly expanded (Figs 3–4). Spermathecal bases undifferentiated, indistinguishable from spermathecal stalks (Figs 20–21); Bennett’s glands hidden within coils of vulval ducts........................................................................................... confusa Chamberlin & Ivie
- Usually five pairs of elongate, overlapping ventral tibia I macrosetae (as in Bennett 2017: fig. 23.13). Other characters not as above............................................................................................... 2
2(1). Patellar apophysis short, dorsoventrally broad with about nine peg setae (Figs 10–11, 14); medial component of retrolateral tibial apophysis a distinct angular, distally acuminate ledge (Figs 10–11, 14–15). Copulatory ducts make one complete loop around spermathecal stalks (Figs 26–27); Bennett’s glands prominent in dorsal view (Fig. 27)..... dixoni Bennett spec. nov.
- Patellar apophysis small, with two peg setae (Figs 12–13); medial component of retrolateral tibial apophysis inconspicuous except for an elongate acuminate process distally (Figs 12, 16–17). Copulatory ducts make about 2.5 loops around spermathecal stalks (Figs 23–24); Bennett’s glands inconspicuous............................................... minuta (Banks)
description: Published as part of Bennett, Robb, Copley, Claudia & Copley, Darren, 2023, Revision of the western Nearctic spider genus Cybaeina including the description of Neocybaeina gen. nov. and Rothaeina gen. nov. (Araneae: Cybaeidae: Cybaeinae), pp. 97-129 in Zootaxa 5318 (1) on pages 98-100, DOI: 10.11646/zootaxa.5318.1.5, http://zenodo.org/record/8158357