Harpactea sadistica, Ŕezáč, 2008

Ŕezáč, Milan, 2008, Description of Harpactea sadistica n. sp. (Araneae: Dysderidae) - a haplogyne spider with reduced female genitalia, Zootaxa 1698 (1), pp. 65-68 : 65-68

Harpactea sadistica n. sp.

Figs 1 –3

Type material. Holotype. 1♂, Israel: Judean foothills: Adulam Nature Reserve, village Nehusha near Jerusalem, Israeli

mapping grid 144/116 (March 22 2002, pitfall trap, Y. Mandelik leg., coll. Hebrew University of Jerusalem).

Paratypes. Same location (1♂ January 18 2002, 1♂ March 22 2002, Y. Mandelik leg., coll. Hebrew University of

Jerusalem; 10♂ April 2003, U. Columbus & T. Levanony leg., coll. University of Haifa; 7♂ 4♀ March 3–7 2004, Y. Lubin et al. leg .; 1♀ April 4 2004, 20♂ 24♀ March 13 & 18 2007, M. Ṙ ezá č, S. Henriquez & S. Pekár leg.; coll. Crop Research

Institute in Prague).

Etymology. The species name refers to the mode of copulation in which the males injure the females to promote paternity success (Ṙ ezá č, unpubl. data). It is an adjective derived from the word sadismus, which means sexual delight while inducing pain to another person. It is derived from the name of the French aristocrat and philosopher Donatien Alphonse François de Sade.

Diagnosis. Harpactea sadistica n. sp. differs from the vast majority of Harpactea species in the male bulbus, which is composed of a single sclerite and possesses a relatively large tegulum and transverse embolus, and in the atrophied female vulva. Furthermore, H. sadistica is differentiated from Harpactea zoiai Gasparo, 1999 and Stalagtia kratochvili Brignoli, 1976 by a lobate conductor and needle-shaped tip of the embolus, from Stalagtia argus Brignoli, 1976 by the presence of the conductor, from Stalagtia thaleriana Chatzaki & Arnedo, 2006 by transverse embolus, and from the remaining Stalagtia species by a bulbus composed of a single sclerite that is equipped with a lobate conductor.

Description. Male. (Holotype). Carapace pale yellow-brown, smooth, 1.7 mm long. Cephalic part narrower than the thoracic part, maximum carapace width 1.26 mm, minimum carapace width 0.63 mm. Fovea apparent, covering almost a third of the thoracic part. Anterior median eye diameter 0.10 mm, posterior lateral eye diameter 0.07 mm, posterior median eye diameter 0.08 mm. Eyes very close to each other, the space between anterior median eyes less than half of their diameter. Sternum pale yellow, slightly shiny. Chelicerae pale yellow-brown, basal segment 0.67 mm long (lateral external view), fang 0.37 mm long. Basal segment with setiferous granulations on the dorsal part, which become more dense on lateral sides. Basal part of chelicerae hairless. Groove of chelicerae 0.18 mm long, covered with hairs arranged in two lines. Retromargin with one tooth on the base of the groove and another, slightly larger one, on its middle part. Promargin with two teeth, the proximal one larger than the distal one, both larger than those at the retromargin. Proximalmost tooth of the retromargin located in the interspace of the two at the promargin. Legs pale yellow, both pairs of forelegs are darker than the two hind pairs. Segment lengths are shown in Table 2. Relative leg length: IV>II=I>III. Spination: patella III dorsally 1–2 spines; femur I proapically 1; femur II proapically 1–2; femur III dorsally 7–9; femur IV dorsally proximally 3 and distally 2; coxa III retrodorsally 0–1; coxa IV retrodorsally 1–2. For spination of tibiae III–IV and metatarsi III–IV see Table 1. Opisthosoma cylindrical, whitish, 2.28 mm long. Palpal segment lengths are shown in Table 2. The bulb is composed of a single sclerite ( Fig. 1 ). The proximal part (tegulum) is spherical, smooth, and relatively large; the distal part is composed of a lobate conductor and a short tubuliform curved embolus, transverse with respect to the tegulum. The tip of the embolus resembles the tip of a hypodermic needle.

Female. All somatic characters as described for the male. Vulva very small, atrophied. The rudiment of the spermatheca slightly sclerotised, visible only by dissection of the genital organ, projected from a slightly sclerotised anterior arc. Anterior arc with curved ventral edge and paddle-shaped dorsal base. The rudiment of the posterior diverticle small, spherical. The posterior transversal bar not developed ( Fig. 3 ).

Variation. Prosoma 1.1–1.7 mm (both sexes).

Ecology. Harpactea sadistica n. sp. occurs in woodlands ( Quercus calliprinos , Pinus plantations) and steppe habitats dominated by Asphodellus. I observed no overlapping generations, therefore it probably exhibits an annual lifecycle. Eggs are laid in March and April.

Discussion. Taxonomy of Harpactea is based largely on genital morphology ( Deeleman-Reinhold 1993). In H. sadistica n. sp., the male copulatory organ, particularly the spherical tegulum and transverse embolus with sub-basal conductor, resemble those of Harpactea zoiai and Stalagtia kratochvili . The relatively small vulva with inverted Vshaped spermatheca is present in species of the genus Stalagtia (as catalogued in Platnick 2007). The taxonomic history, in particilar the justification for the placement of the described species’ putative closest relatives into two genera, needs a more detailed explanation. Originally, the genus Stalagtia was created for large cave-dwelling harpacteinae species with reduced eyes and spony forelegs from the western Balkans ( Kratochvíl 1970). Later, two new species from forests in Greece, S. kratochvili and H. argus , were added to this genus, as their genitalia resembled those of cave-dwelling Stalagtia ( Brignoli 1976) . Nevertheless, Deeleman-Reinhold transferred these two species into the genus Harpactea ; S. kratochvili into the species group rubicunda and S. argus into the species group corticalis, subgroup auriga (Deeleman- Reinhold 1993). Gasparo (1999) considered S. kratochvili , S. argus and a new species from Greece, H. zoiai , a mono- phyletic group belonging to Harpactea , species group rubicunda. However, recently, Chatzaki & Arnedo (2006) widened the definition of the genus Stalagtia and again included S. kratochvili , S. argus and a new species from Crete, S. thaleriana . They did not discuss the generic position of H. zoiai and failed to recognize the resemblance of the palpal morphology in S. thaleriana and in the species of Harpactea , species group corticalis, particularly subgroup auriga (e.g., H. oglasana Gasparo, 1992 ), to the palp of S. thaleriana , from which palp morphology in the former species differs only by the relatively shorter conductor. Moreover, the relatively small vulva with inverted V-shaped spermatheca is present not only in species currently included in the genus Stalagtia , but also in H. catholica ( Chatzaki & Arnedo 2006) , some representatives of the group corticalis e.g., H. rucnerorum ; Ṙ ezá č, unpublished data) and in some undescribed Harpactea species from Portugal. The above seems to cast doubt on the monophyly of Stalagtia sensu Chatzaki & Arnedo (2006) .

The male colpulatory organs, which may be viewed as the arms in the fight for paternity ( Arnquist & Danielsson 1999), diverge relatively quickly as new insemination strategies evolve ( Eberhard 1985). For example, the conductor has very different functions in particular Harpactea species : in some species it opens the female epigastric furrow, in others it anchors inside female genitalia, or, in H. sadistica , it hooks the other bulb into position during copulation (Ṙ ezá č, unpublished data). On the other hand, similar strategies in sperm competition are expected to result in morphological convergence. Therefore, the male palpal bulb morphology may be misleading for exploration of phylogenetic relationships. The same may hold for the morphology of the vulva. In some obviously unrelated Harpactea species , particularly H. sadistica n. sp. and a not yet described Portuguese species exhibiting no morphological similarities with H. sadistica n. sp., special insemination modes have been observed, where the sperm is no longer stored in the spermatheca or the posterior diverticle (Ṙ ezá č, unpublished data). Consequently, the vulva is atrophied in these species. Interestingly, the result of its reduction is very similar: a small vulva with inverted V-shaped spermatheca. Such morphological convergences should be taken into consideration in future taxonomic studies.

For elucidation of the phylogenetic structure of the genus Harpactea and allied genera, a comprehensive taxonomic revision of the subfamily Harpacteinae , based on molecular characters, is needed. Until then I propose to follow the narrow definition of the genus Stalagtia presented by Deeleman-Reinhold (1993).

Figures

FIGURES 1–3. Copulatory organs of Harpactea sadistica n. sp. 1 Left male copulatory organ, lateral view. C: conductor, E: embolus, T: tegulum. 2 Left male copulatory organ, medial view. 3, Atrophied female copulatory organ. PD: posterior diverticle, S: spermatheca, TB: transversal bar. Scale bars, 0.1 mm.