Gnaphosidae Pocock 1898, new species

Gnaphosidae Pocock, 1898

Zimiromus Banks, 1914 Zimiromus recs, new species Figs 1–14

Type material. Male holotype (MACN-Ar 28376), two males (MACN-Ar 28374, 28373) and two female paratypes (MACN-Ar 28375) from Argentina: Ciudad Autónoma de Buenos Aires: Reserva Ecológica Costanera Sur. Camino de los sauces: mirador al Canal Sur S34º37’1.75" W58º20’50,28", 4 November 2011, under dead leaves of Cortaderia selloana. C. Grismado & L. Zapata coll. Same locality, 24 October 2011, L. Zapata, G. Rubio, M. Izquierdo, M. Guala and C. Grismado coll., two additional ɗ paratypes (MACN-Ar 28377, 28378, the last together with 7 immatures).

Etymology. The specific name is a noun in apposition derived from the initials of the “Reserva Ecológica Costanera Sur” (RECS)

Diagnosis. The male palp of Z. recs n. sp. resembles those of Z. kochalkai Platnick & Shadab 1976 (from Colombia), Z. montenegro Buckup & Brescovit 1993 (from Brazil) and Z. tropicalis (Banks 1909, from Central America) by the shape of the conductor and the course of the seminal duct (Platnick & Shadab 1976, figs 5–6, 33–34; Buckup & Brescovit 1993, figs 5–6). It is easily distinguished from Z. tropicalis by the lack of the distally expanded embolus, and from the other two species by the widened median apophysis (Figs 7–9, 12–13), and the also widened basal part of the ventral branch of the RTA; it also differs from Z. kochalkai by the embolus with more basal and gradual origin (Figs 7–8, 12) and from Z. montenegro by the different tip of the dorsal branch of the RTA (Figs. 9, 13). Males of Z. recs n sp., unlike the above mentioned species, have enlarged bases of the tibial retrolateral setae (Figs 9, 13), similar to those of Z. medius (Keyserling 1891, Platnick & Shadab 1976, fig. 30). The females of Z. recs also resemble those of Z. kochalkai and Z. montenegro by the general epigynal morphology (Platnick & Shadab 1976, figs. 35–36; Buckup & Brescovit 1993, figs 7–8), but are recognizable by the slightly widened tip of the scape (Figs 10–11, 14), the copulatory and median ducts thinner than those of Z. kochalkai, and the copulatory ducts not describing the strong backward curve found in Z. montenegro.

Description. Male (holotype): Total length 4.58. Carapace 1.89 long, 1.57 wide. Femur II 1.60 long. Eye sizes and interdistances: AME 0.14, ALE 0.11, PME 0.17, PLE 0.13, AME–AME 0.11, AME–ALE 0.04, PME–PME 0.1, PME– PLE 0.05, ALE–PLE 0.04, MOQ long 0.4, MOQ front width 0.32, MOQ back width 0.4. Carapace light brown, abdomen light gray with anterodorsal scutum orange brown (Fig. 1, 2); venter lighter than dorsum. Embolus dark, with basal origin, gradually narrowing, with terminal part hidden in the folded conductor (Figs. 8–9, 12–13); median apophysis widened, ventral lobe of the retrolateral tibial apophysis much shorter than dorsal lobe, with conspicuously enlarged setae bases (Figs. 9, 13). Palpal femur distal ledgelike dilation with serrate margin (Figs. 9, 13). Leg spination: femora: I d1-0-1, p0-0-1; II d1-1, p0-0-1; III d1-0-1-1 (right 1-0-1-0), p0-1-1, r0-0-1; IV d1-1-1 (right 1-1), p0-0-1, r0-0- 1; patellae: III p1, r1; IV r1; tibiae: I v 1 -0-0-1-1-0-1ap; II v1 -0-1-0; III d1-2-0, v1-1 -2ap (right 0-1-2ap), p0-0-1, r0-0-1; IV d0-1-0, v1-1 -2ap, p0-1-1, r1-1; metatarsi: I v2 -0-0; II v2 -0-0; III d2ap, v1-1 -0-1ap (right 1-1-0-0-1ap), p0-1-0-1ap (right 0-1-1-0-2ap), r0-1-0-1ap; IV d0-2-0-2ap, v1-1 -1-2ap, p0-1-1ap, r1-1-1ap (right 0-1-1ap).

Variation (five specimens): Total length 3.77–5.19, carapace length 1.65–2.22, carapace width 1.29–1.72, femora II length 1.29–1.69.

Female (paratype): Total length 4.91. Carapace 2.06 long, 1.64 wide. Femora II long 1.61, AME 0.13, ALE 0.14, PME 0.16, PLE 0.15, AME–AME 0.12, AME–ALE 0.02, PME–PME 0.1, PME–PLE 0.05, ALE–PLE 0.064, MOQ long 0.41, MOQ front width 0.37, MOQ back width 0.41. Colour as in the male (Figs. 3, 4). Internal genitalia (Figs. 11, 14): spermathecae (S) large, ovoid; copulatory ducts (CD) anteriorly bent approximately in right angle towards the base of the spermathecae; in this part arise the thin, slightly curved median ducts (MD) that connect with the posterior, rounded seminal receptacles (SR). Spination: femora: I d1-1, p0-0-1; II d1-1, p0-0-1; III d1-0-1-1, pd0-1-1, rd0-1-1; IV d1-0-1-1, p0-0-1, r0-0-1; patellae: III p1, r1; IV p1, r1; tibiae: I v0-2-1ap; II v1 -0-1-0-1ap, p0-0-1ap; III d1-0-0, v1-1 -0- 2ap, p0-1-1, r0-1-1; IV d0-1-1-0-1 (right 1-0-1), v1-1 -0-2ap, p0-1-0-1, r0-1-0-1; metatarsi: I v2 -0-0; II v2 -0-0; III d0-2- 0-2ap, v0-1-0-1ap, p0-1-0-1ap, r0-1-0-2ap; IV d0-2-0-0-0-2 (right 0-2-2-0-0-2), v1-1 -0-2ap, p1-0-1-0-0-1 (right 0-1-0- 1), r0-1-0-1 (right 1-1-0-1).

Variation (two specimens): Total length 4.40–4.91, carapace length 2.06–2.12, carapace width 1.59–1.64, femora II length 1.61–1.65.

Distribution. Only known from the type locality. Searching in the collection of MACN, we found an additional single female from Misiones Province (PN Iguazú, November 1989, M. Ramírez coll., MACN-Ar 18292) that is very similar to those here described from Buenos Aires. It differs only by having a slightly widened epigynal scape and a more pronounced dorsolateral torsion of the course of the copulatory ducts. Given the large gap between the records (more than 1000 km), and the absence of samples in intermediate regions, we opted in postpone the formal assignment of this female until additional material from Misiones (especially males) will be collected.

Life history and habitat preferences. The specimens were collected sifting the organic litter accumulated under dead leaves of pampas grasses (Cortaderia selloana) shaded by the trees of a forest of Salix humboldtiana, near the margin of a coastal lagoon, permanently communicated with Río de la Plata estuary. The ecosystem is composed by recently developed riparian plant communities, typical of this region.