Nemaspela borkoae sp. nov.

urn:lsid:zoobank.org:act: D4139CAA-5F9A-4766-9FE5-6DABFA7BF26C

Figs 1–5, Table 1

Etymology

The species name borkoae is dedicated in honor of Špela Borko (Ljubljana), enthusiastic speleologist and speleobiologist, who collected the first specimen of this species.

Diagnosis

Small (1.5–2.1) long-legged Nemaspela species of the western Nemaspela group, without male cheliceral apophysis, and with disproportionately long pedipalp trochanter and tarsus. Pedipalp trochanter straight, pedipalp tarsus strongly (♂) bent ventrally. Glans with sparse minute spines gradually tapering into a short, slightly ventrally bent stylus. According to recent knowledge, endemic to the Krivošije karst plateau and Mt. Lovćen, Montenegro.

Material examined

Holotype MONTENEGRO • ♂; Lovćen, Njeguši, Dvogrla jama; 42.43301° N, 18.83159° E; 873 m a.s.l.; 10 Sep. 2014; Špela Borko leg.; the cave section of “Veliki fosilni kanal”, depth: 50–80 m, on wet flowstone, collected by hand; PMSL-Opiliones-PK&TN 4/2019.

Paratypes MONTENEGRO • ♀ allotype; Krivošije, Kameno more, PT4; 42.55183° N, 18.73864° E; approximately 800 m a.s.l.; 3 May 2018; Špela Borko leg.; the cave section of “Moonmilk pitch ”, at an approximate depth of 180 m, on damp vertical rocks coated with moonmilk-like surface, collected by hand; PMSL-Opiliones-PK&TN 7/2019 • 2 ♂♂; same collection data as for preceding; 3 May 2018; Teo Delić leg.; PMSL-Opiliones-PK&TN 2/2019, PMSL-Opiliones-PK&TN 3/2019 • 1 ♀; Grahovo, Dragaljsko polje, Vodna jama; 42.60762° N, 18.68783° E; 615 m a.s.l.; 14 May 2019; Teo Delić leg.; the cave section of “Syphon chamber”, on a vertical wet flowstone wall covered with organic sediment, at an approximate depth of 135 m, collected by hand; PMSL-Opiliones-PK&TN 1/2019 • 1 ♂, 1 juv.; Lovćen, Zverinjačke rupe, Pala skala; 42.36908° N, 18.83575° E; 1328 m a.s.l.; 17 May 2019; Teo Delić leg.; on a wet flowstone meander, at a depth of 370 m, collected by hand; PMSL-Opiliones-PK & TN 8/2019.

Description

Male, holotype

BODY. Body length 1.57, width 0.86, body tender, with scutum magnum. Body color light beige (Fig. 1 AC). Dorsum weakly sclerotized, with dense, short mucronate, cuticular microtubercles (microtrichia) covering most of the cephalothorax and abdomen. Supracheliceral lamellae (Fig. 1D) large, with straight frontolateral margins and mammillary tubercles, similar to those in N. ladae (Karaman 2013; fig. 14). Ocular tubercle low but well pronounced, wider than long, starting about half its length behind anterior edge of dorsal scutum. Cuticle of cephalothorax thicker in center and thinner towards edges, with scattered oval and irregularly shaped spots of thinner parts (Fig. 1E). Eyes completely reduced. Coxae and ventral side of the body with sparse long setae in a transverse row in the middle of each sternite (Fig. 1 B–C).

CHELICERAE. Beige-brown, long and slender (Fig. 2B, F), without apophysis and gland openings. Lengths of basal article, distal article and movable finger, 0.99, 1.19 and 0.37, respectively. Basal segment basally and terminally widened. Distal segment distally enlarged, frontally evenly set with long bristles, the longest ones shorter than the article diameter. Fixed finger with a series of 21, movable finger with 23 diaphanous teeth.

PEDIPALPS. Light beige-brown, without secondary sexual characteristics (Figs 2A, 3A), very long, slender, with scattered, very densely set clavate glandular setae on all articles, except trochanter, diminishing in size from femur to tarsus, and giving a voluminous appearance in live animals. Femur straight, terminally slightly enlarged. Patella slightly shorter than femur, straight, with one long bristle dorso-distally. Tibia distally gradually narrowing. Tarsus long, slightly club-like, at the very proximal portion conspicuously bent ventrally at an angle of ca 45°, with a few long bristles. For article lengths, see Table 1.

LEGS (Fig. 3D, Table 1). Beige with darker article endings, very long and thin (L body: L leg II = 1:15.7), with numerous pseudoarticulations. Claws simple, ventrally bent. Leg articles cylindrical, with dense cover of fine bristles, interspersed by a few long ones (Fig. 3D).

PENIS (Figs 2 C–E, 3B, on Fig. 3C protruding glans). 1.43 long, glans 0.18, basis 0.31. Truncus slightly dorsally bent, distally gradually slightly widened, narrowest near the basis, slightly dorso-ventrally compressed. Basis straight, bulbous, incised for about two-fifths its length. Glans brownish, conical and basally slightly wider than truncus, with sparse minute spines, terminally gradually tapering into a short stylus.

Female

BODY. Body length 2.11, width 1.48, body egg-shaped, with scutum magnum. Color of body light beige (Figs 4 A–B, 5D).

CHELICERAE. As in male, more robust (Fig. 4C). Lengths of basal article, distal article and movable finger 1.01, 1.19 and 0.48, respectively.

PEDIPALPS (Fig. 4D). As in male, for lengths of articles see Table 1.

LEGS (Table 1; Fig. 5D; distal tarsomerae Fig. 5C). As in male, but shorter. Claws as in male.

OVIPOSITOR (Fig. 5A, left: lateral view, right: ventral view). ca 0.62 long, receptacula seminis monovesicular, with tear-like anterior bulge, ca 85 μm (Fig. 5B).

Relationships

Nemaspela borkoae sp. nov. is, besides N. ladae, the second species of Nemaspela in the Balkans. Both belong to the western group of Nemaspela, and are missing the male cheliceral apophysis. The cheliceral apophysis is, except in N. femorecurvata, present in all species of the eastern group of Nemaspela. The two Balkan species can be distinguished by the following ♂ characteristics (♀ of N. ladae unknown at the time; Karaman 2013):

1. Pedipalp trochanter about ¼ femur length, tarsus straight, about ½ tibia length, glans terminally rounded, stylus wide-flattened, tube-like, curved ....................................... N. ladae Karaman, 2013

– Pedipalp trochanter ¼ femur length, tarsus on very proximal portion conspicuously bent ventrally, about ¾ tibia length, glans gradually tapering into a short stylus slightly bent ventrally .................. ............................................................................................................................. N. borkoae sp. nov.

Distribution

Nemaspela borkoae sp. nov. has been found in four caves in Dragaljsko polje, the Krivošije karst plateau and Mt. Lovćen (Fig. 6).

Ecology

All the specimens of N. borkoae sp. nov. were collected in four caves situated in western Montenegro within the maximum linear extent of 30 km, in an area that receives the highest amount of precipitation in Europe (Ducić et al. 2012). The specimens were found at depths from about 50 to 370 m, at temperatures between 4.8 and 7.8°C. They were all found in places close to running water or in places susceptible to water level oscillation. However, three different habitat types can generally be distinguished: i) the vertical wet flowstone covered with organic sediment; ii) wet flowstone meanders subjected to occasional flooding; and iii) cave walls coated with the moonmilk-like surface. Some of the habitats were shared with other specialized subterranean fauna belonging to the following genera: Verhoeffiella Absolon, 1900 (Collembola: Entomobryidae), Neotrechus G. Muller, 1913 (Coleoptera: Carabidae), Abasola Strand, 1915 (Opilinones: Travuniidae). The relatively long appendages in Nemaspela borkoae sp. nov. suggest adaptation to spacious habitats, while their movable, pointed claws enable efficient clinging in slippery and water-drenched sites.