Plutomurus eristoi, Barjadze, Shalva, Baquero, Enrique, Soto-Adames, Felipe N., Giordano, Rosanna & Jordana, Rafael, 2016

Barjadze, Shalva, Baquero, Enrique, Soto-Adames, Felipe N., Giordano, Rosanna & Jordana, Rafael, 2016, New diagnosis for species of Plutomurus Yosii (Collembola, Tomoceridae), with descriptions of two new species from Georgian caves, Zootaxa 4126 (1), pp. 77-96 : 87

Plutomurus eristoi sp. nov.

Figs 25–37

Type locality. GEORGIA, Imereti region, Tskaltubo district, Dzedzileti village, Sataplia-Tskaltubo karst massif, Satevzia Cave, 42°25'52.01"N, 42°33'58.12"E, 273 m. alt.

Type material. Holotype: Satevzia Cave (dark zone), 22.iii.2012, female (code: CAU SATEVZIA 20120322 01). Paratypes (same data as Holotype): five specimens in slide [ CAU SATEVZIA 20120322 0 2 to 06]; one specimen mounted on SEM stub [ CAU SATEVZIA 20120322 07]. Deposited material: holotype and paratype 2 in MZNA; other paratypes in ISU.

This new species was previously mentioned from Satevzia Cave as “ Plutomurus sp. 7” (Barjadze et al. 2015).

Description. Body length up to 3.15 mm excluding antennae (holotype 2.9 mm) (mean 2.9 mm, n = 4). Body cuticular, colour brownish-grey, with patches of darker pigmentation over the whole body except on antennae, legs (trochanter to tibiotarsus) and dens. Scales cover antennal I and II segments, head, body and legs.

Head. Eye patch small, eyes not seen with light microscopy; Ratio body length/antennae length 1.14 (n = 3) (holotype 0.98). Prelabral chaetae 3 + 3, labrum with 5, 5, 4 chaetae on tubercles and 4 curved hooks distally ( Fig. 25 ); labial chaetae smooth with labial papillae as in Fig. 26 . Maxillary palp trifurcate, distal papilla chaeta longer than basal chaeta; sublobal plate with four sublobals, all shorter than basal chaeta ( Fig. 27 ).

Body. Third leg with well developed trochanteral and femoral organs, with about 38 and 34 chaetae respectively, a few chaetae outstanding ( Fig. 28 ). Ventral tube with 30–35 distal, 12 + 12 anterior and 80–100 posterior chaetae in one specimen. Legs scaled to tibiotarsus. Tibiotarsus III with one ventral spine-like chaeta, tibiotarsi I and II without spine-like chaetae (formula 001) ( Fig. 29 ); claw long and narrow, with one small internal unpaired tooth (basal to the both internal lamellae, on which in some specimens there are two small teeth), at 20% of distance from the claw base ( Figs 30 , 34, 34 ’); Emp. swollen basally, with 0–3 teeth in two internal lamellae starting from middle point and extending basally. Tenent hair acuminate, 3.3 times the length of claw III (3.5 in the holotype); ratio claw III, Emp. III and tenent hair 3.27: 1.75: 1 (n = 4); claw with a thin pseudonychium, 0.37 times length of inner edge of claw, and paired basal lateral teeth. Tenaculum with 4 + 4 teeth ( Fig. 31 ); presence of chaetal socket not uncertain.

Ratio of manubrium: dens: mucro 4.83: 7.67: 1 (n = 3); outer margin of dens with 3 thick, spine-like chaetae; dental formula variable: 5– 7 I–II / 3– 6 I 2– 4 I 1– 6 I to 4– 5 I 1– 4 I 1– 2 I 1 I 1– 3 I (the Arabic numbers means the number of small spines; dental large spines in Roman, bold and in italics) ( Fig. 32 ); mucro with two basal and two distal teeth ( Fig. 33 ).

Chaetotaxy. Dorsal Mac on each side: Th. II without macrochaetae; Th. III with 1 macrochaeta (p3); Abd. I–V with 3 (m2, m3, m4), 3 (m2, m3, m4), 4 (m2, m6, p1, p6), 1 (E3) 3 (p2, p3, p4) Mac, respectively. Bothriotrichal formula 0/ 2–1/0–0–1–2–0; each bothriothrix bordered anteriorly with 1–7 small chaetae. Macrochaetotaxy and bothriotrichal patterns as in Figs 35–37 .

Discussion. Plutomurus eristoi sp. nov. is most similar to P. iwatensis Yoshii, 1991 , P. kawasawai Yosii, 1956 and P. ortobalaganensis Jordana & Baquero, 2012 in Jordana et al. 2012 based on the following characters: absence of eyes, presence of 3 + 3 prelabral chaetae, presence of pointed tenent hair and absence of subapical teeth or denticles on mucro. All of these species are cave dwellers. The new species differs from P. i w a t e n s i s, P. kawasawai and P. ortobalaganensis in the shape of claw and Emp. Plutomurus eristoi sp. nov. has a long, narrow claw, and a basally swollen and apically distinctly pointed Emp., while the claw and Emp. shape of the three similar species mentioned above are typical for the genus Plutomurus , that is a wide claw, widest at base, and pointed Emp., not basally swollen. The new species differs from P. iwatensis by the number of distal teeth on mucro (two in the new species, four in P. i w a t e n s i s). P. eristoi sp. nov. differs from P. kawasawai in the number of spine-like chaetae on the hind tibiotarsus (1 vs. 2 in P. ka w as a w a i), and in the presence of empodial teeth in the new species and their absence in P. kawasawai . Plutomurus eristoi sp. nov. has 1 spine-like chaeta on the hind tibiotarsus, whereas P. ortobalaganensis has 2; and the new species lacks macrochaetae on Th. II and has one on Th. III, while Th. II and III have 6 and 2 macrochaetae, in P. ortobalaganensis respectively.

Etymology. The species is dedicated to Dr. Eristo Kvavadze, who was supervisor of the first author.

Ecology. Plutomurus eristoi sp. nov. is probably troglophilous species, as it possesses pigmented body and eye patches.

Figures

FIGURE 34. Plutomurus eristoi sp. nov. claw III and Emp. III (bar: 0.02 mm); (34 ’, arrow shows the confluence of the two internal lamellae in the middle of Emp.

FIGURES 25 – 33. Plutomurus eristoi sp. nov. 25, labrum (bar: 0.05 mm); 26, labial palp (bar: 0.025 mm); 27, outer lobe of maxillary palp (bar: 0.02 mm); 28, trochanteral and femoral organs (bar: 0.05 mm); 29, leg III tibiotarsus, showing the location of the spine-like chaetae (bar: 0.05 mm) (some ordinary chaetae are illustrated for comparison); 30, claw III and Emp. III (bar: 0.05 mm); 31, tenaculum (bar: 0.04 mm); 32, spines on dens (bar: 0.05 mm); 33, mucro (bar: 0.025 mm).

FIGURES 35 – 37. Plutomurus eristoi sp. nov. dorsal chaetotaxy: 35, head; 36, Th. II – III; 37, Abd. I – VI (The meaning for the symbols is the same as in Figs 22 – 24).