Plutomurus revazi, 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 : 81-84

Plutomurus revazi sp. nov.

Figs 5–24 , Table 2

Type locality. GEORGIA, Imereti region, Tskaltubo district, Kumistavi village, Sataplia-Tskaltubo karst massif, Satsurblia Cave, 42°23'16.59"N, 42°36'22.35"E, 290 m. alt.

Type material. Holotype, female in slide: dark zone, 30.xi.2014 (code CAU-SATSURBLIA 20141130 01). Paratypes (same data as holotype): three females in slide, dark zone, 30.xi.2014 ( CAU SATSURBLIA 20141130 0 3, 0 7, 09); one male in slide, dark zone, 30.xi.2014 ( CAU SATSURBLIA 20141130 04); two females in slide, twilight zone, 30.xi.2014 ( CAU SATSURBLIA 20141130 0 8 and 10); five females in slide, dark zone, 24.i.2015 ( CAU SATSURBLIA 20150124 0 2, 0 5, 0 6, 11, 12); one specimen mounted on SEM stub ( CAU SATSURBLIA 20141130 13). Deposited material: holotype and paratypes 0 4, 0 6 and 0 8 in MZNA; remaining paratypes in ISU.

Complementary material. Six specimens in slide (codes CAU PROMETHEUS- 20141130 0 1 to 06), and two specimens mounted on SEM stub ( CAU PROMETHEUS 20141130 0 7 and 08), from GEORGIA, Imereti region, Tskaltubo district, Kumistavi village, Sataplia-Tskaltubo karst massif, Prometheus Cave, 42°22'38.05" N, 42°36'3.40" E, 175 m. alt., dark zone, 30.xi.2014. Specimens 0 1 and 0 4 in MZNA, the rest in ISU.

The new species was previously mentioned from Prometheus and Satsurblia caves as “ Plutomurus sp. 2” (Barjadze et al. 2015).

Description. Body length up to 5.6 mm excluding antennae (holotype 3.6 mm) (Satsurblia Cave, mean 4.56 mm, n = 10; Prometheus Cave, mean 3.42 mm, n = 6). Body cuticular, colour brownish-grey, with patches of darker pigmentation over the whole body except on antennae, legs and dens; scales covering antennal I and II segments, head, body and legs; colour and scale patterns, and habitus as in Figs 5–6 .

Head. Eye patch small, eyes not visible under light microscope, while in SEM exterior faded 3-4 (5) cornea present. Ratio of body length to antennae length up to 1.31 (holotype 1.02) (Satsurblia Cave, mean 1.18, n = 6; Prometheus Cave, mean 0.99, n = 6). Prelabral chaetae 3 + 3; labrum with 5, 5, 4 chaetae arising from tubercles and with four curved hooks on distal part of labrum ( Fig. 7 ). Maxillary palp trifurcate, chaeta on distal papilla longer than basal papilla; sublobal plate with four sublobals, all shorter than basal chaeta ( Fig. 9 ). Labial papillae as in Fig. 8 ; proximal labial chaetae up to 16; labial chaetae smooth.

Body. Third legs with well developed trochanteral and femoral organs, with about 17 and 40 chaetae respectively, a few chaetae longer than others ( Fig. 10 ). Ventral tube with 65 distal, 49 + 49 anterior and 54 posterior chaetae in one specimen. Legs scaled to tibiotarsus. Tibiotarsus III with two ventral spine-like chaetae ( Fig. 11 ), such chaetae absent on tibiotarsi I to II (formula 002). Claw on all legs with characteristic small, unpaired tooth between the two lamellae ( Figs 12–14 , 18 ); number of internal unpaired teeth varying from 2 to 5, ( Table 2), with a minute basal tooth at 20–40% of the claw length from the base, at base of the two internal lamellae; three unpaired teeth usually present, second and third teeth occasionally absent, formed by the fusion of both lamellae; distal tooth formed by terminal fusion of lamellae ( Fig. 18 ’); Emp. blade-like, usually with two internal serrated lamellae bearing 0–8 teeth starting near distal part and extending to base ( Figs 12–14 , 18–19 ; Table 2). Tenent hair long, clavate. Ratio of claw III: Emp. III: tenent hair 1.8: 1.1: 1 (holotype); claw with a thin pseudonychium, 0.76 times length of inner edge of claw and two basal and lateral teeth. Tenaculum with 4 + 4 teeth and one chaeta on corpus ( Fig. 17 ). Ratio of manubrium: dens: mucro 5.7: 7.5: 1 (n = 8, including holotype). Outer margin of dens with four thick, spine-like chaetae; dental formula very variable ( Table 2) ( Fig. 16 ). Mucro with 2 basal, fused teeth, 0–2 intermediate denticles, and 2 distal teeth ( Fig. 15 ). Male genital plate in Figs 20–21 .

Chaetotaxy. Dorsally Mac on each side: Th. II–III with 5 (m3, m4, m5, p3, p4) and 2 (p3, p5) Mac, respectively; Abd. I–V with 3 (m2, m3, m4) 3 (m2, m3, m4) 4 (m2, m6, p1, p6) 3 (A6, C6, E3) and 3 (p2, p3, p4) Mac, respectively. Bothriotrichal formula 0/2–1/0–0–1–2–0. Bothriothrix bordered anteriorly by 1–3 small chaetae. Macrochaetotaxy and Bothriotrichal pattern as in Figs 22–24 .

Specimen Claw I Emp. I Claw II Emp. II Claw III Emp. III dens dens apical

number basal

Holotype 3+1b 3+3 2+1b 4+3 3+1b 5+4 7 III 7 I 2 I 3 I 3+1b 5+? 3+1b 4+3 3+1b 4+0 10 II 4 I 3 I 2 I

Paratype 1 3+1b 2+0 3+1b - 3+1b 5+ 3 23 II 4 I 7 I 2 I 1 I 0 I 3 +1b 5+2 3+1b 7+5 - - 9 II 3 I 5 I 2 I 2 I

Paratype 2 3+1b 4+3 2+1b 4+5 3+1b 6+ 6 14 I 5 I 5 I 4 I

2+1b 4+? 2+1b 4+? 3+1b - 17 III 4 I 5 I 1 I 4 I

Paratype 3 3+1b 4+5 3+1b 3+1 3+1b 6+ 3 15 III 2 I 2 I 3 I 4 I

3+1b 2+3 - 4+4 3+1b - - -

Paratype 4 3+1b 4+3 4+1b 8+3 2+1b 1+0 - -

3+1b 5+6 - - - - - -

Paratype 5 3+1b 2+0 3+1b - 3+1b 4+ 5 14 II 6 I 4 I 3 I

1+1b 3+? 3+1b 3+3 3+1b 4+ 5 12 III 5 I 3 I 3 I 2 I

Paratype 6 2+1b 3+4 3+1b 1+1 3+1b 3+4 9 II 9 I 5 I

1+1b 2+4 - - 3+1b 4+ 4 12 IV 5 I 3 I 3 I

Paratype 7 1+1b - 2+1b 4+5 1+1b 7+ 7 11 II 6 I 4 I 3 I

2+1b 4+3 1+1b 7+3 2+1b 3+ 4 12 II 3 I 6 I 2 I 3 I

Paratype 8 2+1b 3+2 - - 1+1b 6+? 12 II 9 I 2 I 3 I

2+1b 3+2 - - - - 9 II 5 I 2 I 2 I 3 I

Paratype 9 1+1b 3+4 1+1b 4+4? 1+1b 6+ 5 11 II 8 I 4 I 3 I 1+1b 4+? 1+1b 3+? 1+1b 6+ 4 15 II 8 I 2 I 4 I

Paratype 10 3+1b 4+3 4+1b 4+4 3+1b 6+0 - -

3+1b 2+2 4+1b 2+2 3+1b - - -

Paratype 11 3+1b 2+0 2+1b 4+? - - 17 II 2 I 5 I 3 I 3 I

3+1b 5+4 2+1b 2+1 - - 17 II 6 I 3 I 4 I

Range 1–3+ 1b 2–5+0–6 1–4+1b 1–8+1–5 1–3+1b 1–7+0– 7 7–23 9–15 small small 1– 2–5 big spines 4 big

spines

Variable characters. The number of inner teeth on claw is variable. In the 12 specimens examined the number of inner claw teeth vary from 2 to 5; the number of teeth on inner two lamellae of the Emp. vary from 0 to 8. The number of dental spines is also variable. The number of small basal dental spines ranges from 7 to 23. In paratype 1 the dental spine formula on one dens is 23 II / 4 I 7 I 2 I 1 I 0 I, whereas on the other it is 9 II / 3 I 5 I 2 I 2 I. In most specimens the mucro lacks intermediate denticles, but in some specimens 1 or 2 intermediate denticles are present.

Discussion. The new species is most similar to the North American P. grahami ( Christiansen, 1980) based on the following characters: apparently blind under light microscopy, presence of 3 + 3 prelabral chaetae, and presence of clavate tenent hair. Both are cave-dwelling species. The new species differs from P. grahami by: (1) the formula of spine-like chaetae on the tibiotarsi: 0 0 2 in P. revazi sp. nov., while it is 0 0 1 in P. grahami ; (2) dorsal macrochaetotaxy: 52/ 33433 in the new species, while it is 42/ 32413 in P. grahami .

Etymology. The species is dedicated to Dr. Revaz Djanashvili, who, beginning in the 1960s, was the first Georgian biospeleologist and collembolan taxonomist.

Ecology. It is probably troglophilous species, because the body and eye patches are pigmented.

Figures

FIGURES 5 – 6. Plutomurus revazi sp. nov. 5, habitus (light microscopy); 6, habitus (SEM) (bar: 0.4 mm).

FIGURES 7 – 14. Plutomurus revazi sp. nov. 7, labrum (bar: 0.04 mm); 8, labial palp (bar: 0.02 mm); 9, outer lobe of maxillary palp (bar: 0.02 mm); 10, trochanteral and femoral organs (bar: 0.06 mm); 11, leg III tibiotarsus, showing the location of the spine-like chaetae (bar: 0.06 mm) (some ordinary chaetae are illustrated for comparison); 12 – 14, claw and Emp. I – III respectively (bar: 0.05 mm) (a, basal tooth to internal lamellae; b, first unpaired tooth, the more developed, c and d, additional unpaired teeth; The arrows point each tooth).

FIGURES 15 – 17. Plutomurus revazi sp. nov. 15, mucro (bar: 0.03 mm) (The arrows show the presence of the two medial teeth); 16, spines on dens (bar: 0.05 mm); 17, tenaculum (bar: 0.03 mm).

FIGURES 18 – 21. Plutomurus revazi sp. nov. 18, SEM microphotograph of claw I and Emp. I (bar: 0.03 mm); 18 ’, detail of internal lamellae on claw I, showing teeth: a, basal to internal lamellae; b, first unpaired tooth, the more developed (broken), c and d, additional unpaired teeth, not always presents); 19, detail of Emp. I, showing the two internal ridges with three denticles on each (bar: 0.01 mm); 20, Abd. VI, ventral, view, and male genital plate (bar: 0.06 mm); 21, detail of male genital plate (bar: 0.02 mm).

FIGURES 22 – 24. Plutomurus revazi sp. nov., dorsal chaetotaxy: 22, head; 23, Th. II – III; 24, Abd. I – VI (dash-lined hollow circles represent eyes; large black circles represent macrochaetae; white circles represent mesochaetae or small macrochaetae; small black circles represent microchaetae; squares with a black dot represent bothriothrix; triangles are microsensillae; circles with a slash represent pseudopores).