Pygmarrhopalites principalis skelicus, Vargovitsh, Robert S., 2009

Vargovitsh, Robert S., 2009, New Cave Arrhopalitidae (Collembola: Symphypleona) from the Crimea (Ukraine), Zootaxa 2047, pp. 1-47 : 36-41

Pygmarrhopalites principalis skelicus ssp. nov.

Figs 144–171 , Table 3

Diagnosis. Body with weak reddish-brownish spotted pigmentation, eyes pigmented; trichobothrium B somewhat out of AC (ABC=~160o) and AB<BC; mesothorax with thickened dorsal setae; posterior dorsal setae of great abdomen as long as hind claw and longer; antenna in females 2 times as long as head; Ant IV with 5–7 subsegments; head with 4 + 4 spine-like setae; all claws with inner tooth, mid and hind claw with tunica; empodia with apical filament overtopping tip of claw, fore and mid empodia with, and hind – without corner tooth; trochanter II with 5 setae; tenaculum with 2 setulae; manubrium with 7 + 7 setae; dens with 5 spines or spiny setae, Ie very strong and looks somewhat articulated, anteriorly with 3, 2, 1, 1 setae; tip of mucro broadened or rounded; small abdomen with rather strong but not broadened circumanal setae and axial seta ms1 not forked; appendices anales palmate.

Material examined. Holotype on slide (C-277-1): female, Ukraine, Crimea, Aj-Petri Massif, Skelskaya Cave, 14.viii.1998. Paratypes on slides: 8 males, 23 females, 5 juv., collected together with holotype. Holotype and 34 paratypes are preserved in SIZNAS, 2 paratypes in SNHML.

Other material (on slides). Aj-Petri Massif: female, Kaskadnaya Cave (- 100 m), 17.viii.1998; 2 males, female, 3 juv., same cave (- 100 m, - 150 m), 20.viii.1998; male, female, 8 juv., Drugaya Cave (- 27 m), 1.viii.2005; male, female, 200-4 Cave (- 23 m), 1.viii.2005; 2 females, juv., Kamnepadnaya Cave (- 105 m), 29.vii.2005; 2 females, Oreshek Cave (- 25 m), 28.vii.2005; male, Paniya Cave (- 17 m), 2.viii.2005; 5 females, Bakhchisarai Distr., Vil'ya-Burun Mt., Vilyaburunskaya Cave, traps, 19.vii.2004 – 17.vii.2006. A.G. Koval leg. Besides slides, part of material is preserved in alcohol.

Description. Female: body ( Fig. 144 ) length 1–1.3 mm, dorsally with reddish-brownish pigmentation, sometimes unpigmented.

Head ( Fig. 145 ): Eyes 1 + 1, more or less pigmented (with pigmented spots in alcohol and clear on slides). Clypeal area with axial seta in row a. Interantennal area with axial seta in row β. Frontal area with 3 axial setae in rows A, B and C. 8 setae of frontal area are weakly spine-like (in row C: 2 + 2; D: 2 + 2) ( Fig. 151 ).

Antennae 1.9–2.1 times as long as head. Ant I: II: III: IV = 1: 2.1–2.5: 3.3–4.2: 8.3–10.2. Ant I with 7 setae; Ant II with 15 setae ( Fig. 158 ). Ant III ( Fig. 159 ): slightly thickened in subbasal – middle part, with 18 setae and 2 sense rods; seta Aai very small and curved; setae Api and Ape shorter and thinner than others. Ant IV ( Fig. 160 ) usually distinctly subdivided into 5 (rarely 6 or 7) subsegments with 13(12) setal whorls. If 5 subsegments present, basal one is 1.6–1.8 times as long as apical one and 1–1.1 times as long as Ant III. Subsegmental formula: 1 + 3 + 1 = (A + M1–M2) + (M3–M5) + (B).

Foreleg: precoxae and coxa with 1, 0, 1 setae respectively ( Fig. 146 ). Trochanter with 3 anterior and 1 posterior setae; femur with 12–13 setae ( Fig. 163 ), seta a 4 turned perpendicularly to the longitudinal axis of the segment. Tibiotarsus ( Fig. 164 ) with 3 setae FP and seta FSa; whorl I with 9 setae among which Ja is curved and spiny; each of whorls II–V with 8 setae. Claw without tunica, with inner tooth and 2 pairs of lateral teeth; empodium narrow, with corner tooth, apical filament exceeding claw ( Fig. 164 ). Claw 4.0–4.6 times shorter than tibiotarsus.

Mid leg: precoxae 1, 2 and coxa with 1, 1, 3 setae respectively ( Fig. 146 ). Trochanter with anterior trochanteral organ, 3 anterior and 1 posterior setae; femur with 14 setae ( Fig. 166 ). Tibiotarsus ( Fig. 165 ): 3 setae FP and seta FSa present; whorl I with 9 setae, each of whorls II–IV with 8 setae, whorl V with 7 setae. Claw with tunica, broader than in foreleg, with inner tooth and 2 pairs of lateral teeth; empodium broadened in basal half, with corner tooth and apical filament exceeding claw ( Fig. 165 ). Claw 4.5–5 times shorter than tibiotarsus.

Hind leg: precoxae and coxa with 1, 1, 3 setae respectively ( Fig. 146 ). Trochanter as in mid leg; femur with 14 setae: 2 posterior ones are very small ( Fig. 167 ). Chaetotaxy of tibiotarsus as in mid leg. Claw with tunica, a little broader than mid claw, with inner tooth and 2 pairs of lateral teeth; empodium broader than in mid leg, without tooth, apical filament exceeding claw ( Fig. 168 ). Claw 5.5–6.2 times shorter than tibiotarsus.

Length ratio of tibiotarsi I: II: III = 1: 1–1.1: 1.3.

Ventral tube with 2 small subapical setulae, smooth and long eversible sacks. Tenaculum ( Fig. 157 ): rami 3-dentate, with basal appendage; anterior lobe with 2 apical setulae; tip of posterior lobe exceeding tip of anterior lobe.

Furca ( Fig. 171 ): manubrium with 7 + 7 posterior setae. Dens: setae Ie, Ii, IIpe, IIIpi and IVpi are spinelike; outer spine Ie very strong, elongated and looks somewhat articulated ( Fig. 156 ); setae Ipe, IIIpe–Vpe simple; 3, 2, 1, 1 setae on anterior side ( Fig. 171 ; Table 3). Tip of mucro rounded, slightly broadened ( Fig. 162 ). Dens 1.5–1.7 times as long as mucro.

Great abdomen ( Fig. 146 ): mesothorax with spiny dorsal setae ( Fig. 150 ), which are longer than other anterior setae ( Fig. 149 ); posterior lateral complex with 6 setae; furca base complex with 9 setae; ventral complex with 3 setae; posterior dorsal complex with setae at least as long as hind claw ( Fig. 148 ); the most posterior seta of dI-row ( Fig. 147 ) is 1.5 times longer than hind claw and longer than axial seta ms1 of Abd VI ( Fig. 153 ). Trichobothrial complex: AB a little shorter than BC; ABC form an angle about 160o. Single seta of p-row of Abd I is located below the level of trichobothrium B anteriorly to the trichobothrial complex (marked with arrow); seta b1 lies close to the line between trichobothria B and C; seta c1 of thichobothrial complex lies on the level of trichobothrium C or lower.

Fifth abdominal segment with trichobothrium D and 4 setae ( Fig. 146 ).

Sixth abdominal segment ( Fig. 169 ): circumanal setae strong but not much thickened ( Figs 152, 153 ). Appendices anales inserted in papilla, turned towards genital opening and palmated in distal part ( Figs 154–155 ); about 1.3 times shorter than hind claw.

Male: body length 0.65–0.9 mm. Antenna: head = 1.9–2.2. Ant I: II: III: IV = 1: 2.1–2.4: 3.7–3.9: 8.9–10.3. Ant IV subdivided into 7–8 subsegments; one or two basal subsegments separated by weak annulations ( Fig. 161 ). Abd VI as in Fig. 170 .

Bionomy and distribution. In most caves specimens were taken from water surface of small pools, from stalagmites and walls, and from the wooden substance. In Kaskadnaya Cave specimens were collected from litter penetrating into the cave from surface down to - 150 m vertical depth. Troglophile or “recent” troglobite. Subspecies is distributed only in Western biospeleological region, sometimes shares caves with P. tauricus sp. nov. and A. peculiaris sp. nov. and shows allopatric mode of distribution with close related variance of P. principalis from Chatyr-Dag and P. pseudoprincipalis sp. nov. from two massifs of Eastern biospeleological region ( Table 1 ).

Etymology. The new subspecies is named after type locality, Skelskaya Cave.

Variability. Ant IV in females normaly with 5, rarely 6 or even 7 subsegments, in males 7–8 subsegments. Whorl BM2 of Ant IV with 0 to 4 setae. Seta pi2 of fore femur present or absent.

Remarks. The new subspecies generally fits to Stach’s (1945) description of P. principalis (appendices anales, strong but not winged circumanal setae, foot complex, dens chaetotaxy and shape of mucro tip, antennae), although some important features (number and shape of cephalic spines, shape of axial seta ms1 on small abdomen) are not mentioned in original description. Subsequently these important features were described by Gisin (1947) but his figures of mucro and winged circumanal setae contradict with original description; besides, the size of animals from Stach’s and Gisin’s descriptions is quite different (adult female not less than 1 mm and 0.6–0.75 mm respectively). Until full redescription of P. principalis sensu Stach, 1945 (especially such critical features as bifurcated or not axial seta ms1 of small abdomen and number and shape of cephalic spines) we consider subspecies described above as belonging to this species but with different antenna/head ratio (antennae 2 times as long as head instead of 1.3–1.6 times) and female with normally 5 subsegments in Ant IV.

P. principalis skelicus ssp. nov. is also very close to described above P. pseudoprincipalis but differs from it in following features: 1) broadened tip of mucro; 2) longer antennae; 3) not thickened setae Ipe, IIIpe–Vpe of dens; 4) longer dorsal posterior setae of great abdomen and longer setae of a and m rows of Abd VI; 5) less palmated appendices anales; 6) somewhat greater ratio ‘dens: mucro’.

Specimens belonging to P. principalis were found also in caves of Chatyr-Dag Massif ( Table 1 ). However, intraspecific taxonomical position of population from Chatyr-Dag remains unclear: Ipe, IIIpe–Vpe setae of dens thickened as in P. pseudoprincipalis , but body proportions more close to P. principalis skelicus and mucronal apex more swollen than in last subspecies. It is possible that specimens from Chatyr-Dag represent an independent subspecies. The question of geographical variability and intraspecific taxonomical borders of conspecific Crimean populations of P. principalis and their relation to P. pseudoprincipalis requires additional study.

Figures

FIGURES 144 – 157. Pygmarrhopalites principalis skelicus ssp. nov.: 144, outline of habitus; 145, chaetotaxy of head, frontal view; 146, chaetotaxy of great abdomen, lateral view; 147 – 156, shape of setae: (dI- 1) of great abdomen (147), posterior dorsal seta of great abdomen (148), anterior dorsal seta of abdomen (149), dorsal spine-like seta of mesothorax (150), spine-like seta of head vertex (151), (mps 2) of Abd VI (152), (ms 1) of Abd VI (153), appendices anales, dorsal (154) and lateral view (155), (Ie) of dens (156); 157, tenaculum.

FIGURES 158 – 162. Pygmarrhopalites principalis skelicus ssp. nov.: 158 – 160, chaetotaxy of antennal segments, anterior view: Ant I – II (158), Ant III (159), Ant IV (160); 161, outline of antenna of male; 162, apex of mucro.

FIGURES 163 – 171. Pygmarrhopalites principalis skelicus ssp. nov.: 163, 166 – 167, chaetotaxy of trochanter and femur, anterior view: foreleg (163), mid leg (166), hind leg (167); 164 – 165, chaetotaxy of tibiotarsus and foot complex: foreleg, posterior view (164), mid leg, anterior view (165); 168, foot complex of hind leg; 169 – 170, chaetotaxy of Abd VI, lateral view: female (169) and male (170); 171, chaetotaxy of furca, posterior view.