Plusiocampa (Plusiocampa) imereti Sendra & Barjadze, 2021

Sendra, Alberto, Palero, Ferran, Sánchez-García, Alba, Jiménez-Valverde, Alberto, Selfa, Jesús, Maghradze, Eter & Barjadze, Shalva, 2021, A new Diplura species from Georgia caves, Plusiocampa (Plusiocampa) imereti (Diplura, Campodeidae), with morphological and molecular data, European Journal of Taxonomy 778, pp. 71-85 : 74-79

Plusiocampa (Plusiocampa) imereti Sendra & Barjadze sp. nov.

urn:lsid:zoobank.org:act:40C3DB96-19CD-4354-ACA9-434F0ADA34BB

Figs 2‒12

Diagnosis

Troglomorphic species. Antennae with 39–45 antennomeres; 12 complex olfactory chemoreceptors within cupuliform organ; non-protruding frontal process slightly protruding, plain, with non-tubercular setae or just slightly tubercular. Pronotum 1+1 ma, 2+2 la 1,2, 2+2 lp 2,3; mesonotum with 1+1 ma, 3+3 la 1–3, 2+2 lp 2,3, 1+1 mp; metanotum with 1+1 ma, 2+2 la 1,2 or sla 1,2, 1+1 lp 2, 1+1 mp; thin; all notal macrosetae long and covered by thin barbs on half to distal portions; thin, middle-sized clothing setae covered by 0–4 thin distal barbs. Legs elongated, pretarsus of metathoracic legs slightly overpasses end of abdomen. Femora I–III with one long, barbed dorsal macroseta and one shorter, barbed ventral macroseta. Tibiae I–III with two short barbed ventral macrosetae. Claws unequal (posterior claw 1.3 × as long as anterior one); large, backward overhang on posterior claw; lateral crests well-developed. Pretarsal process long and setiform. Urotergites 1+1 post 1 on I–II; 0+0, 0+1 or 1+1 la, 1+1 or 2+2 post 1,2 on III; 1+1 la

3

, 2+2 to 4+4 post

1–4

on IV; 2+2 la

2,3

, 4+4 post

1–4

on V–VII; 6+6 post

1–6

on VIII and 8+8 or 8+7 post 1–8 on abdominal IX. Urosternite I with 8+8–7+7 macrosetae ( Figs 8–9 ); urosternites II–VII with 6+6 macrosetae; urosternite VIII with 2+2 macrosetae. Male urosternite I ( Fig. 8 ) with slightly enlarged subcylindrical appendages, each bearing up to 21 glandular a 1 setae. Female appendages slightly thinner, with up to 11 glandular a 1 setae.

Etymology

The specific epithet refers to the Imereti region, the location of the Shvilobisa Cave, treated as a noun in apposition.

Type material

Holotype GEORGIA • ♀, “holotype-♀ IZISU-TD-T-00001”; Shvilobisa Cave, Bunikauri village, Chiatura Municipality , Imereti region, Zemo Imereti Plateau; 42°19′31.44″ N, 43°16′4.33″ E; 24 Feb. 2018; Shalva Barjadze and Eter Maghradze leg.; IZISU-TD-T-00001 .

Paratypes GEORGIA • 1 ♂, “paratype-♂1 IZISU-TD-T-00002”; same collection data as for holotype; IZISU- TD-T-00002 • 1 ♀, “paratype-♀1 MZB (MCNB) 2021-2336”; same locality as for holotype; 20 Jul. 2020; Eter Maghradze leg.; MZB ( MCNB) 2021-2336 • 1 ♀, “paratype-♀2 MZB (MCNB) 2021-2337”; same collection data as for preceding; MZB ( MCNB) 2021-2337 • 1 ♂, “paratype-♂2 Coll AS”; same collection data as for preceding; Coll AS .

Other material

GEORGIA • 2 specs, unknown sex [for SEM photography and one specimen for DNA analysis]; Shvilobisa Cave ; 24 Feb. 2018; Shalva Barjadze and Eter Maghradze leg . • 2 specs [for SEM photography and one for DNA analysis]; same collection data as for preceding; 20 Jul. 2020; Eter Maghradze leg.

Other material from two other caves (all Coll AS)

GEORGIA • 1 ♀; Kumistavi village Tskaltubo Municipality, Imereti Region, Sataplia-Tskaltubo karst massif , Datvis (Bear) Cave ; 42°22′28 ″ N, 42°35′45″ E; 5 Jul. 2018; Eter Maghradze leg. • 1 ♀; same collection data as for preceding; 1 Sept. 2019 • 1 ♂; near Melouri village, Tskaltubo Municipality, Imereti Region, Sataplia-Tskaltubo karst massif , Melouri Cave ; 42°23′15.1″ N, 42°37′41.5″ E; 1 Nov. 2018; Eter Maghradze leg.

Description

BODY. Body length 4.3–7.2 mm (females) and 4.9–5.2 mm (males) ( Table 1 ). Epicuticle smooth under optical microscope and SEM; body with thin, middle-sized clothing setae covered by 0–4 thin distal barbs.

HEAD. Three intact antennae, all slightly longer than body length, with 39–45 antennomeres ( Table 1 ). Small, thin, subcylindrical sensillum on third antennomere located in ventral position between c and d macrosetae. Central antennomeres 2.1 × as long as wide, apical antennomere 3.0 × as long as wide. Cupuliform organ occupying ⅓ of total length of apical antennomere, with about 12 complex olfactory chemoreceptors. Each olfactory chemoreceptor is composed of a complete fold surrounding a central cylinder with two lateral expansions, entirely reticulated and perforated ( Fig. 5 ). Gouge sensilla 30– 40 μm long, in a single distal whorl of 13–16 sensilla on each medial and distal antennomere. Frontal process slightly protruding, plain, with non-tubercular setae or just slightly tubercular on distal portion ( Fig. 3 ); macrosetae along the insertion line of antennomere and i macrosetae and x setae longer than other macrosetae (a / i / p/ x with relative lengths of 25 / 36 / 19 / 37 in holotype). Suboval labial palps with a bacilliform latero-external sensillum, two guard setae, up to 7 setae on anterior border, and up to 130 neuroglandular setae in holotype.

THORAX. Thoracic macrosetal distribution ( Figs 2, 4, 6 ): pronotum with 1+1 ma, 2+2 la 1–2, 2+2 lp 2,3; mesonotum with 1+1 ma, 3+3 la 1–3, 2+2 lp 2,3, 1+1 mp; metanotum with 1+1 ma, 2+2 la 1,2 or sla 1,2, 1+1 lp 2, 1+1 mp. All notal macrosetae are long and covered by thin barbs on half to distal portions ( Figs 4, 6 ); submacrosetae sla are thinner and shorter than notal macrosetae; marginal setae are similar to clothing setae, and covered by 1–8 thin distal barbs. Legs elongated, pretarsus of metathoracic legs slightly overpasses end of abdomen ( Table 1 ). Femora I–III with one long, barbed dorsal macroseta and one shorter, barbed ventral macroseta. Tibiae I–III with two short barbed ventral macrosetae. Calcars with 4–5 long barbs. Tarsi with two rows of thicker ventral setae with 2–3 very thin barbs on middle portion. Two dorsal and one ventral, smooth, subapical tarsal setae. Claws are unequal (posterior claw 1.3 × as long as anterior one); large, backward overhang on posterior claw; lateral crests well-developed. Pretarsal process long and setiform, overpassing end of claws.

ABDOMEN. Distribution of abdominal macrosetae on tergites ( Fig. 7 ): 1+1 post 1 on I–II; 0+0, 0+1 or 1+1 la, 1+1 or 2+2 post 1,2 on III; 1+1 la 3, 2+2 to 4+4 post 1–4 on IV; 2+2 la 2,3, 4+4 post 1–4 on V–VII; 6+6 post 1–6 on VIII and 8+8 or 8+7 post 1–8 on abdominal segment IX. All post urotergal macrosetae long and covered by thin barbs along distal four-fifths ( Fig. 10 ); la urotergal macrosetae shorter than post macrosetae, covered by barbs along distal half. Urosternite I with 8+8–7+7 macrosetae ( Figs 8–9 ); urosternites II–VII with 6+6 macrosetae; urosternite VIII with 2+2 macrosetae ( Fig. 12 ); all urosternal macrosetae robust and large, covered by long barbs along distal third to four-fifths. Apical, subapical and ventromedial setae with a few (two to four) thin, short and long barbs ( Fig. 11 ).

SECONDARY SEX CHARACTERS. Male urosternite I ( Fig. 8 ) with slightly enlarged subcylindrical appendages, each bearing up to 21 glandular a 1 setae. Female appendages slightly thinner, with up to 11 glandular a

1

setae. Spermatozoid fascicles 40 μm in diameter without apparently spiral filament.

Molecular analysis

The nucleotide substitution model selected was GTR+G+I (BIC = 6998.6), with the proportion of invariant sites (I = 0.46) and estimated alpha parameter for the gamma distribution (α = 1.39), indicating a significant heterogeneity in the DNA substitution among sites. The Campodeidae sequences formed a well-supported clade, clearly distinct from that of Japygidae ( Fig. 13 ). Although bootstrap values were low, the ML phylogenetic tree grouped Plusiocampa (P.) imereti Sendra & Barjadze sp. nov. with Eastern Europe taxa such as Plusiocampa (Plusiocampa) aff. elongata Ionescu, 1955 and Plusiocampa (Plusiocampa) humicola Ionescu, 1955 , whereas Iberian Peninsula taxa ( Plusiocampa (Plusiocampa) gadorensis Sendra, 2001 , Plusiocampa (Plusiocampa) baetica Sendra, 2004 and Cestocampa iberica Sendra & Condé, 2012 ) clustered in a distinct clade. K2P genetic distances also showed P. (P.) aff. elongata (0.206± 0.027) and P. (P.) humicola (0.205 ± 0.028) to be the closest species to the new Plusiocampa (P.) imereti Sendra & Barjadze sp. nov. from Georgia.

Habitat

Plusiocampa (Plusiocampa) imereti Sendra & Barjadze sp. nov. inhabits the deep zone (over 50 m from the entrance) of three caves. The Shvilobisa Cave, the type locality, is a 1000 m long, tunnellike, easily accessible sub-horizontal cave with a small subterranean water stream ( Tatashidze et al. 2009b). The others two nearby caves are about 55 km away from the Shvilobisa Cave; the Melouri Cave is 5300 meters long and has the status of natural monument ( Tatashidze et al. 2009b), whereas the Datvis Cave is a poorly known cavern (K. Tsikarishvili, pers. comm.). The distance between the Datvis and Melouri caves is ca 3.5 km. The Melouri Cave – easily accessible – has dried halls and a permanent subterranean water stream near its end. This cave has gigantic stalagmites and fallen stones. The Datvis Cave is a horizontal, dry, and easily accessible cave with several halls, which are rich in different speleothems like the Shvilobisa Cave ( Tatashidze et al. 2009b).

Invertebrate cavernicolous species of the studied caves

The three caves (Shvilobisa, Datvis, and Melouri) which Plusiocampa (Plusiocampa) imereti Sendra & Barjadze sp. nov. inhabits are also the dwellings of other troglobitic arthropod species. Datvis and Melouri caves share three troglobitic species: the Diplopoda Leucogeorgia prometheus Antić & Reip, 2020 , the Isopoda Colchidoniscus kutaissianus Borutzky, 1974 , and the Pseudoscorpionida Chthonius satapliaensis Schawaller & Dashdamirov, 1988 . In addition, the Insecta ( Carabidae Coleoptera ) Troglocimmerites imereti Dolzhanski & Ljovuschkin, 1985 dwells in the Datvis cave; and the Melouri Cave has five more species: the Opiliones Nemaspela melouri Martens, Maghradze & Barjadze, 2021 , the Araneae Centromerus bulgarianus Drensky, 1931 , the Hexapoda Collembola Pseudacherontides zenkevitchi Djanashvili, 1971 ; the Insecta ( Carabidae Coleoptera ) Inotrechus kurnakovi Dolzhanski & Ljovuschkin, 1989 ; and Troglocimmerites sp. 1 . In the Shvilobisa Cave, eight troglobitic species dwell: the Diplopoda Leucogeorgia gioi Antić & Reip, 2020 , the Isopoda Caucasonethes cf. borutzkyi Verhoeff, 1932 and Colchidoniscus sp. , the Pseudoscorpionida Chthonius satapliaensis Schawaller & Dashdamirov, 1988 , the Opiliones Nemaspela sp. , the Hexapoda Collembola Oncopodura sp. and Pseudosinella sp. , and the Insecta ( Carabidae Coleoptera ) Troglocimmerites sp. 2 . ( Barjadze et al. 2019; Maghradze et al. 2019; Antić & Reip 2020; Martens et al. 2021; Maghradze & Barjadze, unpublished data).

Figures

Figs 2–6. Plusiocampa (Plusiocampa) imereti Sendra & Barjadze sp. nov., ♀, holotype (IZISU- TD-T-00001). 2. Thoracic nota. 3. Frontal process. 4. Detail of mesonotum. 5. Detail of mesonotum at high magnification. 6. Detail of metanotum.

Figs 7–12. Plusiocampa (Plusiocampa) imereti Sendra & Barjadze sp. nov., ♀, holotype (IZISU- TD-T-00001). 7. Urotergites I–IX. 8. First urosternite of the male, lateral side. 9. Macrosetae of first urosternite of the male. 10. Detail of sixth urotergite. 11. Detail of six urosternite. 12. Eight urosternite of male. a 1 = glandular setae on distal portion of appendages.

Fig. 13. Maximum likelihood (ML) tree of Diplura obtained from CO1 data. Only bootstrap support values above 70 are shown.

Tables

Table 1. Measurements for Plusiocampa (Plusiocampa) imereti Sendra & Barjadze sp. nov. Body length, antennae and metathoracic leg articles (in mm), and number of antennomeres.

Specimens	Body length	Antennae		Metathoracic legs
		Length	Antennomeres	Coxa	Trochanter	Femur	Tibia	Tarsus & pretarsus
holotype ♀ IZISU-TD-T-00001	7.2	–	–	0.4	0.4	1.1	1.3	0.9
paratype- ♀ 1 MZB (MCNB) 2021-2336	6.0	6.5	44	0.3	0.3	0.9	1.0	0.8
paratype- ♂ 1 IZISU-TD-T00002	5.2	6.5	39	0.2	0.2	0.9	1.0	0.8
paratype- ♂ 2 Coll AS	4.9	6.0	45	0.2	0.2	0.8	0.9	0.7
paratype- ♀ 2 MZB (MNCB) 2021-2337	4.3	–	–	0.2	0.2	0.8	0.9	0.7