Cibiniulus slovacus Antić, Mock & Enghoff, 2015

Antić, Dragan Ž., Mock, Andrej & Enghoff, Henrik, 2015, Two new species of the millipede family Blaniulidae (Diplopoda, Julida) from caves in central and southeastern Europe, Zootaxa 3985 (4), pp. 523-540 : 524-529

Cibiniulus slovacus Antić, Mock & Enghoff , sp. n.

Figs 1–12

Material studied. Holotype male ( ZMUC): Jazvínska Cave, Tribeč Mountains, Slovakia, pitfall traps, 14.04– 17.10 .2000, leg. Roman Mlejnek. Paratypes ( ZMUC): four females (one fragmented) same data as holotype; two females: Dobrotínska Cave, Tribeč Mountains, Slovakia, baited pitfall traps, 14.04– 17.10.2000, leg. Roman Mlejnek; one female and one male: Gemersko-teplická Cave, Slovak Karst, Slovakia, 27.07.2003, leg. Vladimír Papáč. Additional material: three females and one juvenile male: Kolónia II Cave, Volovské vrchy Mountain, Slovakia, 0 6.03.2010, leg. A. Mock.

Etymology. After Slovakia.

Diagnosis. Differs from Cibiniulus phlepsii by numerous aspects in both habitus and posterior gonopods (see Table 1 ), e.g., absence of ocelli and absence of a lateral lamella on the posterior gonopods. Differs from other blind blaniulids occurring in Central Europe by the habitus and setation of vulva: without setation in C. slovacus , but setose in B. guttulatus , A. pallidus and B. tenuis (cf. Broelemann 1923; Blower 1985).

Description. Holotype adult male: L 12.30 mm, H 0.48 mm, 48 podous + 2 apodous rings + telson. Paratype adult male: L 9.20 mm, H 0.48 mm, 41 podous + 2 apodous rings + telson. Paratype females up to L 18.5 mm, H 0.58 mm, 38–56 podous + 2 apodous rings + telson. Juvenile male with 33 podous +3 apodous ring + telson.

Colour. Depigmented, whitish to pale yellow.

Head. Without ocelli. Antennae quite long, length 203 % of H in paratype male, 188 % of H in female. Relative lengths of antennomeres 1–8 (8 = apical sensilla): 7/20/18 /14/ 16/14/7 /4 % in paratype male, 7/20/18 /15/ 17/13/7 /3 % in female. In males, mandibles with usual parrot-bill-like modification of cardo and stipes.

Midbody rings with ca. 12–14 setae on posterior margin, length of setae ca. 15–17% of H in both sexes. Latero-ventral sides of rings with longitudinal striations which extend into prozonites.

Legs: length 95 % of H in paratype male, 85 % of H in female. Relative lengths of podomeres from coxa to claw 17/14/12 / 8/13/23 /13 % in paratype male, 20/ 14/14/12 / 9/20/11 % in female; claw length/height 4.5 in paratype male and 4 in female. Lanceolate setae present on femur (1), postfemur (1) and tibia (2) in males.

First pair of male legs ( Figs 8 and 9 ) highly modified, incrassate. A narrow triangular area (tr) between prefemur and femur. Femur with characteristic longitudinal striations (fs). Tibia (ti) very robust, with two mesal apophyses/modified setae (a), laterally with anterior setiferous hump (sh). Tarsus (ta) in the form of a cap on top of tibia, carrying a rudimentary claw (cl).

Second pair of male legs ( Fig. 4 ) with two ventral, lanceolate setae (ls) on femur, postfemur and tibia in holotype male.

Penis ( Fig. 4 , p) simple, with rounded apex.

Ventral margin of pleurotergite 7 in males without a horizontal flange.

Anterior gonopods ( Figs 1–3 ) with separated slender coxal processes (cp) which are somewhat wider at the base, narrowing at the border between ⅓ and ⅔ of the length, and then gradually widening towards a rounded apex. A postero-mesal flange (f) extending almost the entire length of coxal process, with a thickening at the border between ⅓ and ⅔ of the length. Flange almost rectilinear in lateral view. Telopodites (t) rudimentary, less than ¼ the length of coxal processes, with 1+2 setae in holotype male, without setae in paratype male.

Posterior gonopods ( Figs 5–7 , 10 and 11 ) with prolonged sternum (s). Apical half with wide and thin leafshaped lamella (ll) divided into a dorsal, somewhat rounded lobe (dl), and a ventral, acuminate lobe (vl). Leafshaped lamella with numerous striations (st) which at first glance resemble setae. Lateral lamella completely absent. On the SEM images, the apical half of the posterior gonopods is distorted, probably due to the air-drying method employed.

Second pair of female legs without any peculiarities.

Vulvae ( Fig. 12 ) subspherical, operculum and bursa of about equal length, both without setae; receptaculum seminis (rs) single, ellipsoid. Vulval invaginations reaching back to ring five.

Note on habitat and coexisting species. The new Cibiniulus species was found in karstic caves, with the elevation of the entrances ranging from 255 to 800 m a.s.l. Some of the caves (Jazvínska, Dobrotínska, Kolónia II) are quite short (25-44 m), the last one (Gemersko-teplická Cave) has long a narrow corridor (510 m) with an underground stream. The cave floors are horizontal except for the cave Kolónia II (- 25 m). Specimens were collected on decaying wood or in pitfall traps (100 ml plastic bottles with a mixture of beer and ethyleneglycole with cheese or salami under the opening; the traps were placed deep in the debris). All records are from the inner part of the caves (deeper than 20 m). All of the caves have a well preserved environment and are not open to the public. There were no other obligate cavernicolous millipedes co-occurring with C. slovacus sp. n., but only common species like Polydesmus denticulatus C. L. Koch, 1847 (Jazvínska, Dobrotínska caves) or the eutroglophilous Trachysphaera costata (Waga, 1857) in the cave Kolónia II.

Note on cave adaptations. The depigmented body, the absence of ocelli and the somewhat elongated antennae of the new species are characters all shared with several other soil-dwelling blaniulids and cannot be regarded as troglomorphic traits. Thus, C. slovacus sp. n. should probably be classified as a troglophilic species.

Distribution. Known only from several caves in Slovakia ( Fig. 43 , green circles).

Figures

FIGURE 43. Distribution of the genera Cibiniulus Verhoeff, 1897 and Thassoblaniulus Mauriès, 1985.

FIGURES 1 – 4. Cibiniulus slovacus sp. n., paratype male. 1. anterior gonopods, posterior view; 2. anterior gonopods, posterolateral view; 3. anterior gonopods, lateral view; 4. second pair of legs with penis, posterior view. – f: postero-mesal flange, p: penis, t: telopodite, cp: coxal processes, ls: lanceolate seta. Scale lines: 0.1 mm.

FIGURES 5 – 9. Cibiniulus slovacus sp. n., paratype male. 5. posterior gonopod, lateral view; 6. apical half of posterior gonopod, lateral view; 7. posterior gonopod, mesal view; 8. left first leg, posterior view; 9. apical part of right first leg, anterior view. a: apophyses / modified setae, s: sternum, cl: claw, dl: dorsal lobe, fs: femoral striations, ll: leaf-shaped lamella, sh: setiferous hump, st: striations on leaf-shaped lamella, ta: tarsus, ti: tibia, tr: triangular area, vl: ventral lobe. Scale lines: 0.1 mm.

FIGURES 10 – 12. Cibiniulus slovacus sp. n., 10. holotype male posterior gonopods, lateral and mesal view; 11. holotype male posterior gonopods apex, lateral and mesal view; 12. female vulva, posterior view. s: sternum, dl: dorsal lobe, ll: leaf-shaped lamella, rs: receptaculum seminis, st: striations on leaf-shaped lamella, vl: ventral lobe.

Tables

TABLE 1. Differences between Cibiniulus phlepsii (Verhoeff, 1897) and C. slovacus sp. n.

Characters	Cibiniulus phlepsii (Verhoeff, 1897)	Cibiniulus slovacus sp. n.
Ocelli	Present	Absent
Antennae	Shorter	Longer
Tibia of first pair of legs in ♂♂	Without apophyses and without strongly developed antero-lateral hump	With two apophyses and with strongly developed antero-lateral hump
Tarsi of first pair of legs in ♂♂	Very low	In the form of a cap on top of tibia
Anterior gonopods with narrowing at border between:	second and third ⅓ of length of coxal processes	first and second ⅓ of length of coxal processes
Postero-mesal flange of anterior gonopods in lateral view	Bilobed	Almost rectilinear
Telopodites of anterior gonopods	Without setae	With or without setae
Posterior gonopods	With lateral lamella	Without lateral lamella
Dorsal lobe of mesal lamella of posterior gonopods	Acuminate	Almost rounded
Ventral lobe of mesal lamella of posterior gonopods	With fringes	Without fringes