Research Article |
Corresponding author: Nesrine Akkari ( nes.akkari@gmail.com ) Academic editor: Marzio Zapparoli
© 2017 Nesrine Akkari, Ana Komerički, Alexander M. Weigand, Gregory D. Edgecombe, Pavel Stoev.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Akkari N, Komerički A, Weigand AM, Edgecombe GD, Stoev P (2017) A new cave centipede from Croatia, Eupolybothrus liburnicus sp. n., with notes on the subgenus Schizopolybothrus Verhoeff, 1934 (Chilopoda, Lithobiomorpha, Lithobiidae). ZooKeys 687: 11-43. https://doi.org/10.3897/zookeys.687.13844
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A new species of Eupolybothrus Verhoeff, 1907 discovered in caves of Velebit Mountain in Croatia is described. E. liburnicus sp. n. exhibits a few morphological differences from its most similar congeners, all of which are attributed to the subgenus Schizopolybothrus Verhoeff, 1934, and two approaches to species delimitation using the COI barcode region identify it as distinct from the closely allied E. cavernicolus Stoev & Komerički, 2013.
E. spiniger (Latzel, 1888) is redescribed and a lectotype is designated for it as well as E. caesar (Verhoeff, 1899) to stabilize their respective taxonomic status. The subspecies E. acherontis wardaranus Verhoeff, 1937, previously suspected to be a synonym of E. caesar (Verhoeff, 1899), is redescribed and its taxonomy revised after the study of type material whereas the identity of E. acherontis (Verhoeff, 1900) described from a female from southwest Trebinje (Bosnia and Herzegovina) remains unknown. Type material of E. stygis (Folkmanova, 1940) is confirmed to be lost and future designation of neotypes from topotypic specimens is necessary to stabilize its taxonomy. The importance of setal arrangement on the intermediate and 14th tergites and the sexual modifications on the male 15th prefemur for species identification is discussed in the light of present findings, and a review of the species of E. (Schizopolybothrus) that display these traits is also provided.
Biospeleology, COI barcoding, Eupolybothrus , new species, SEM, Velebit Mountain
The genus Eupolybothrus Verhoeff, 1907 comprises ca. 40 valid and doubtful species and subspecies. All species are described from Eastern European and circum-Mediterranean countries, including the largest Mediterranean islands, Corsica, Crete, Cyprus, Sardinia and Sicily (
Seven subgenera were defined for the genus Eupolybothrus, based on a combination of morphological characters but these groupings remain questionable and perhaps do not reflect phylogenetic relationships (see
Currently, the subgenus Schizopolybothrus comprises nine species and subspecies, viz. Eupolybothrusacherontis (Verhoeff, 1900), E. acherontis wardaranus (Verhoeff, 1937), E. caesar (Verhoeff, 1899), E. cavernicolus Komerički & Stoev, 2013, E. excellens (Silvestri, 1894), E. leostygis (Verhoeff, 1899), E. spiniger (Latzel, 1888), E. stygis (Folkmanova, 1940), and E. tabularum (Verhoeff, 1937). Some of these are still poorly known and of uncertain taxonomic status. For example, E. spiniger, E. stygis, E. acherontis and E. acherontis wardaranus were known only from their original descriptions (see also
An integrative approach with a combination of morphological and molecular methods is certainly required to better understand the evolutionary history of this group and delineate the number of valid taxa, towards which the present work is a step.
The present work is part of an ongoing revision of the subfamily Ethopolyinae (
All specimens were collected by hand and preserved in 70% or 96% ethanol. The holotype was photographed in situ using a Canon 400D camera with a 65 mm macro objective. Microphotographs were obtained with a Nikon DS-F2.5 camera mounted on a Nikon SMZ25 stereomicroscope using NIS-Elements Microscope Imaging Software with an Extended Depth of Focus (EDF) patch. For scanning electron microscopy, parts of some specimens were cleaned with ultrasound, transferred to 96% ethanol then to acetone, air-dried, mounted on aluminum stubs, coated with Platinum/Palladium and studied in a JEOL JSM-6335F scanning electron microscope. All images were edited in Adobe Photoshop CS6 and assembled in Adobe InDesign CS6. Type material is shared between the Croatian Biospeleological Society – Croatian Natural History Museum (
Morphological terminology follows
The standard DNA barcoding locus, the Folmer-fragment of the cytochrome c oxidase subunit I (COI) gene was sequenced to delimit E. liburnicus sp. n. from other Eupolybothrus species. Mid-body legs of four specimens conserved in 70% and 96% ethanol were sent to the Canadian Centre for DNA Barcoding, Guelph, where standard protocols for DNA isolation, PCR and sequencing were performed. The analysed specimens are stored in The Barcode of Life Data System (BOLD) (
Firstly, we used the Automatic Barcode Gap Discovery (ABGD) method of
Secondly, we applied the inverse statistical parsimony (SP) method proposed by
In addition to recently collected material of a new species listed under its types below, the following material of previously named species was examined:
Eupolybothrus (Schizopolybothrus) acherontis ssp. wardaranus (Verhoeff, 1937): 1 ♂ Reg. Nr. A 200500641; 1 ♀ juv., slide preparation, Reg. Nr. A20030873, “Mazedonien: Skoplje” (
Holotype. Ad. ♂, Croatia, Obrovac, Gornji Čabrići, cave Plitka peć, under rock, 09.II.2013, A. Komerički leg.,
Paratypes. Croatia, Southern Velebit: 2 ♀, Obrovac, Gornji Čabrići, cave Plitka peć, 23.VI.2012, T. Vujnović, A. Komerički & R. Baković leg.,
A species morphologically similar to E. cavernicolus, genetically differing from it by 11% interspecific distance based on COI, and morphologically differing by the slightly convex posterior margin of T14, presence of 15CxVp and 15PDp spines, and by the leg 15 to body length ratio of ca. 64% in the adult male.
Males. Based on holotype CHP545 (light photographs) and paratype
Body length: (from anterior margin of cephalic plate to posterior margin of telson) approx. 30 mm.
Colour: tawny-brown to yellowish, ventral part and legs paler (Fig.
Head: cephalic plate slightly broader than long (3.6 × 3.1 mm, respectively) and wider than T1 (Fig.
Ocelli: 1+14 blackish irregular ocelli in 3-4 rows; outermost first seriate ocellus largest; ocelli of the middle two rows medium-sized, those of inferior row smallest (Fig.
Tömösváry’s organ: moderately large (as large as a medium ocellus), oval and situated on a sub-triangular sclerotisation below the inferiormost row of seriate ocelli.
Clypeus: showing a cluster of 25 setae situated on the apex and near the lateral margins (Fig.
Antennae: ca. 19.8 mm long, ultimate and penultimate articles of same length (Fig.
Forcipular segment (Figs
Tergites: T1 wider than long, subtrapeziform, wider anteriorly, posterior margin straight or slightly emarginated, marginal ridge with a small median thickening; TT3 and 5 more elongated than T1, posterior margin slightly emarginated medially, posterior angles rounded; posterior angles of T4 rounded; posterior margin of T8 slightly emarginated medially, angles rounded; TT6 and 7 with posterior angles abruptly rounded (Fig.
Legs: leg 15 ca. 64% body length; leg 14 approx. 25% longer than legs 1-12, leg 13 only slightly longer than legs 1-12; pretarsus of legs 1–14 with stouter posterior accessory claw (approx. as long as fundus) and a slightly thinner anterior accessory claw (= spine, sensu
Coxal pores: generally round, arranged in 6-7 irregular rows, pores of inner rows largest, size decreasing outwards; pores separated from each other by a distance more than or equal to their diameter; number of pores on leg-pair (measured on right leg) 12: 51, 13: 61, 14: 15: 44 (Fig.
Sternites: smooth, subtrapeziform, with few sparse setae, mainly at lateral margins; posterior margins straight.
Eupolybothrus liburnicus sp. n., male paratype
Genitalia: posterior margin of male first genital sternite concave, posterior margin densely covered with long setae, the rest of sternite sparsely covered with shorter ones (Fig.
Plectrotaxy: as in Table
Description of the female, based on paratype
Body length: ca. 43 mm; leg 15 ca. 22.8 mm or 52.9% body length.
Colour: uniformly tawny-brown to yellowish.
Head: cephalic plate broader than long (4 × 3.7 mm, respectively).
Ocelli: 18 blackish subequal ocelli in 6–7 rows.
Tömösváry’s organ: moderately large (as large as or slightly larger than a medium ocellus), oval, situated slightly above the cephalic edge below the inferiormost row of ocelli.
Clypeus: with a cluster of ca. 25 trichoid setae situated on the apex and lateral margins.
Antennae: approx. 18.5 mm long, composed of 73 articles.
Forcipular segment: coxosternite subpentagonal, shoulders almost absent, lateral margins straight; anterior margin set off as a rim by furrow; coxosternal teeth 9+8.
Eupolybothrus liburnicus sp. n. plectrotaxy. C – Coxa, Tr – trochanter, P – prefemur, F – femur, T – tibia, a, m, p spines in respectively, anterior, medial and posterior position.
++ | Ventral | Dorsal | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
C | Tr | P | F | T | C | Tr | P | F | T | |
1 | amp | amp | amp | amp | a-p | a-p | ||||
2 | amp | amp | amp | amp | a-p | a-p | ||||
3 | amp | amp | amp | amp | a-p | a-p | ||||
4 | amp | amp | amp | amp | a-p | a-p | ||||
5 | amp | amp | amp | amp | a-p | a-p | ||||
6 | amp | amp | amp | amp | a-p | a-p | ||||
7 | amp | amp | amp | amp | a-p | a-p | ||||
8 | amp | amp | amp | a | amp | a-p | a-p | |||
9 | amp | amp | amp | a | amp | a-p | a-p | |||
10 | amp | amp | amp | a | amp | a-p | a-p | |||
11 | amp | amp | amp | a | amp | a-p | a-p | |||
12 | m | amp | amp | amp | a | amp | a-p | a-p | ||
13 | m | amp | amp | amp | a | amp | a-p | a-p | ||
14 | am | m | amp | am | a | a | amp | p | a-p | |
15 | amp | m | amp | amp | a | a | amp | p | p |
Tergites: T1 wider than long, subtrapeziform, wider anteriorly, posterior margin straight or slightly emarginated, marginal ridge with a small median thickening; TT3 and 5 more elongated than T1, posterior margin slightly emarginated medially, posterior angles rounded; posterior angles of T4 rounded; posterior margin of T8 slightly emarginated medially, angles rounded; TT6 and 7 with posterior angles abruptly rounded; TT9, 11, 13 with well-developed posterior triangular projections; posterior margin of TT10 and 12 slightly emarginated, that of T14 transverse, all with scarce setae on posterior margin; intermediate tergite hexagonal, posterior margin slightly concave, lateral edges setose, its surface with scattered setae in a few rows located on the lateral margins and the posterior half (Fig.
Legs: leg 15 longest ca. 22.8 mm, 53% of body length; leg 14 ca. 17 mm, leg 13 ca. 10.6 mm only slightly longer than legs 1–12, midbody leg (ca. 10 mm); pretarsus of legs 1–14 with a more expanded fundus, larger posterior accessory claw (approx. 1/3rd of fundus) and a slightly thinner and shorter anterior accessory claw; pectinal (seriate) setae lacking on tarsi 1 and 2 of leg 15, present in one short row on tarsus 2 of leg 14, and in one row on tarsus 1 and two rows on tarsus 2 of legs 1-13; pretarsus of leg 15 without accessory spines. Leg 15 slender and elongate, without particular modifications.
Coxal pores: generally round, forming 6-7 irregular rows, pores of inner rows largest, size decreasing outwards; pores separated from each other by a distance more than or equal to their own diameter (Fig.
Sternites: smooth, subtrapeziform, with few sparse setae, mainly at lateral margins; posterior margins straight.
Female gonopods: densely setose, with 2+2 long, slim and pointed spurs slightly bent and a single blunt claw; outer spur 1.5 longer than the inner one, approx. 5 times longer than broad at base (Fig.
Liburnicus denotes „of Liburnia“, a district in the coastal region of the northeastern Adriatic; adjective.
The proximal knob on the male prefemur is substantially smaller in immature males than in mature specimens. For example, CHP544 (body length 11.6 mm) has the prefemoral knob represented by only a low swelling that lacks setae (Fig.
E. liburnicus sp. n. is here recorded from five caves of the Velebit Mountain, Croatia. Four of these (Plitka peć, Skorupuša, Rašljekovac and Bundalova pećina) are situated in the area where the southern slopes of the Crnopac Massif meet the Krupa River canyon while one of them, Markova špilja, is a small anchialine cave situated a few hundred meters from the Adriatic coast near the village of Seline.
The type locality is Plitka peć (Fig.
Lithobus spiniger Latzel, 1888: 93.
Lectotype. adult ♂, Bosnia and Herzegovina, 1887, J. Karlinski leg.,
(translated from Latin). ‘Robust, slightly punctate to smooth, posteriorly granulate, chestnut to reddish-brown; glossy. Two antennae slightly elongate, with 50-56 articles. Ocelli on each side: 16-19 (1 + 4, 4, 4, 3 - 1 + 4, 5, 5, 3, 1), in 4-5 longitudinal rows. Forcipular coxosternum: with 14-22 short teeth (7 + 7 - 11 + 11). Tergites 9, 11, 13 with posterior pointed projections, 14 with irregular margin, gradually narrowing posteriad in two pointed projections; coxal pores numerous, round, placed in irregular rows. Ultimate legs: elongate and robust with simple claw; spines: 1, 1, 4, 2, 0-1, coxa with 3 spines on lateral margins. In male ultimate legs, third article (femur) with a large protuberance anteriorly, and indented internal margins. Female: 28-35 mm long, 3.5-4 mm broad.’
Specimen with broken antenna; 15th legs detached, missing terminal articles, left legs 1, 3, 5 and part of the left forcipule missing.
Body length: (from anterior margin of cephalic plate to posterior margin of telson) ca. 33 mm.
Colour: reddish brown, head and first tergite darker.
Head: cephalic plate slightly broader than long (3.5 × 3.8 mm, respectively) and wider than T1 (Fig.
Ocelli: 18, blackish, in 4 irregular rows; outermost first seriate ocellus largest; ocelli of the middle two rows medium-sized, those of inferior row smallest.
Tömösváry’s organ: moderately large (as large as a medium ocellus), oval and situated on a sub-triangular sclerotisation below the inferiormost row of seriate ocelli.
Clypeus: showing a cluster of 30 setae situated on the apex and near the lateral margins (Fig.
Antennae: Broken, with more than 54 articles.
Forcipular segment: Coxosternum with 9+9 teeth and a porodont situated lateral of the distalmost tooth on both sides (Fig.
Eupolybothrus spiniger Latzel 1889, lectotype
Tergites: T1 wider than long, subtrapeziform, wider anteriorly (Fig.
Legs: leg 15 18.4 mm long, ca. 56% of body length; pectinal (seriate) setae missing on tarsus1 and 2 of leg 15, present in one short row on tarsus 2 of leg 14, in one row on tarsus 1 and two rows on tarsus 2 of legs 1-13 (Fig.
Coxal pores: generally round, arranged in 6-7 irregular rows, pores of inner rows largest, size decreasing outwards; pores separated from each other by a distance more than, or equal to their diameter (Fig.
Sternites: smooth, subtrapeziform, with few sparse setae, mainly at lateral margins; posterior margins straight.
Genitalia: posterior margin of male first genital sternite concave, broadly V-shaped, posterior margin densely covered with long setae, the rest of sternite sparsely covered with shorter setae (Fig.
E. spiniger has not been collected since Latzel’s original description. The type material consists of two syntypes – an adult male and a juvenile - collected in Foča (a town within Republika Srpska, coordinates: 43°30'N, 18°47'E) at approximately 1000 m altitude (
Comparison of standard taxonomic characters in six species of Eupolybothrus subgenus Schizopolybothrus.
E. liburnicus sp. n. | E. leostygis | E. caesar | L. spiniger | E. cavernicolus | E. wardaranus | |||
---|---|---|---|---|---|---|---|---|
Holotype | Lectotype | Syntype male | ||||||
(CHP545) | (NHMW1463) | (Nr. A 200500641) | ||||||
Body length (mm) | 30 | 33–40 | 24.1 – 31,6 | 33 | 22.6–30 | 29.2 | ||
Head | Cephalic plate | L/W (mm) | 3.1/3.6 | 3.3–4.6/3.0–3.8 | 2.4–3.7/2.4–3.8 | 3.5/3.8 | 3.6/4.0 | 2/2.5 |
Antennae | Articles L-R | 61–57 | 73–78 | 51–58 | >54 | >61–71 | 80 | |
Length | 19.8 | 19.8–28.3 (min) | 16,5 | broken | 20,0–24,0 | 10.4 | ||
Ocelli | number | 15 | 6–7 | 18–22 | R 18 | 1+14 | 18–20 | |
rows | 3 | 1–2 | 4 | 4 | 4 | 4 | ||
Coxosternum | teeth | 7+8 | 9+10 - 11+10 | 7+8 - 9+9 | 9+9 | 8+8 | 10+11 | |
setae/side | 36 | 32–48 | 26–30 | broken | 22–35 | Ca. 27 | ||
Clypeus | setae | 25 | 20–35 | 20–21 | cca 30 | 25–30 | 25 | |
Coxal pores number/rows | 12th coxa | pores/rows | 51/6 | 41–48/5–6 | 31–34/4–6 | 44/7 | 33–36/4–5 | 62/6–7 (right) |
13th coxa | pores/rows | 61/6 | 51/6–7 | 43–56/5–6 | 53/7–8 | 41–44/4–5 | 55/75–6 (right) | |
14th coxa | pores/rows | 67/7 | 59–72/6–7 | 52–70/5–6 | 60/7–8 | 49–52/4–5 | 74/6–7 (right) | |
15th coxa | pores/rows | 44/6 | 49–71/5–6 | 40–48/5–6 | 37/6 | 34–39/4–5 | 55/5–6 (right) | |
Ultimate legs | Coxa | L/W (mm) | 1/0.5 | 1.0–1.3/0.4–0.5 | 0.7–1.0/0.3–0.5 | 1/0.5 | 1.0–1.5/0.3–0.5 | 1.07/0.5 |
Prefemur | L/W (mm) | 2.7/0.8 | 3.3–4.3/0.7–0.9 | 2.3–3.0/0.6–0.8 | 3.6/0.7 | 2.4–3.7/0.8 | 1.87/0.5 | |
Femur | L/W (mm) | 3/0.6 | 5.0–6.4/0.7 | 2.6–3.7/0.5–0.7 | 3.4/0.7 | 3.4–4.0 | 2.1/0.4 | |
Tibia | L/W (mm) | 5.3/0.6 | 6.0–7.8/0.5–0.7 | 3.0–4.4/0.5–0.7 | 4.3/0.7 | 4.3–5.2 | 2.37/0.3 | |
Tarsus 1 | L/W (mm) | 4.8/0.5 | 5.3–7.9/0.3–0.5 | 2.8–4.3/0.5 | 3.9/0.4 | 3.8–5.0 | 2.69/0.3 | |
Tarsus 2 | L/W (mm) | 2.3/0.4 | 3.2–4.8/0.2–0.4 | 2.4–2.8–0.4 | 1.9/0.3 | 2.4–3.0 | 1.57/0.2 | |
Pretarsus | L/W (mm) | 0.2 | 0.4–0.6 | 0.3–0.4 | 0.3 | 0.25–0.4 | 0.3 | |
Antenna/body (%) | Ca. 66 | >70 | Ca. 52 | – | Ca. 75–80 | Ca. 3 | ||
Ultimate leg length | 19.3 | 23.2 – 33.1 | 13.6 – 19.6 | 18.4 | 22.5 | 11.9 | ||
Ultimate legs/body length | Ca. 64% | Ca. 75% | Ca. 58% | Ca. 56% | Ca. 74% | Ca. 37% | ||
Setae on intermediate tergite | Concentrated on posterior margin and on sides of median membranous area, two distinct subtriangular bare fields laterally. | Posterior margin completely covered with dense setae extending anteriad | Concentrated on posterior margin, rare setation, without visible bare fields | Present, concentrated on posterior margin | Wide area of posterior margin completely covered with dense setae, two distinct roundish bare fields laterally. | Concentrated on posterior margin, more setose medially |
Eupolybothrus acherontis wardaranus Verhoeff, 1937: 100.
Syntypes. 1 ♂ Reg. Nr. A 200500641; 1 ♀ juv., slide preparation, Reg. Nr. A20030873, “Mazedonien: Skoplje” (
Body length: (from anterior margin of cephalic plate to posterior margin of telson) approx. 29.2 mm.
Colour: uniform, yellowish brown.
Head: cephalic plate slightly broader than long (2 × 2.5 mm, respectively) and wider than T1; surface smooth, with scattered setae. Cephalic median sulcus contributing to biconvex anterior margin, marginal ridge with a median thickening; posterior margin straight to slightly concave; transverse suture situated at about 1/3rd of anterior edge; posterior limbs of transverse suture visible, connecting basal antennal article with anterior part of the ocellar area.
Ocelli: 18–20, pale, in 4 irregular rows; outermost first seriate ocellus largest; ocelli of the middle two rows medium-sized, those of inferior row smallest.
Tömösváry’s organ: moderately large (as large as a medium ocellus), oval and situated on a sub-triangular sclerotisation below the inferiormost row of seriate ocelli.
Clypeus: showing a cluster of ca. 25 setae situated on the apex and near the lateral margins.
Antennae: 10.4 mm, with 80 (left) and 79 (right) articles.
Forcipular segment: Coxosternum with 11+10 teeth and a porodont situated lateral of the distalmost tooth.
Tergites: T1 wider than long, subtrapeziform, wider anteriorly, posterior margin slightly emarginated, marginal ridge with a small median thickening; TT3 and 5 more elongated than T1, posterior margin slightly emarginated medially, posterior angles rounded; posterior angles of T4 rounded; posterior margin of T8 slightly emarginated medially, angles rounded; TT6 and 7 with posterior angles abruptly rounded; TT9, 11, 13 with well-developed posterior triangular projections; posterior margin of TT10 and 12 slightly emarginated and 14 almost straight (Fig.
Legs: leg 15 10.9 mm long, ca. 37% of body length; pectinal (seriate) setae missing on tarsus 1 and 2 of leg 15, present in one short row on tarsus 2 of leg 14, in one row on tarsus 1 and two rows on tarsus 2 of legs 1-13. Tibia with two ventral spines (Fig.
Coxal pores: generally round, arranged in 5 irregular rows, pores of inner rows largest, size decreasing outwards; pores separated from each other by a distance more than, or equal to their diameter.
Sternites: smooth, subtrapeziform, with few sparse setae, mainly at lateral margins; posterior margins straight.
Genitalia: posterior margin of male first genital sternite concave, broadly V-shaped, posterior margin densely covered with long setae, the rest of sternite sparsely covered with shorter setae. Gonopod not depicted.
Description of the syntype ♀, based on the slide A20030873 (
Clypeus: with a cluster of ca. 30 setae situated on the apex, near the lateral margins and smaller one scatted over the surface (Fig.
Forcipular segment: Coxosternum with 8+9 teeth and a porodont situated lateral of the distalmost tooth (Fig.
Female gonopods: densely setose, with 2+2 long and pointed spurs slightly bent and a single claw; outer spur 1.5 times longer than the inner one (Fig.
Although originally described as a subspecies of E. acherontis, both the nominate subspecies as well as E. acherontis wardaranus have subsequently been suspected to be junior synonyms of E. caesar (
The taxonomy of the subgenus Schizopolybothrus remains unsolved though it has been recently discussed on two occasions (
Prefemur of male leg 15 and intermediate tergite, dorsal view. A Eupolybothrus caesar, syntype B E. excellens C E. leostygis D E. tabularum E E. spiniger, lectotype F E. wardaranus G E. cavernicolus, male holotype H E. liburnicus sp. n., male holotype. (Figs B and D after
Morphological descriptions of species of the genus Eupolybothrus have traditionally relied on a number of standard external characters broadly used in lithobiomorph taxonomy (
Focusing on the species attributed to the subgenus Schizopolybothrus, we additionally examined the arrangement of setae on the 14th and intermediate tergite and the shape of its posterior margin in males as well as the presence of lateral setae-free areas (e.g. Figs
The sexual modification on leg 15 in males in Schizopolybothrus was very likely first recorded by
The presence of ‘a knob’ or a swelling on the proximal prefemur of the ultimate legs was first mentioned by
Modifications on male ultimate prefemur in Eupolybothrus species of the subgenus Schizopolybothrus.
E. wardaranus | E. caesar | E. cavernicolus | E. excellens | E. leostygis | E. liburnicus sp. n. | E. spiniger | E. tabularum | |
---|---|---|---|---|---|---|---|---|
Proximal knob | Subangular, densely setose with thin scattered setae | Round, densely setose (median setae longest) accompanied by a more proximal dorsomedial swelling | Round, protruding mediad, bearing a dorsal tuft of dense setae. | With two protruding densely setose processes | Round, with a subapical whirl of setae (median setae longest) | Round, protruding mediad, bearing a dorsal tuft of dense setae. | Subangular, with probable apical tuft of setae indicated by sockets. | Absent |
Ridge | Thin, gently narrowing towards the distal third of the prefemur | Even in width, parallel to the prefemur mesal margin | Broad, gently narrowing towards the distal third of the prefemur | Short (less than half length of prefemur), largest proximally, abruptly narrowing | Uniformly broad, narrowing only at the distal third of the prefemur | Broad, gradually narrowing at the distal half of the prefemur | Thin, gently narrowing towards the distal third of the prefemur | Absent |
Circular protuberance | Absent | Present (small), flat | Present (large), bulged | ? | Absent | Present (large), bulged | Present | ? |
The new species, Eupolybothrus liburnicus sp. n., is morphologically and genetically closest to E. cavernicolus (Tables
An unusual character depicted and described by
The four sequenced specimens of Eupolybothrus liburnicus sp. n. provided a full length DNA barcode (BOLD IDs: EUCR048-11, EUCR052-11, EUCR067-11 and EUCR068-11). The final dataset for species delimitation (our four new sequences + sequences of
Overview of interspecific K2P-genetic distances of Eupolybothrus species.
E. gloriastygis | E. leostygis | E. obrovensis | E. cavernicolus | E. litoralis | E. fasciatus | E. tridentinus GER1 | E. tridentinus GER2 | E. transsylvanicus | E. kahfi | E. nudicornis | E. grossipes | E. liburnicus sp. n. | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
E. gloriastygisBOLD:AAY5019 | |||||||||||||
E. leostygisBOLD:AAY5071 | 16.7–17.8 | ||||||||||||
E. obrovensisBOLD:AAY5641 | 16.2–17.0 | 18.5–19.4 | |||||||||||
E. cavernicolusBOLD:AAY4900 | 17.6–18.0 | 14.5–15.4 | 20.8–21.2 | ||||||||||
E. litoralis | 14.7–15.1 | 17.1–17.5 | 17.1–17.3 | 18.0–18.1 | |||||||||
E. fasciatus | 16.3–16.8 | 18.7–19.2 | 17.5–17.7 | 21.9–22.1 | 13.7 | ||||||||
E. tridentinus GER1 BOLD:AAV7132 | 17.7–18.0 | 16.7–17.3 | 18.3–18.5 | 17.4–17.7 | 18.0 | 18.3 | |||||||
E. tridentinus GER2 BOLD:AAV7131 | 17.4–17.8 | 18.6–19.1 | 19.4–19.7 | 18.1–18.4 | 15.7 | 17.5 | 10.7 | ||||||
E. transsylvanicusBOLD:AAJ0488 | 20.4–21.3 | 20.7–21.6 | 21.4–22.1 | 20.6–20.7 | 16.0–16.4 | 20.4–20.8 | 18.1 | 19.7–20.1 | |||||
E. kahfiBOLD:AAY2955 | 21.9–22.5 | 18.9–20.1 | 21.6–21.8 | 20.0–20.2 | 21.0 | 21.7 | 22.3 | 21.5 | 23.2–23.6 | ||||
E. nudicornisBOLD:AAN2808 BOLD:AAN2810 BOLD:AAN2811 | 20.1–23.2 | 19.4–21.8 | 21.1–24.1 | 21.2–22.7 | 20.1–21.7 | 21.7–22.6 | 20.7–22.4 | 19.4–21.0 | 21.4–22.3 | 17.2–18.8 | |||
E. grossipesBOLD:AAY7960 | 19.2–19.6 | 21.0–21.9 | 20.9–21.1 | 24.2–24.5 | 16.6 | 15.3 | 20.9 | 18.9 | 20.3 | 22.1 | 20.7–22.1 | ||
E. liburnicus sp. n. | 16.4–17.7 | 15.0–16.4 | 19.8–20.6 | 11.0–11.7 | 16.6–17.1 | 18.7–19.3 | 16.1–16.4 | 16.6–17.2 | 20.0–20.5 | 17.4–17.7 | 19.5–20.2 | 20.3–21.0 |
Although only three species of E. (Schizopolybothrus) were available for sequencing, they are observed to unite as a monophyletic group (moderate bootstrap support of 65), with E. leostygis being sister group to E. cavernicolus and E. liburnicus. This reconstructed topology would be consistent with a single origin of the prefemoral knob, its associated mesial ridge and the posterior circular setose protuberance in the males of these species.
Elongation of antennae and legs and reduction of pigment and ocelli are considered morphological adaptations of centipedes to the cave environment (
A number of characters indicative of troglomorphism were noted for the cave dwelling species among those studied herein in contrast to the surface dwelling ones. For instance, E. caesar shows the highest number of ocelli (22), the lowest number of antennal articles (51) and setae on coxosternum (26-30), the shortest ultimate leg podomeres (femur, tibia, tarsus 1 respectively 2.6; 3.0; 2.8) and the lowest ratio of ultimate leg to body length (52%). In contrast, E. leostygis is characterized by only (6-7) feebly pigmented ocelli (lowest in the subgenus), the longest antenna and ultimate leg podomeres, with the highest ratio of ultimate leg to body length (75%). E. cavernicolus and E. liburnicus sp. n., display some troglomorphic traits although they are probably not troglobitic, and should be considered as troglophiles. Both species have not been found outside caves although the surrounding areas were thoroughly investigated.
In 2010 and 2012, biospeleological investigations of the caves around Trebinje were conducted by one of us (AK) with the help of cavers from the Caving Club ‘Zelena brda’, which has led to the location of the following: 1) cave Iljina pećina, type locality of E. stygis and 2) cave Provalija or ‘Acheron-schlund’ (
Note. E. stygis is based on the description provided by Folkmanova (1940). E. acherontis is excluded from the key.
1 | Leg 15 prefemoral knob absent | E. tabularum |
– | Leg 15 prefemoral knob present | 2 |
2 | Prefemoral knob apically incised, forming two rounded, densely setose processes | E. excellens |
– | Prefemoral knob not incised | 3 |
3 | Posterior edge of T14 deeply emarginated, with sub-triangular posterior processes | E. spiniger |
– | Posterior edge of T14 slightly emarginated to straight | 4 |
4 | Prefemoral knob with scattered setae | 5 |
– | Prefemoral knob with specific setation (rim or tuft) | 6 |
5 | Prefemoral knob subangular, projections on leg 14 absent | E. wardaranus |
– | Prefemoral knob round, projections on leg 14 present | E. caesar |
6 | Prefemoral knob with rim of setae, six poorly defined and feebly pigmented ocelli | E. leostygis |
– | Prefemoral knob with apical tuft of setae, more than ten pronounced ocelli | 7 |
7 | 10+11 coxosternal teeth, ca. 84 antennal articles | E. stygis |
– | 7+7-8+8(9+8) coxosternal teeth, 73 or fewer antennal articles | 8 |
8 | T14 emarginated, 15CxVp and 15PDp absent | E. cavernicolus |
– | T14 slightly convex to straight, 15CxVp and 15PDp present | E. liburnicus |
The authors are grateful to the Biology Students Association BIUS of University of Zagreb for collecting valuable specimens for this study, as well as members of Caving Club Samobor and Croatian Biospeleological Society for help with field research and collecting. We are grateful to Ivan Tuf (Palacky University), Jason Dunlop (ZMB), Jörg Spelda (