ZOOTAXA

ISSN 1175-5326 (print edition)

ISSN 1175-5334 (online edition)Copyright © 2014 Magnolia Press

Zootaxa 3835 (3): 381–391

www.mapress.com/zootaxa/ Correspondencehttp://dx.doi.org/10.11646/zootaxa.3835.3.8

http://zoobank.org/urn:lsid:zoobank.org:pub:16FC0C9F-F6FC-41E9-BE60-79250B4B4D49

Redefinition of the genus Argonychiurus Bagnall, 1949 (Collembola,

Onychiuridae) with description of a new species from Georgia

REVAZ DJANASHVILI1, SHALVA BARJADZE1,4, RAFAEL JORDANA2 & ULRICH BURKHARDT3

1Institute of Entomology, Agricultural University of Georgia, 13th km. of David Aghmashenebeli Alley, 0159, Tbilisi, Georgia 2Museum of Zoology, University of Navarra, Irunlarrea 1, 31008 Pamplona, Navarra, Spain3Senckenberg Museum of Natural History, P. O. Box 300154, 02806, Görlitz, Germany 4Corresponding author

The genus Argonychiurus was established by Bagnall (1949) based on the type species Onychiurus perforatus

Handschin, 1920. He included Onychiurus bertrandi Denis, 1936 in this newly erected genus, together with O.

perforatus.

Here, members of the genus Argonychiurus were characterized by granulated (morel-like) sensory clubs on

Ant III O, a PAO consisting of compound vesicles, chaeta d0 absent, posterior pso on the head present, indistinct

sensory chaetae s, a reduced furca present as a very small area with 1+1 chaetae posteriorly and two manubrial

rows of chaetae, Abd VI tergum with three rows of chaetae and unpaired median chaetae present, absence of anal

spines, and multiplied pso pattern (Bagnall 1949, Weiner 1996).

The following three species are listed in the genus Argonychiurus: A. bertrandi (Denis, 1936), A. fistulosus

(Gisin, 1956) and A. perforatus (Handschin, 1920) (Bagnall 1949, Weiner 1996). So far, species of this genus are

known only from Europe. Type material of Onychiurus lenticularius Gisin, 1962 and Onychiurus papulosus Gisin,

1964 was investigated by second and fourth authors and it was found that the above mentioned species in most

characters correspond morphologically to the genus Argonychiurus, e.g., by presence of compound vesicles in

PAO, posterior pso on the head, indistinct sensory chaetae s, the furca reduced to a small finely granulated area

with 1+1 chaetae posteriorly in one row, Abd VI tergum with three rows of chaetae and unpaired median chaetae,

absence of anal spines, and multiplied pso pattern. However, O. lenticularius and O. papulosus have a d0 chaeta

present and O. lenticularius has smooth sensory clubs with two ribs in Ant III O. The presence of d0 chaeta and

smooth ribbed sensory clubs was not included in the diagnoses of the genus Argonychiurus by Bagnall (1949) and

Weiner (1996). Diagosis of the genus Argonychiurus is redefined and new combinations for O. lenticularius and O.

papulosus (Gisin, 1962) are suggested to include them in this genus as Argonychiurus lenticularius (Gisin, 1962)

comb. nov. and A. papulosus (Gisin, 1964) comb. nov.

Besides, as a result of the study of specimens collected by the first author, a new species of Argonychiurus

from a Georgian cave is described.

Abbreviations. Abd I–VI—abdominal segments I–VI respectively, Th II–III—thoracic segments II–III

respectively, Ant I–IV—antennal segments, Ant III O—antennal III sensory organ, Cl I–III—claws of tibiotarsi I,

II and III respectively, Emp—empodium, am—anterior manubrial row of chaetae, mm––medial manubrial row of

chaetae, ms––microsensillum, PAO—postantenal organ, pso—pseudocellus(-i), psx—parapseudocellus(-i), s-

chaeta––sensory chaeta s, Tita—tibiotarsus(-i), VT—ventral tube.

The numbering of chaeta in text and figures follows Cassagnau (1974) and Fjellberg (1999).

Argonychiurus Bagnall, 1949

Type species: Onychiurus perforatus Handschin, 1920: 22

Diagnosis. Argonychiurus species have granulated (morel-like) or smooth sensory clubs with ribs on Ant III O; a

PAO consisting of compound vesicles; type A of labial papillae; chaeta d0 on the head present or absent; posterior

Accepted by W.M. Weiner: 9 Jun 2014; published: 11 Jul. 2014 381

pso on the head present, indistinct sensory chaetae s; Tita with 11 chaetae in distal whorl; a reduced furca as a small

finely granulated area with 1+1 chaetae posteriorly and two or three manubrial rows of chaetae; Abd VI tergum

with three rows of chaetae and unpaired median chaetae present; absence of anal spines and multiplied pso pattern.

Discussion. We added to the diagnostic characters of the genus Argonychurus the granulation of sensory clubs

in Ant III O, as present in A. lenticularius comb. nov., which has smooth sensory clubs with ribs and three rows of

manubrial chaetae, as present in the new species. Absence of d0 chaeta on the head was observed in A. fistulosus,

while A. lenticularius comb. nov., A. papulosus comb. nov. and the new species described below do have a d0

chaeta, indicating that the presence or absence of the d0 chaeta on the head is not a constant character throughout

this genus, as mentioned also by Anatoly Babenko (pers. com.). Character–multiplication of pso on the whole body

was suggested as a generic character by Bagnall (1949)

Onychiurus bogheani Gruia, 1989 has been assigned to the genus Argonychiurus by several authors (e.g. Fiera

2007). However, as this species shows no tendency of multiplication of pso but a constant dorsal pseudocellar

formula, we did not include it into the genus Argonychiurus.

Argonychiurus multiocellatus sp. nov.

Figs 1–14, Table 1

Type material. Holotype: female, Georgia, Tsageri district, Khvamli mountainous massif, Tvishi cave

[42°30'55.09"N, 42°47'35.96"E], 446 m alt.,12.ix.1968, leg. Revaz Djanashvili. Code number MZ–19680912–1

(H–090). Holotype deposited at the Museum of Zoology, University of Navarra, Pamplona, Spain. Paratypes: 5

females and one juvenile, same data as holotype, each on different slides; a paratype, code number

MZ–19680912–2, is deposited at the Museum of Zoology, University of Navarra, Pamplona, Spain, and 5

paratypes with code numbers GC19680912–3 to 7 are deposited at the Institute of Entomology of Agricultural

University of Georgia, Tbilisi, Georgia.

TABLE 1. Argonychiurus multiocellatus sp. nov. Variability of number of dorsal pso for 5 specimens.

MZ–19681112–1 MZ–19681112–2 GC–19681112–3 GC–19681112–4. GC–19681112–5.

Ant bases 3+3 5+4 4+4 4+4 4+4

On PAO level 2+2

+1(unpaired anterior)

2+2 2+2 2+2

+1(unpaired

anterior)

2+2

+2 (central

asymmetric)

middle part of

head

2+4 3+3 3+3 2+3 4+3

posterior part of

head

5+5 dorsal

3+4 interseg.

12 dorsal

? interseg.

8 dorsal

9 interseg.

6 dorsal

? interseg.

8 dorsal

9 interseg.

Th I 7+8 tergal

1+1interseg.

9 tergal

6 interseg.

10 tergal

9 interseg.

8 tergal

4 interseg.

7+7 tergal

4 interseg.

Th II 14+18 tergal

5+7 interseg.

11 tergal

9 interseg.

15 +15 tergal

5+3 interseg.

14 tergal

6 interseg.

14+14 tergal

16 interseg.

Th III 12+16 tergal

4+3 interseg

9 tergal

7 interseg.

15 tergal

17 interseg.

13 tergal

10 interseg

18 tergal

18 interseg.

Abd I 11+9 tergal

4+5 interseg.

11 tergal

7 interseg.

16 tergal

16 interseg

12 tergal

3 interseg

12+12 tergal

8 interseg

Abd II 10+11 tergal

6+5 interseg

11 tergal

6 interseg

18 tergal

18 interseg

9+5 tergal

7 interseg

11+11 tergal

11 interseg

Abd III 15+16 tergal

0 interseg

13 tergal

? interseg

14 tergal

15 interseg

8+8 tergal

11 interseg

13+13 tergal

0 interseg

Abd IV 15+16 tergal

0 interseg

11+10 tergal

0 interseg

19+16 tergal

0 interseg

8+7 tergal

0 interseg

9+9 tergal

10 interseg

Abd V 7+7 tergal

0 interseg

15+15 tergal

0 interseg

8+8 tergal

0 interseg

9+9 tergal

0 interseg

16 tergal

8 interseg

DJANASHVILI ET AL.382 · Zootaxa 3835 (3) © 2014 Magnolia Press

Description. Colour white in alcohol. Length of females without antennae: 1.78–2.69 mm. Body cylindrical,

little broadened in the region of Abd II–IV (Fig. 12). Antennae 0.73–0.99 times as long as head diagonal.

Granulation uniform and slightly coarse on dorsal part of head, antennal base not marked.

Ant IV: subapical organite not guarded by papillae, ms in proximal whorl of chaetae (above Ant III O), ms on

Ant III slightly below Ant III O (Figs 3–4). Ant III O with 5 papillae, 5 guard chaetae, 2 sensory rods and 2 bent,

morel-like, sensory clubs (Figs 4–5). Labium with 2 proximal, 2 basomedian (E, F, G, and f) and 6 basolateral (a, b,

c, d, e, e’) chaetae (Fig. 6); Postlabial chaetae 4+4 along ventral groove. Labial palp (Fig. 6) with papilla A of 3.9

µm wide at its base, with slight sudden narrowing at 30 µm of base. Papilla A a little wider and shorter than B, D

and E. Measurements: A= 45, B = 60, C= 35, D = 55 and E = 50 (all in µm). Clypeal/prelabral/labral chaetae: 2 /4 /

3, 4, 2 labral (Fig. 7).

PAO small, with 10–12 granulated vesicles (Fig. 2). Ratio between PAO length and diameter of its closest pso

= 3:1.

Dorsal pseudocellar formula per whole tergum (Ant base, interantennal zone, PAO level, middle part, posterior

part / Th I, Th II, Th III / Abd I, Abd II, Abd III, Abd IV, Abd V): 6–9, 0–2, 4, 5–7, 6–17/12–19, 20–44, 16–36/

15–32, 17–36, 13–31, 15–35, 14–30 (Ant base with 3–5 pso each) (Table 1, Figs 1–2); pso formula ventrally for

each half sternum: 0/000/3–6, 8–9, 6–8, 7–9, 3–5; Subcoxae 1 of legs I–III with 8–14, 7–12, 8–14, pso

respectively; subcoxae 2 of legs I–III with 0, 3–5, 3–5 pso respectively (Fig. 9). Psx absent.

On Th II–III and Abd I–V pso are arranged in two more or less visible rows.

Dorsal chaetotaxy more or less asymmetric, poorly differentiated into macro-, meso- and microchaetae.

Chaetae s indistinct. Th II–III with lateral microsensilla within a shallow pit. Chaeta d0 on the head present (Fig. 1),

Th. sterna I–III with 1+1, 1+1, 1+1 chaetae respectively, VT with 2+2 basal and 10–13+10–13 distal chaetae (Fig.

11). Cl I–III without teeth; Tita with 11 chaetae in distal whorl. Emp I–III with small basal lamella, slightly shorter

than Cl (Fig. 10). Furcal area reduced to a small finely granulated area with 1+1 chaetae posteriorly (Figs. 13–14).

Furcal zone with a finely granulated area and two microchaetae below. The finely granulated area is clearly

visible in paratype GC–19681112–3 (Fig. 14a); in holotype (Figs 13, 14b) the finely granulated area is hidden in a

fold, but in it and in all paratypes two microchaetae are present. These two dental chaetae have 3 rows of manubrial

chaetae (ma, mm and mp).

Abd VI tergum with 3 rows of chaetae, a0 and p

0 chaeta present. Anal spines absent (Fig. 12).

Discussion. In this new species, the dorsal pso formulae given above are very variable due to asymmetries, the

intersegments have numerous pso, and in most cases the specimens are artificially shortened due to ‘telescoping’

artifacts and folding of intersegments under the posterior edges of head or thoracic and abdominal terga, in which

cases the pso are difficult to see and to separate tergal and intersegmental pso from each other. The new species

shares with A. fistulosus (Gisin, 1956) the presence of pso on the medio-dorsal area of the head (Gisin 1956). It

differs from A. fistulosus by the number of pso at the antennal base (3–5+3–5 in A. multiocellatus sp. nov. v. 2+2 in

A. fistulosus), by presence of chaeta d0 on the head in A. multiocellatus sp. nov. (absent in A. fistulosus), absence of

pso on the head ventrally in A. multiocellatus sp. nov. (vs. 1+1 pso present in A. fistulosus), the absence of an inner

tooth on Cl I–III in A. multiocellatus sp. nov., while a distinct inner tooth is present on Cl I–III in A. fistulosus. A.

bertrandi, A. lenticularius comb. nov., A. papulosus comb. nov. and A. perforatus differ from of the new species

by the absence of pso in the medio-dorsal area of the head. The new species differs from A. lenticularius comb.

nov. by the shape of its sensory clubs in Ant III O, which are granulated (morel–like) as in all Argonychiurus

species except A. lenticularius comb. nov., which has smooth clubs with 2 ribs.

Etymology. The new species name is derived from the Latin names multi (numerous) and ocellus (small eye),

which is suitable for this new species with its distinct morphological character, the multiplication of pseudocelli.

Ecology. A. multiocellatus is found in the aphotic zone of caves. So far it is only known from Georgia.

A key to the species of the genus Argonychiurus Bagnall, 1949

1 Pso on the mediodorsal area of the head present . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

– Pso on the mediodorsal area of the head absent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Antennal base with no more than 2+2 pso; chaeta d0 absent; pseudocellar formula ventrally: 1/000/33341 . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. fistulosus (Gisin, 1956)

Zootaxa 3835 (3) © 2014 Magnolia Press · 383A NEW COLLEMBOLA FROM GEORGIAN CAVE

– Antennal base with 3–5 pso; chaeta d0 present; pseudocellar formula ventrally: 0/000/3–6, 8–9, 6–8, 7–9, 3–5 . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. multiocellatus sp. nov.

3 Sensory clubs of Ant III O are smooth with ribs . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. lenticularius (Gisin, 1962) comb. nov.

– Sensory clubs of Ant III O are granulated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

4 Antennal base with 3–4 + 3–4 pso; pseudocellar formula ventrally: 0/000/23330 . . . . . . . . . . . . . . A. bertrandi (Denis, 1936)

– Antennal base with 2+2 pso; pseudocellar formula ventrally different . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5 Pseudocellar formula ventrally: 0/000/33130 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. papulosus (Gisin, 1964) comb. nov.

– Pseudocellar formula ventrally: 1/000/6, 9, 5–6, 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. perforatus (Handschin, 1920)

Acknowledgements

We thank Dr Peter Schwendinger (Muséum d’ Histoire Naturelle, Geneva, Switzerland) for loan of the type

material of Argonychiurus fistulosus (Gisin, 1956), O. lenticularius Gisin, 1962 and O. papulosus Gisin, 1964.

The second author was supported by German Academic Exchange Service (DAAD) program: “Research Stay

for University Academics and Scientists” (ref. A/11/05439) to work at the Senckenberg Museum of Natural

History, Görlitz, Germany, and by Shota Rustaveli National Science Foundation (SRNSF) program: “Internships

abroad for young scientists” (ref. 24/06) to work at University of Navarra, Pamplona, Spain.

References

Bagnall, R.S. (1949) Contribution toward a knowledge of the Onychiuridae (Collembola–Onychiuroidea). V–X. Annals and

Magazine of Natural History, Series 12, 2 (19), 498–511.

http://dx.doi.org/10.1080/00222934908654001

Denis, J.R. (1936) Sur la faune française des Aptérygotes. XX. Revue française d’entomologie, 3, 142–144.

Cassagnau, P. (1974) Chétotaxie et phylogenié chez les Collemboles Poduromorphes. Pedobiologia, 14 , 300–314.

Fiera, C. (2007) Checklist of Romanian springtails (Collembola). Folia Entomologica Hungarica, 68, 5–40.

Fjellberg, A. (1999) The labial palp in Collembola. Zoologischer Anzeiger, 237, 309–330.

Gisin, H. (1956) Nouvelles contributions au démembrement des espèces d’Onychiurus (Collembola). Bulletin de la Société

Entomologique Suisse, 29, 329–352.

Gisin, H. (1962) Sur la faune européenne des Collemboles IV. Revue Suisse de Zoologie, 69, 1–23.

Gisin, H. (1964) Collemboles d’Europe. VI. Revue Suisse de Zoologie, 71, 383–400.

Gruia, M. (1989) Nouvelles espèces troglobiontes des collemboles de Roumanie. Miscellanea Speologica Romanica, 1,

103–111.

Handschin, E. (1920) Die Onychiurinen der Schweiz. Verhandlungen der Naturforschenden Gesellschaft in Basel, 32, 1–37.

Weiner, W.M. (1996) Generic revision of Onychiuridae (Collembola: Onychiuridae) with a cladistic analysis. Annales de la

Société Entomologique de France (Nouvelle Série), 32, 163–200.

DJANASHVILI ET AL.384 · Zootaxa 3835 (3) © 2014 Magnolia Press

FIGURES 1–2. 1, Argonychiurus multiocellatus sp. nov. (holotype). 1, chaetotaxy and localization of pso on head and Th

tergum I. a = Antennal base; b = interantennal zone; c = PAO zone; d = central zone; e = Posterior zone; 2, detail of antennal

base. Scale bars: for 1 = 50 µm, for 2 = 20 µm.

Zootaxa 3835 (3) © 2014 Magnolia Press · 385A NEW COLLEMBOLA FROM GEORGIAN CAVE

FIGURES 3–5. Argonychiurus multiocellatus sp. nov. (holotype). 3, dorsolateral view of Ant.; 4, ventrolateral view of Ant.; 5,

sensorial club of AIIIO, 5a surface level view, 5b, middle level slice, 5c, deeper level. Scale bars: for 3–4 = 50 µm, for 5 = 8

µm.

DJANASHVILI ET AL.386 · Zootaxa 3835 (3) © 2014 Magnolia Press

FIGURES 6–7. Argonychiurus multiocellatus sp. nov. (paratype Gc–19681112–7). 6, labial chaetotaxy and labial palps; 7,

clypeal, prelabral and labral chaetotaxy. Scale bars: for 6 = 50 µm, for 7 = 20 µm.

Zootaxa 3835 (3) © 2014 Magnolia Press · 387A NEW COLLEMBOLA FROM GEORGIAN CAVE

FIGURE 8. Argonychiurus multiocellatus sp. nov. (holotype). Chaetotaxy and localization of pso on Th terga I–III. Scale bar

= 50 µm.

DJANASHVILI ET AL.388 · Zootaxa 3835 (3) © 2014 Magnolia Press

FIGURES 9–11. Argonychiurus multiocellatus sp. nov. 9, localization of pso on subcoxae 1 and 2 of I–III legs; 10, claw and

empodium; 11, VT. Scale bars: for 9 = 200 µm, for 10–11 = 50 µm.

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FIGURE 12. Argonychiurus multiocellatus sp. nov. (holotype). Chaetotaxy and localization of pso on Abd terga I-VI. Scale

bar = 50 µm.

DJANASHVILI ET AL.390 · Zootaxa 3835 (3) © 2014 Magnolia Press

FIGURE 13–14. Argonychiurus multiocellatus sp. nov.: 13, chaetotaxy and localization of pso on Abd sterna III-VI

(holotype); 14a, chaetotaxy of furcal area (Paratype GC–19681112–3); 14b, chaetotaxy of furcal area of Holotype. Scale bars:

for 13 and 14b = 50 µm, for 14a = 100 µm.

Zootaxa 3835 (3) © 2014 Magnolia Press · 391A NEW COLLEMBOLA FROM GEORGIAN CAVE