Endonura tatricola ( Stach, 1951 )

Smolis, Adrian, 2008, Redescription of four Polish Endonura Cassagnau, 1979 (Collembola, Neanuridae, Neanurinae), with a nomenclature of the ventral chaetae of antennae, Zootaxa 1858, pp. 9-36 : 17-25

Endonura tatricola ( Stach, 1951)

Figs 1–6 , 23–39 , Tab. 2–3

Biloba tetrophtalma tatricola Stach, 1951: 35

Neanurella szeptyckii Weiner, 1973: 531 syn. nov.

Type material. Lectotype juvenile on slide by present designation, originally labelled “ Polonia Tatry”, 1933, leg. J. Stach, det. J. Stach (collection of the Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Cracow, Poland).

Stach described B. tetrophtalma tatricola on the basis of five specimens collected in three localities in the Polish part of Tatra Mts, but he did not designate the holotype. Consequently two specimens from the first marked locality are syntypes. One of them was designated here as the lectotype, the second probably has been lost (W. M. Weiner pers. comm.).

Other material. Poland, East Carpathians, Bieszczady Mts., near Komańcza village, nature reserve "Przełom Osławy pod Duszatynem", north–east slope of Karnaflów Mt., 500–600 m alt., Carpathian beech– fir forest, under bark of rotting logs, decaying wood, 30.IV–2.V.2001, leg. A. Smolis, 4 females and 10 juveniles on slides; East Carpathians, Bieszczady Mts., near Prełuki village, 450 m alt., juv., Osława valley, Carpathian alder forest, decaying wood, 2.V.2001, leg. A. Smolis, juvenile on slide; West Carpathians, Beskid Niski Mts., Magurski National Park, near Huta Polańska village, valley of Zimna Woda stream, 500 m alt., Carpathian beech forest, decaying wood, 14.VI.2001, leg. A. Smolis, male on slide; West Carpathians, Beskid Niski Mts., Magurski National Park, near Folusz village, valley of Kłopotnica stream, 500 m alt., Carpathian beech forest, decaying wood, 15.VI.2001, leg. A. Smolis, female on slide; West Carpathians, Beskid Niski Mts., nature reserve "Kornuty", 700 m alt., Carpathian beech forest, decaying wood, 15.VI.2001, leg. A. Smolis, female on slide; West Carpathians, Beskid Sądecki Mts., near Krynica, north slope of Dubne Mt., 850 m alt., Carpathian beech forest, decaying wood, 27.IV.1999, leg. A. Smolis, 3 females and male on slides; West Carpathians, Beskid Sądecki Mts., nature reserves "Łabowiec" and "Uhryń", near Łabowiec village, 800 m alt., Carpathian beech forest, decaying wood, litter, 3.V.2000, leg. A. Smolis, D. SkarŻyński, 14 females, 2 males and 3 juveniles on slides; West Carpathians, Pieniny Mts., Pieniński National Park, north–east slopes of Nowa Góra Mt., 890 m alt., Carpathian beech forest, litter, 25.viii.1971, leg. W.M. Weiner, det. W.M. Weiner, holotype (female) of Neanurella szeptyckii Weiner, 1973 on slide; West Carpathians, Pieniny Mts., Pieniński National Park, valley of Ociemny stream, 600 m alt., Carpathian beech forest, under bark of rotting log, 26.V.1994, leg. R. J. Pomorski, det. R. J. Pomorski, 7 females, 3 males and 5 juveniles on slides; West Carpathians, Pieniny Mts., Pieniński National Park, valleys of Pieniński and Huliński stream, 600–700 m alt., Carpathian beech forest, under bark of rotting logs, in decaying wood and litter, 30.IV.1999, 2.V.1999, leg A. Smolis, numerous individuals on slides; West Carpathians, Tatra Mts., Tatrzański National Park, Jaworzynka valley, 1300–1400 m alt., Norway spruce forest (subalpine belt), decaying wood, 14.VI.2000, leg. D. SkarŻyński, A. Smolis, numerous individuals on slides; Beskid Żywiecki Mts., Babiogórski National Park, north slope of Babia Góra Mt., 1000–1250 m alt., Norway spruce forest (subalpine belt), fir–spruce forest and Carpathian beech forest (montane belt), decaying wood, litter, 3–4.VI.1999, leg. A. Smolis, numerous individuals on slides; West Carpathians, Beskid Śląski Mts., near Ustroń, north–east slope of Wielka Czantoria Mt., valley of Suchy stream, 650 m alt., Carpathian beech forest, decaying wood, litter, 16.IV.2001, leg. A. Smolis, 4 females and 7 males on slides; West Carpathians, Beskid Śląski Mts., near Ustroń, valley of Sucha Dobka stream, 500 m alt., spruce forest, decaying wood, 16.IV.2001, leg. A. Smolis, female on slide. Slovakia, Slovenský Raj National Park, mixed forest, under bark of decomposed logs, decaying wood, 1.v.2000, leg. A. Smolis, 4 females, 6 males and 2 juveniles on slides. Other material (except for holotype of Neanurella szeptyckii Weiner, 1973 ) is housed in the collection of the Department of Biodiversity and Evolutionary Taxonomy, Wrocław University, Poland.

Diagnosis. Habitus typical of the genus Endonura . Dorsal tubercles present and well developed, except tubercles Di on th. I. 0–2+0–2 eyes, when present: small and unpigmented ( Figs 23 , 32 , 37 ). Buccal cone rather short. Labral chaetotaxy 4/2, 4. Mandible thin with 3 teeth. Head with 3 chaetae Oc, chaetae A, B, C and D. Chaeta O absent. Tubercles Dl and (L+So) on head wih 6 and 10 chaetae respectively. Tubercles De on thoracic terga II and III with 3 and 4 chaetae respectively. Tubercles L on abd. III and IV with 3 and 6 chaetae respectively. Abd. IV and V with 8 and 3 tubercles respectively. Claw without inner tooth. Tibiotarsi with chaetae B4 and B5 short.

Redescription. Habitus typical of the genus. Body length (without antennae): females 0.9–2.0 mm, males 0.8–1.3 mm, I instars 0.5–0.7 mm. Colour of the body white. 0–2+0–2 small unpigmented eyes ( Figs 23 , 32 , 37 ). Number of eyes variable (see: Variability).

Types of dorsal ordinary chaetae. Macrochaetae Ml thin, relatively short, straight, narrowly sheathed, gradually tapered and apically pointed ( Figs 23 , 34, 39 ); macrochaetae Mc and Mcc thin, straight, apically pointed; mesochaetae and microchaetae short, thin and pointed. Macrochaetae very similar in I instars and in adults ( Fig. 32 ). All macrochaetae feebly serrated. Number and arrangement of chaetae in adults and I instars same, except chaetotaxy of ant. IV (see: Tab. 2 c and Figs 1–6 , 28–29 ) and genital plate (complete absence of chaetae in first instars).

Head. Buccal cone short ( Figs 25 , 30 ). Labrum rounded, with ventral sclerifications as in Fig. 30 . Labrum chaetotaxy 4/2, 4 ( Fig. 25 ). Chaetotaxy of labium as in Fig. 24 . Maxilla styliform, mandible thin tridentate. Chaetotaxy of antennae in adults and I instars as in Tab. 2 c and in Figs 1–6 , 28–29 . Apical vesicle distinct, simple. Sensilla S on ant.IV subequal, short and rather thick ( Figs 1 , 28 ). Chaetotaxy of head as in Tab. 2 a, b, and Figs 23, 24 , 30, 32 , 35, 37 . Tubercles Cl and Af separate ( Figs 35, 37 ). Chaetae O and E absent. Chaetae D and L4 free ( Fig. 37 ). Tubercle Dl with 6 chaetae, chaeta Dl3 present ( Fig. 37 ). Elementary tubercle BE absent, rarely present (see: Variability, Figs 35, 37 ). Chaeta A shorter than B.

Thorax, abdomen, legs. Body sensilla fine and smooth, shorter than nearby macrochaetae ( Figs 23 , 31, 32 ). Chaetotaxy of th. and abd. as in Tab. 2 d and in Figs 23 , 31–34, 36, 38–39 . Tubercles Di on th.I not differentiated or present (see: Variability, Figs 23 , 32 ). Chaetae De3 on abd. I–III shorter than De2. Chaetae De2 on th. II–III and De3 on th. III connected with tubercle De. Chaetae De3 on abd. I–III connected with tubercle De ( Figs 23 , 31–32 ). The line of chaetae De1–sensillum perpendicular to the dorsomedian line on abd. I–IV ( Figs 23 , 33 ). Tubercle L on abd. III and IV with 3 and 6 chaetae respectively ( Fig. 36 ). One chaeta L on abd. IV free. Furca rudiment with 6–8 microchaetae, variable in size ( Fig. 38 ).Tubercles Di on abd. V fused, with chaeta Di2 as Mc, Mcc or mi ( Figs 23 , 32 , 34, 39 ). Chaeta L' on abd. V present ( Fig. 36 ). Cryptopygy absent. Chaetotaxy of legs as in Tab. 2 d and Figs 26–27 , 31 . Tibiotarsi with short chaetae B4 and B5. Claw without inner tooth ( Figs 26–27 ).

Discussion. Endonura tatricola is the most similar and closely related to E. incolorata ( Stach, 1951) and E. dudichi ( Loksa, 1967) . All mentioned species form a very distinct and peculiar group within the genus Endonura characterised by the following features: body white, eyes small and unpigmented or absent, absence of chaetae O and E on head, chaeta L4 on head freee and absence of non-reticulate areas between chaetae A and B on head. Nevertheless, they can be easily separated by the number of tubercles on abdominal segments IV and V (in tatricola 8 and 3 tubercles respectively, in incolorata 8 and 2 tubercles, in dudichi 5 and 3 tubercles). Moreover, these species differ in a presence/absence of elementary tubercle BE on head (in tatricola absent or rarely present, in incolorata absent, in dudichi present), presence/absence of tubercles Di on th. I (in tatricola absent or rarely present, in incolorata absent, in dudichi present) and the length of macrochaetae Ml (in tatricola and incolorata relatively short, in dudichi long).

Variability. The number of eyes is highly variable within Polish populations of E. tatricola and specimens with 2+2, 2+1, 1+1, 0+1 or 0+0 eyes were observed in the same population ( Tab. 3 ). Specimens from Bieszczady Mts. (Eastern Carpathians) differ from other populations in a presence of elementary tubercle BE on head and tubercles Di on th. I. The taxonomic status of this geographic polymorphism remains to be investigated.

Distribution. Up to now E. tatricola was reported from the Slovakia (Low Tatra Mts., Nosek 1964, 1969) and Polish Carpathians (Tatra Mts., Stach 1951; Pieniny Mts., as Neanurella szeptyckii, Weiner 1981 ; Beskid Sądecki Mts., Smolis & SkarŻyński 2006; Beskid Żywiecki Mts., SkarŻyński & Smolis 2006). More localities of the species from Poland and Slovakia are herein added (see: Other material). Additionaly Gruia (1974) reported this species from the Rumanian Carpathians and described a morphology of all its instars. Nevertheless, a detailed analysis of figures in the paper (see: Gruia 1974, 214: Figs 1, 4 and 217: Figs 13 , 14 ) showed that these specimens represented another genus and species, probably closely related to Neanura minuta Gisin, 1963 . Data of the occurrence of E. tatricola suggest that it is widely distributed in the Western and scattered in the Eastern Carpathians. However, its eastern and southern limits are no known precisely and needed further studies.

Ecological remarks. A mountain saproxylic species, occurs mainly in the belts of mountain forests, sporadically ( Stach 1951) in dwarf mountain-pine shrubs (subalpine belt). It prefers shady and humid forests e.g. stands of beech, fir and spruce. Found predominantly in humid rotting wood and under bark of decaying logs, but also in litter with fine woody debris. Moreover, a numerous specimens were observed on roots of a newfallen spruce (W.M. Weiner pers. comm.). First instars were collected in April, May and Jule.

Remarks. Stach (1951) described Biloba tetrophtalma tatricola on the basis of specimens collected in the Tatra Mts. (Polish Carpathians). Later in “Collembolenfauna Europas” Gisin (1960) raised this subspecies to species status. Nevertheless, Salmon (1964) and Dunger (1966) still considered it as a subspecies of Neanura tetrophtalma . Massoud (1967) again elevated this taxon to specific rank: Neanura tatricola . Cassagnau (1979) placed the species in the subgenus Endonura . Since the original description is devoid of information on variability and chaetotaxy of many parts of body I decided to make a modern redescription of the species based on all current available material.

a) Cephalic chaetotaxy–dorsal side.

b) Cephalic chaetotaxy–ventral side.

c) Chaetotaxy of antennae.

vi 4 cm 3 bs, 1 miA 3 bs, 1 miA d 5 cp 8 miA, 1 brs 8 miA d) Postcephalic chaetotaxy.

Weiner (1973) described Neanurella szeptyckii based on specimens from Pieniny Mts. (Polish Carpathians). A detailed examination of types of both mentioned species allowed to ascertain that they differed in the number of eyes only (in szeptyckii 0+0 eyes, in tatricola 2+2 eyes). In the light of the variablity of this feature observed in E. tatricola (see: Variability) E. szeptyckii is a junior synonym of the species.

Figures

FIGURES 1 – 6. Endonura tatricola: 1, dorsal chaetotaxy of ant. III – IV, adult (terminology after Deharveng 1983); 2, dorsal chaetotaxy of ant. III – IV, group d and sensilla brs; 3, chaetotaxy of AOIII, groups vi and d of ant. III; 4, ventral chaetotaxy of ant. III – IV, adult; 5, ventral chaetotaxy of ant. IV, groups va and ap; 6, ventral chaetotaxy of ant. IV, groups cm and cp.

FIGURES 23 – 27. Endonura tatricola: 23, chaetotaxy and distribution of tubercles (adult female from Tatra Mts., dorsal view); 24, chaetotaxy of labium and group Vi; 25, chaetotaxy of labrum; 26, trochanter, femur, tibiotarsus and claw III (ventrolateral view); 27, trochanter, femur, tibiotarsus and claw III (lateral view).

FIGURES 28 – 29. Endonura tatricola: 28, dorsal chaetotaxy of ant. III – IV, first instar; 29, ventral chaetotaxy of ant. III – IV, first instar.

FIGURES 30 – 33. Endonura tatricola: 30, ventral chaetotaxy of head; 31, chaetotaxy of thorax, abd. I and subcoxae 2 (lateral view); 32, chaetotaxy and distribution of tubercles (dorsal view, first instar); 33, scheme of position of sensillum and chaeta De 1 on abd. I – IV (dm –– dorsomedian line).

FIGURES 34 – 39. Endonura tatricola: 34, tubercle (Di + Di) of abd. V; 35, tubercles Af and Cl on head (specimen from Bieszczady Mts.); 36, chaetotaxy of abd. II – VI (ventrolateral view); 37, dorsal chaetotaxy of head; 38, furca rudiment; 39, tubercle (Di + Di) of abd. V.

FIGURES 9 – 13. Endonura lusatica: 9, dorsolateral chaetotaxy of head; 10, dorsal chaetotaxy of ant. III – IV; 11, tibiotarsus and claw III (ventrolateral view); 12, tibiotarsus and claw II (ventrolateral view): 13, femur, tibiotarsus and claw III (lateral view).

FIGURES 14 – 19. Endonura lusatica: 14, chaetotaxy of labium and group Vi; 15, ventral chaetotaxy of head; 16, dorsal chaetotaxy of abd. III – VI; 17, scheme of position of sensillum and chaeta De 1 on abd. I – IV (dm –– dorsomedian line); 18, ventral sclerifications of labrum; 19, chaetotaxy of labrum.

Tables

TABLE 2. Chaetotaxy of Endonura tatricola:

Tubercle	Number of chaetae	Types of chaetae	Names of chaetae
Cl	4	Ml Mc or Mcc	F G
Af	8	Ml Mc Mcc or mi mi	B A C D
Oc	3	Ml mi	Ocm, Ocp Oca
Di	2	Ml or Mc Mcc or mi	Di1 Di2
De	2	Ml Mcc or mi	De1 De2
Dl	6	Ml Mcc or mi mi	Dl1, Dl5 Dl3, Dl4 Dl2, Dl6
(L+So)	10	Ml Ml or Mc me mi	L1, So1 L4 So3–6 L2, L3, So2

TABLE 3. Variability of the number of eyes in Polish populations of Endonura tatricola from: Tatra Mts. (32 specimens), Beskid Żywiecki Mts. (36 specimens) and Pieniny Mts. (30 specimens).

Specimens Number of eyes 2+2 2+1	1+1	1+0	0+0
Tatra Mts. 25 (78,2%) 5 (15,6%) Beskid Żywiecki 17 (47,2%) 10 (27,8%) Mts.	0 (0%) 3 (8,3%)	1 (3,1%) 4 (11,1%)	1 (3,1%) 2 (5,6%)
Pieniny Mts. 3 (10%) 7 (23,3%)	7 (23,3%)	10 (33,4%)	3 (10%)