Thalassaphorura, Bagnall, 1949

Kaprus’, Igor & Paśnik, Grzegorz, 2017, New Siberian “ spineless ” species of Thalassaphorura Bagnall, 1949 (Collembola, Onychiuridae), with a key to world species of the genus, Zootaxa 4362 (2), pp. 225-245 : 240-243

Key to Thalassaphorura species of the world

1. Neither anal spines nor spiniform chaetae present on Abd. VI ( Fig. 51 )........................................... 2

- Anal spines or spiniform chaetae present on Abd. VI ( Figs 45–50 ).............................................. 10

2. AIIIO with four papillae ( Figs 3 , 33 )...................................................................... 3

- AIIIO with five papillae ( Figs 17 , 26 , 40 )................................................................... 5

3. Th. tergum I with 2+2 pso, VT chaetae as 0+0/6+6/1+1 (see Sun et al. 2010), formula of dorsal pso: 32/233/33343, formula of ventral pso: 11/000/0100.... T. cryptopyga ( Denis, 1931) sensu Najt & Weiner, 1997 ); Neotropics, Pacific islands, Indonesia

- Th. tergum I with 1+1 or without pso, VT chaetae as 1+1/6+6/2+2............................................... 4

4. Formula of dorsal pso: 32/021/33343 ( Fig. 31 ), Abd sterna I–IV without pso ( Fig. 37 ), formula of modified chaetae of MVO: 0,4 l,3 l,4 l,0,0 ( Fig. 37 )............................................... T. stepensis sp. nov.; Russia: Southern Siberia

- Formula of dorsal pso: 32/122/33343 ( Fig. 1 ), Abd. sterna I–IV with 0 110 pso respectively ( Fig. 8 ), formula of modified chae- tae of MVO: 0,4 l,3 l,2 l,0,0 ( Fig. 8 )..................................... T. aspinata sp. nov.; Russia: Southern Siberia

5. Th. tergum I without pso or with 1+1 pso................................................................... 6

- Th. tergum I with 2+2 or 3+3 pso......................................................................... 8

6. Formula of dorsal pso: 32/122/33343 ( Fig. 38 ), subcoxa 1 of legs I–III with 2, 2 and 2 pso respectively, MVO present, formula of modified chaetae: 0,4l,4l,0,0,2–4l ( Fig. 44 )............................. T. weineri sp. nov.; Russia: Southern Siberia

- Formula of dorsal pso: 32/022/33343 ( Figs 9 , 16 ), subcoxa 1 of legs I–III with 1, 1 and 1 pso respectively, MVO absent.... 7

7. Pso formula on Abd. sterna I–IV: 0 111 ( Fig. 23 ), subcoxae 1 of first pair of legs with 3 chaetae ( Fig. 16 ).................................................................................. T. sibirica sp. nov.; Russia: Southern Siberia

- Pso formula on Abd. sterna I–IV: 0 110 ( Fig. 15 ), subcoxae 1 of first pair of legs with 2 chaetae ( Fig. 9 )................................................................................... T. sayana sp. nov.; Russia: Southern Siberia

8. Th. tergum I with 3+3 pso (formula of dorsal pso: 42/333/33332), VT with 4+4 distal chaetae...................................................................................... T. hoguei (Palacios-Vargas & Diaz, 1996) ; Mexico

- Th. tergum I with 2+2 pso (formula of dorsal pso: 32/233/33343), VT with 6+6 distal chaetae......................... 9

9. Pso formula on Abd. sterna I–IV: 0 112, subcoxae 1 of legs I, II and III with 4, 4, 4 chaetae respectively, MVO absent.............................................................................. T. franzi ( Stach, 1946) ; Austria, Italy

- Pso formula on Abd. sterna I–IV: 0 111 ( Fig. 30 ), subcoxae 1 of legs I, II and III with 3, 3, 3 chaetae respectively ( Fig. 24 ), MVO present, formula of modified chaetae: 0,4 l,4 l,0,0,4 l ( Fig. 30 ).......... T. stebaevae sp. nov.; Russia: Southern Siberia

10. Spiniform chaetae present on Abd VI ( Figs 49, 50 ), pseudocellar formula dorsally: 32/233/33343 and ventrally: 11/000/0112, subcoxae1 of legs I, II and III with 2, 2, 2 pso respectively................................................................................................ T. tovtrensis (Kaprus’ & Weiner, 1994); Ukraine, European part of Russia

- Anal spines present on Abd VI ( Figs 45–48 )............................................................... 11

11. AIIIO with four papillae............................................................................... 12

- AIIIO with five papillae............................................................................... 15

12. Th. tergum I without pso, posterior cephalic pso 3+3 (pso formula dorsally: 33/033/333(4)43 and ventrally without pso), sub- coxae 1 of legs I, II and III without pso............................... T. biquaternata Sun & Li, 2015 (2015b) ; China

- Th. tergum I with pso, posterior cephalic pso 2+2........................................................... 13

13. Th. tergum I with 2+2 pso, Abd. tergum IV with 4+4 pso (pso formula dorsally: 32/233/33343, pso formula ventrally: 11/000/ 0112), Abd. VI with two median chaetae a0 and m0........................ T. xihuensis Sun & Li, 2015 (2015a) ; China

- Th. tergum I with 1+1 pso, Abd. tergum IV with 3+3 pso..................................................... 14

14. Formula of dorsal pso: 32/122/22332, ventrally on head 1+1 pso present in anteromedial position, Th. tergum I with 5+5 chae- tae................................................................. T. butrosi ( Christiansen, 1956) ; Lebanon

- Formula of dorsal pso: 32/11(3)1(2)/22(3)2(3)2(3)3, ventrally on head 2+2 pso present, Th. tergum I with 6+6 chaetae......................................................... T. moniezi ( Bagnall, 1935) sensu ( Salmon 1959) ; Great Britain

15. Antennal base with four pso............................................................................ 16

- Antennal base with three pso........................................................................... 17

16. Formula of dorsal pso: 43(4)/233/44454 and ventral pso: 11/000/1112, subcoxae 1 of legs I, II and III with 2,2,2 pso respec- tively............................................... T. halophila ( Bagnall, 1937) sensu Fjellberg 1998 ; Palearctic

- Formula of dorsal pso: 42/233/33333 and ventral pso: 10/000/0112, subcoxae 1 of legs I, II and III with 1,1,1 pso respectively....................................................................... T. tamurai (Yue & Yin, 2000) ; China

17. Posterior cephalic pso 3+3 (formula of dorsal pso: 33/022/33343), PAO with 32 vesicles, size of body 1.7– 2 mm,........................................................ T. alborufescens ( Vogler, 1895) sensu Gisin (1957) ; Western Europe

- Posterior cephalic pso 2+2............................................................................. 18

18. Th. tergum I without pso............................................................................... 19

- Th. tergum I with pso................................................................................. 22

19. Th. terga II and III without pso (formula of dorsal pso: 32/000/32332), unguiculus equals 0.5 inner edge of unguis, Abd. VI with two median chaetae a0 and m0............................ T. lagunensis ( Palacios-Vargas & Diaz, 1995) ; Mexico

- Th. terga II and III with 3+3 or 2+2 pso each, unguiculus at least as long as inner edge of unguis, Abd. VI with median chaetae m0................................................................................................ 20

20. Th. terga II and III with 3+3 pso (formula of dorsal pso: 32/033/33333), formula of ventral pso: 11/000/0001, distal tibiotarsal whorl with 7 chaetae, VT chaetae as 0+0/5–6+5–6/0+0................................... T. lolae Arbea, 2017 ; Spain

- Th. terga II and III with 2+2 pso each..................................................................... 21

21. Formula of dorsal pso: 32/022/33332, PAO with 30–38 vesicles.............. T. kirgisica ( Martynova, 1971) ; Kyrghyzstan

- Formula of dorsal pso: 32/022/22223, PAO with 20–22 vesicles................. T. bagnalli ( Salmon, 1959) ; Great Britain

22. Th. tergum I with 1+1 pso.............................................................................. 23

- Th. tergum I with 2+2 pso.............................................................................. 32

23. Th. terga II and III with 2+2 pso each (pso formula on Abd. terga I–V: 33343).................................... 24

- Th. terga II and III with 3+3 pso each..................................................................... 26

24. Subcoxae1 of legs I, II and III with 1,1,1 pso respectively, VT with 1+1 anterior chaetae; Abd. ventral pso formula 11/000/ 0 100......................................................... T. reducta Sun, Chen & Deharveng, 2010 ; China

- Subcoxae1 of legs I, II and III with 2, 2, 2 pso respectively, VT without anterior chaetae, Abd. ventral pso formula another. 25

25. Abd. VI with two median chaetae a0 and m0, 3+3 axial chaetae on Abd. terga I–III, 3+3 chaetae between posterior inner pso on head, unguiculus equals 0.4 inner edge of unguis and with inner basal lamella................................................................................................... T. bapen Sun, Chen & Deharveng, 2010 ; China

- Abd. VI with one median chaetae m0, 2+2 axial chaetae on Abd. terga I–III, 4+4 chaetae between posterior pso on head, basal chaetae on ventral tube as 2+2, unguiculus equals 0.7 inner edge of unguis and without inner basal lamella............................................................................ T. guangdongensis Sun & Li, 2015 (2015a) ; China

26. Chaetae d0 absent on head............................................................................. 27

- Chaetae d0 present on head............................................................................. 28

27. Abd. sternum IV with 2+2 pso (pso formula on Abd. sterna I–IV: 0112), pso formula on Abd. terga I–V: 33334, subcoxae1 of legs I, II and III with 1,1,1 pso respectively........................ T. jailolonis ( Yoshii & Suhardjono, 1992) ; Indonesia

- Abd. sternum IV without pso or 1+1 pso (pso formula on Abd. sterna I–IV: 0001), pso formula on Abd. terga I–V: 33343, subcoxae1 of legs I, II and III with 2,2,2 pso respectively............. T. problematica Sun, Deharveng & Wu, 2013 ; China

28. Distal tibiotarsal whorl with 7 chaetae, pso formula ventrally: 10/000/0112, subcoxae1 of legs I, II and III with 1,1,1 pso respectively....................................... T. petaloides ( Rusek, 1981) ; Irak, New Caledonia, Hawaii, China

- Distal tibiotarsal whorl with 9 chaetae, ventral pso formula another............................................. 29

29. Subcoxae1 of legs I, II and III with 2, 2, 2 pso respectively, VT without anterior chaetae, pso formula on Abd. sterna I–IV: 0 111.......................................................... T. grandis Sun, Chen & Deharveng, 2010 ; China

- Subcoxae1 of legs I, II and III with 1, 1, 1 pso respectively, VT with 1+1 anterior chaetae, pso formula on Abd. sterna I–IV another............................................................................................. 30

30. Abd. sternum IV without pso (ventral pso formula: 11/000/0000), labial papillae of AC type....................................................................... T. thalassophila ( Bagnall,1937) after Sun et al., 2010; Northern Europe

- Abd. sternum IV with 1+1 or 2+2 pso.................................................................... 31

31. Formula of ventral pso: 11/000/0001, pso formula on Abd. terga I–V: 33343, Abd. VI with one median chaetae a0, unguiculus reduced to small blunt process..................................... T. brevisetosa Sun, Gao & Potapov, 2014 ; China

- Formula of ventral pso: 11/000/0001(2), pso formula on Abd. terga I–V: 3,3–4,3,4–6,3–4, Abd. VI with two median chaetae a0 and m0, unguiculus equals 0.5 inner edge of unguis.......................................................................................... T. debilis ( Moniez, 1890) after Sun et al., 2010, (form a); Western and northern Europe

32. Abd. tergum IV with 3+3 pso (formula of dorsal pso: 32/233/33333)............................................ 33

- Abd. tergum IV with more than 3+3 pso................................................................... 37

33. PAO with about 45 vesicles, Abd. tergum I with 9+9 chaetae, AS equals 0.4 unguis, formula of modified chaetae of MVO: 14 s,0,0,0,0,0................................................................ T. ishikawai ( Yosii, 1956) ; Japan

- PAO with not more than 30 vesicles, Abd tergum I with less chaetae, AS more than 0.7 length of unguis............... 34

34. Unguiculus with basal lamella, approximately as long as inner edge of unguis, VT chaetae as 1+1/6+6/1+1..................................................................................... T. guineaensis ( Salmon, 1965) ; Guinea

- Unguiculus without basal lamella, approximately equals 0.7 of inner edge of unguis................................ 35

35. Abd. sternum IV without pso (formula of ventral pso: 11/000/1120), Th. tergum I with 7+7 chaetae, VT chaetae as 1+1/6+6/ 2+2............................................................... T. yodai ( Yosii, 1966) ; Nepal, China, Japan

- Abd. sternum IV with 2+2 pso, Th. tergum I with less chaetae................................................. 36

36. Formula of ventral pso: 10/000/1112, subcoxae1 of legs I, II and III with 2,2,2 pso respectively, chaetae on VT as 0+0/6+6/2+2...................................................................... T. yolandae ( Izarra, 1971) ; Venezuella

- Formula of ventral pso: 10/000/0112, subcoxae1 of legs I, II and III with 1,2,2 pso respectively, VT chaetae as 1+1/5+5/2– 3+2–3................................................................. T. tamdaona ( Nguyen, 1995) ; Vietnam

37. Abd. tergum V with 2+2 pso,........................................................................... 38

- Abd. tergum V with 3+3 or 4+4 pso...................................................................... 39

38. Formula of ventral pso: 11/000/0001, formula of dorsal pso: 32/233/3333(4)2, AS equals 0.5 unguis............................................................................................... H. orientalis ( Stach, 1964); China

- Formula of ventral pso: 10/111/0000, formula of dorsal pso: 32/233/33342, AS equals 0.7 unguis................................................................................................ T. ghatensis ( Prabhoo, 1971) ; India

39. Subcoxae 1 of legs I, II and III with 1,1,1 pso respectively, formula of dorsal pso: 32/233/3,3–4,3,4–6,3–4, formula of ventral pso: 11/000/0111(2)......................... T. debilis ( Moniez, 1890) after Sun et al., 2010, (form b); Northern Europe

- Subcoxae 1 of legs I, II and III with 2(1),2,2 pso respectively, formula of dorsal pso: 32/233/33343.................... 40

40. Abd. sternum IV with 1+1 pso.......................................................................... 41

- Abd. sternum IV with 2+2 pso.......................................................................... 43

41. Formula of ventral pso: 11/000/0001, Abd. VI with two median chaetae a0 and m0, unguiculus equals 0.3 of inner edge of unguis....................................... T. sensilata ( Thibaud & Massoud, 1979) ; Caribbean Islands , Mexico

- Formula of ventral pso: 11/000/0111..................................................................... 42

42. Th. tergum I with 5+5 chaetae, Abd. VI with one median chaetae a0, chaetae on VT as 1+1/6+6/1+1, AS equals 0.2 unguis.............................................................. T. pomorskii Sun, Chen & Deharveng, 2010 ; China

- Th. tergum I with 7–8+7–8 chaetae, Abd. VI with one median chaetae m0, chaetae on VT as 1+1/6–8+6–8/2+2, AS equals 0.7 unguis..................... T. duplopunctata ( Strenzke, 1954) after Sun et al. (2013); Holarctic (arctic and boreal areas)

43. Ventrally on head 1+1 pso present, ungiuculus less than 0.2 of inner edge of unguis, AS equals 0.9 unguis................................................................................... T. thaibinhensis ( Nguyen, 2001) ; Vietnam

- Ventrally on head 2+2 pso present, ungiuculus equals or bigger than 0.5 of inner edge of unguis...................... 44

44. Distal tibiotarsal whorl with 7 chaetae, ungiuculus equal 0.5 of inner edge of unguis, with basal lamella, AS equals 0.7 unguis.......................................................... T. tibiotarsalis Sun, Chen & Deharveng, 2010 ; China

- Distal tibiotarsal whorl with 9 chaetae.................................................................... 45

45. Abd. sternum I with 1+1 pso (pso formula on Abd. sterna I–IV: 1112), Th. tergum I with 7+7 chaetae, ungiuculus equals 0.7 of inner edge of unguis, without basal lamella, Abd. VI with one median chaetae m0... T. kwona ( Thibaud & Lee, 1994) ; Korea

- Abd. sternum I without pso............................................................................. 46

46. Dorsally on head 3+3 chaetae between two posterior inner pso ( Fig. 1 ).......................................... 47

- Dorsally on head 4+4 chaetae between two posterior inner pso................................................. 56

47. Th. tergum I with 5+5 chaetae........................................................................... 48

- Th. tergum I with more than 5+5 chaetae.................................................................. 51

48. Abd. VI with two median chaetae a0 and m0............................................................... 49

- Abd. VI with one median chaetae a0..................................................................... 50

49. Ungiuculus with inner basal lamella, AS equals unguis on distinct papillae, S-chaetae differentiated, their formula dorsally: 11/ 0 1 1/ 221120 ...................................................... T. tiani Sun, Chen & Deharveng, 2010 ; China

- Unguiculus without inner basal lamella, AS equals 0.6 unguis on indistinct papillae, S-chaetae not differentiated............................................................................ T. linzhiensis Sun & Li, 2015 (2015a) ; China

50. AS equals 0.7 unguis, S-chaetae on body not differentiated, size of body 0.9–1.4 mm.......................................................................... T. zschokkei ( Handschin, 1919) sensu Pomorski, 1998 ; Europe, Israel, Iran

- AS equals 0.3 unguis, S-chaetae on body differentiated, size of body 0.6–0.8 mm................................................................................................... T. hainamica Sun, Gao & Potapov, 2014 ; China

51. Abd. VI with two median chaetae a0 and m0............................................................... 52

- Abd. VI with one median chaetae a0 or m0................................................................ 55

52. Th. tergum I with 6+6 chaetae........................................................................... 53

- Th. tergum I with 7(8)+7(8) chaetae...................................................................... 54

53. Chaetae on VT as 0+0/6–7+6–7/0+0, 7 labial proximal chaetae present, inner basal lamella on unguiculus absent, body size 1.2–1.7, formula of modified chaetae of: 0,6–12 l,7–10 l,0,0,0.................. T. qixiaensis Yan, Shi & Chen, 2006 ; China

- Chaetae on VT as 1+1/7+7/2+2, 6 labial proximal chaetae present, inner basal lamella on unguiculus present, body size 0.6– 0.85, formula of modified chaetae of MVO: 2 ih,0,0,0,0,0.............................. T. petiti Sun & Wu, 2013 ; China

54. Labial type AC, inner basal lamella on unguiculus absent, Abd. tergum IV without median chaetae, S-chaetae on body differentiated, formula of modified chaetae of MVO: 2 ih,0,0,0,0,0......................... T. bisetosa Sun & Wu, 2013 ; China

- Labial type A, inner basal lamella on unguiculus present, Abd. tergum IV with median chaetae m0, S-chaetae on body not differentiated, males unknown (parthenogenetic species)...... T. encarpata ( Denis, 1931) sensu Fjellberg, 1998 ; Cosmopolitan

55. AS equals 0.4 unguis, VT with 5+5 distal chaetae, Abd. VI with one median chaetae a0, MVO absent.................. T............................................................... tenuis Babenko, 2007 ; Russia (Middle Siberia)

- AS equals 1.1 unguis, VT with 6+6 distal chaetae, Abd. VI with one median chaetae m0, formula of modified chaetae of MVO: 5 st,0,0,0,0,0...................................... T. macrospinata Sun & Wu, 2012 ; China, Russia (Far East)

56. Th. tergum I with 5+5 chaetae, chaetae on VT as 1+1/6+6/2+2, AS equals 0.5 unguis, MVO absent....................................................................... T. lifouensis ( Thibaud & Weiner, 1997) ; New Caledonia, China

- Th. tergum I with 7(8)+7(8) chaetae, chaetae on VT as 1+1/7+7/2+2, AS equals 0.9–1.0 unguis, formula of modified chaetae of MVO: 2 ih,0,0,0,0,0................................................... T. qinlingensis Sun & Wu, 2013 ; China

Figures

FIGURES45–52. Chaetotaxy of Abd. tergum VI (dorsal and lateral view): 45‒46, Thalassaphorura macrospinata Sun & Wu, 2012 from Russia (Far East); 47‒48, Thalassaphorura zschokkei (Handschin,1919) from Iran; 49‒50, Thalassaphorura tovtrensis (Kaprus’ & Weiner, 1994) from Ukraine; 51, Thalassaphorura aspinata sp. nov.: chaetotaxy of Abd. tergum V and VI; 52, Thalassaphorura sibirica sp. nov.: chaetotaxy of labium.

FIGURES 1–8. Thalassaphorura aspinata sp. nov.: 1, habitus and dorsal chaetotaxy; 2, dorsal side of Ant. III and IV; 3, AIIIO; 4, PAO and anterior cephalic pso; 5, tibiotarsal chaetotaxy and claw of leg III; 6, chaetotaxy of anal valves; 7, shape of S-chaetaeand modified chaetae of MVO(a‒‒Th.tergaII‒III,b‒‒Sl chaetaonAbd.terga I‒III,c‒‒Sp chaetaon Abd.tergum V, d‒‒modified chaetae of MVO); 8, chaetotaxy of Abd.sterna I‒VI.

FIGURES31–37. Thalassaphorura stepensissp.nov.: 31, habitus and dorsalchaetotaxy;32,dorsal side of Ant.III and IV; 33, AIIIO; 34, PAO and anterior cephalic pso; 35, tibiotarsal chaetotaxy and claw of leg III; 36, shape of S-chaetae and modified chaetaeof MVO (a‒‒Th.terga II‒III, b‒‒Sl chaetaonAbd.terga I‒III, c‒‒Sp chaetaon Abd.tergumV, d‒‒modified chaetaeof MVO); 37, chaetotaxy of Abd.sterna II‒VI.

FIGURES 16–23. Thalassaphorura sibirica sp. nov: 16, habitus and dorsal chaetotaxy; 17, dorsal side of Ant. III and IV; 18, sensory rods and sensory clubs of AIIIO; 19, maxillary palp, 20, PAO and anterior cephalic pso; 21, tibiotarsal chaetotaxy and claw of leg III; 22, shape of S-chaetae (a‒‒Th. terga II‒III, b‒‒Sl chaeta on Abd. terga I‒III, c‒‒Sp chaeta on Abd. tergum V); 23, chaetotaxy of Abd.sterna I‒VI.

FIGURES 24–30. Thalassaphorura stebaevae sp. nov.: 24, habitus and dorsal chaetotaxy; 25, dorsal side of Ant. III and IV; 26, AIIIO; 27, PAO and anterior cephalic pso; 28, tibiotarsal chaetotaxy and claw of leg III; 29, shape of S-chaetae and modified chaetae of MVO (a‒‒Th.terga II‒III, b‒‒Sl chaeta on Abd.terga I‒III, c‒‒Sp chaeta on Abd. tergum V, d‒‒modified chaetae of MVO on Abd. sterna II and III, e‒‒modified chaetae of MVO on Abd. sternum VI); 30, chaetotaxy of Abd. sterna II‒VI.

FIGURES 38–44. Thalassaphorura weineri sp. nov.: 38, habitus and dorsal chaetotaxy; 39, dorsal side of Ant. III and IV; 40, AIIIO; 41, PAO and anterior cephalic pso; 42, tibiotarsal chaetotaxy and claw of leg III; 43, shape of S-chaetae and modified chaetaeof MVO (a‒‒Th.terga II‒III, b‒‒Sl chaetaonAbd.terga I‒III, c‒‒Sp chaetaon Abd.tergumV, d‒‒modified chaetaeof MVO); 44, chaetotaxy of Abd.sterna II‒VI.

FIGURES 9–15. Thalassaphorura sayana sp. nov.: 9, habitus and dorsal chaetotaxy; 10, dorsal side of Ant. III and IV; 11, chaetotaxy of labium; 12, Ptibiotarsal chaetotaxy and claw of leg III; 13, PAO and anterior cephalic psoI; 14, shape of Schaetae (a‒‒Th. terga II‒III, b‒‒Sl chaeta on Abd. terga I‒III, c‒‒Sp chaeta on Abd. tergum V, d‒‒S chaeta on Abd. tergum VI); 15, chaetotaxy of Abd. sterna I‒VI.