Tomocerus leyensis, Yu & Deharveng, 2018

Yu, Daoyuan & Deharveng, Louis, 2018, Two new Chinese species of Tomocerus at different stages of troglomorphic adaptation (Collembola, Tomoceridae), Zootaxa 4403 (1) : -

Tomocerus leyensis sp. nov.

FIgs 1B , 4 , 5

Type material. HOLOtypE: fEMALE On sLIdE, LOuMEI DOng (cAVE), LEyE tOWn, LEyE COunty, BAIsE, GuAngxI PROVIncE, ChInA, 16.III.2002, LEg. ARthuR CLARkE (CHI-062) . PARAtypEs: 1 subAduLt On sLIdE, 2 In ALcOhOL, sAME dAtA As hOLOtypE; 2 MALEs And 1 fEMALE On sLIdEs, 11 In ALcOhOL, AI DOng (cAVE), BEIZhOng, LEyE COunty, BAIsE, GuAngxI PROVIncE, ChInA, 23–31.III.2002, LEg. ARthuR CLARkE (CHI-063, CHI-065). OnE pARAtypE dEpOsItEd In MNHN , hOLOtypE And OthER pARAtypEs In NJAU .

Description. BOdy LEngth 2.6–3.3 MM. BOdy cOLOuR LIght tO dARk gREy, AntEnnAE, LEg bAsEs And fROnt AREA Of hEAd OftEn dARkER. EyE pAtchEs bLAck ( FIg. 1B ).

TypEs Of chAEtAE sIMILAR tO thOsE Of Tomocerus troglodytes sp. nov.

COMpLEtE AntEnnAE nOt sEEn, LOngEst ObsERVEd AntEnnA (WIth fusEd Ant. III+IV) AbOut As LOng As bOdy. LEngth RAtIO Of Ant. I:II = 1.0:1.4–1.8. Ant. I And Ant. II scALEd On dORsAL sIdE, Ant. III unscALEd. PAO nOt sEEn. EyEs 6+6, sMALL. MOuthpARts nORMAL fOR Tomocerus . LAbRAL fORMuLA 4/5, 5, 4. DIstAL EdgE Of LAbRuM WIth fOuR cuRVEd spInEs. MAndIbuLAR hEAd AsyMMEtRIcAL, LEft OnE WIth 4 tEEth And RIght OnE WIth 5, LEft MOLAR pLAtE dIstALLy WIth A tApEREd tOOth. MAxILLARy LAMELLA 5 WIth shORt tEEth, WIthOut bEARd-LIkE AppEndAgE ( FIg. 4A ). MAxILLARy OutER LObE WIth tRIfuRcAtE pALp And OnE bAsAL chAEtA, subLObAL pLAtE WIth 4 hAIRs. BOth dORsAL And VEntRAL sIdEs Of hEAd scALEd. CEphALIc dORsAL MAcROchAEtOtAxy As AntERIOR AREA 2, IntEROcuLAR AREA 2, 4, cEntRAL unpAIREd MAcROchAEtA AbsEnt, pOstOcuLAR AREA 2+2, pOstERIOR AREA 2+2. POstERIOR MARgIn Of hEAd WIth AppROxIMAtELy 30+30 chAEtAE ( FIg. 4B ). MEntuM WIth fIVE chAEtAE, subMEntuM WIth nuMEROus chAEtAE.

PAttERn Of bOdy chAEtOtAxy As In FIg. 4C . BOthRIOtRIchA 2, 1/ 0, 0, 1, 2, 0, 0 On Th. II–Abd. VI. MAcROchAEtAE dEnsELy ARRAngEd ALOng AntERIOR MARgIn Of Th. II (nOt shOWn In fIguRE). Th. II WIth An IRREguLAR ROW Of MAcROchAEtAE bEhInd AntERIOR MARgIn. NuMbER Of MAcROchAEtAE OR LARgE MEsOchAEtAE In thE pOstERIOR ROW As 2, 3/ 3, 2, 3, 2, 4 fROM Th. II tO Abd. V. Th. II WIth 1 cEntRAL MAcROchAEtA; Abd. III WIth tWO AntERIOR MAcROchAEtAE; Abd. IV WIth OnE AntERO-LAtERAL MAcROchAEtA; Abd. VI WIth nuMEROus chAEtAE Of dIffEREnt sIZEs. MEsOchAEtAE MOst AbundAnt LAtERALLy And pOstERIORLy On tERgA, pAttERn nOt studIEd. PsEudOpOREs nOt cLEARLy sEEn.

TROchAntERO-fEMORAL ORgAn WIth 1, 1 sLEndER chAEtAE. TIbIOtARsI I, II And III WIth 3–4, 3–4, 5 spInE-LIkE VEntRAL chAEtAE, REspEctIVELy ( FIg. 4D ). EAch tIbIOtARsus WIth A dIstAL WhORL Of 11 chAEtAE, VEntRAL 6 As ORdInARy chAEtAE, dORsAL 5 MOdIfIEd; tEnEnt hAIR cLAVAtE On ALL LEgs, shORt And thIn, AbOut 0.3–0.5 tIMEs As LOng As InnER EdgE Of unguIs; tWO AccEssORy chAEtAE sLEndER, sLIghtLy LOngER thAn pREtARsAL chAEtAE; tWO guARd chAEtAE 1.2–1.8 tIMEs As LOng As tEnEnt hAIR, 0.55–0.6 tIMEs As LOng As InnER EdgE Of unguIs ( FIg. 4E ). UnguIs sLEndER, OutER EdgE AbOut 0.2– 0.23, 0.18–0.21, 0.15–0.17 tIMEs As LOng As OutER EdgE Of tIbIOtARsI On LEg I, II And III, REspEctIVELy ( FIg. 4D ). UnguIs WIth bAsO-IntERnAL RIdgEs AbOut 1/4–1/3 dIstAncE fROM bAsE; LAtERAL tEEth pOIntEd, Of MOdERAtE sIZE. InnER EdgE Of unguIs WIth 4–6 tEEth, bAsAL tOOth sMALL, sub-bAsAL tOOth sLIghtLy LARgER thAn dIstAL tEEth. UnguIcuLus LAncEOLAtE, AbOut 0.6–0.75 tIMEs As LOng As InnER EdgE Of unguIs, WIth 0–1 InnER tOOth. PREtARsus chAEtAE 1+1 ( FIg. 4E ).

VEntRAL tubE scALEd On bOth AntERIOR And pOstERIOR fAcEs, LAtERAL fLAps unscALEd. AntERIOR fAcE WIth AbOut 40 chAEtAE On EAch sIdE, pOstERIOR fAcE WIth AbOut 90–100 chAEtAE, EAch LAtERAL fLAp WIth AbOut 70–80 chAEtAE. RAMI Of tEnAcuLuM WIth 4+4 tEEth, AntERIOR fAcE WIth 4–6 chAEtAE And WIthOut scALEs ( FIg. 5A ). RAtIO MAnubRIuM:dEns:MucRO=2.7–3.4:3.8–4.4:1.0. MAnubRIuM VEntRALLy scALEd And WIthOut chAEtAE; LAtERALLy WIth LARgE ROund scALEs And 9–11 chAEtAE On EAch sIdE, pROxIMAL chAEtA sMALL, dIstAL OnEs stROng; dORsALLy WIth tWO LOngItudInAL chAEtAL stRIps And WIthOut scALEs, EAch chAEtAL stRIp WIth AppROxIMAtELy 150–180 chAEtAE Of dIffEREnt sIZEs, WIthOut dIstInct pROMInEnt chAEtAE; psEudOpOREs 10–15 On EAch sIdE ( FIg 5B ); MAnubRIAL dIstAL cORnER chAEtA As LARgE As MOdERAtE sIZEd MEsOchAEtAE In chAEtAL stRIp ( FIg. 5C ), OR shORtER And bIfuRcAtE ( FIg. 5D ). DEns bAsALLy WIthOut dIstInct pROMInEnt dORsAL chAEtA, LARgE MOdIfIEd InnER scALE OR stROng OutER chAEtAE. DEntAL spInE fORMuLA As 4–5/6–9, I In AduLt, 4/5, I In subAduLt; spInEs Of cOMpOund shApE, WIth nuMEROus MOdERAtE tO LARgE dEntIcLEs In MIddLE And sMALL dEntIcLEs In bAsAL And dIstAL pARt ( FIg. 5E ). DEns dORsALLy WIth ORdInARy chAEtAE And fEAthER-LIkE chAEtAE, VEntRALLy WIth dEnsE scALEs. MucRO ELOngAtEd And MuLtI-sEtAcEOus; bOth bAsAL tEEth WIth pROxIMAL LAMELLAE, OutER bAsAL tOOth WIth MOdERAtE tO LARgE sIZEd tOOthLEt; ApIcAL And subApIcAL tEEth subEquAL; stRuctuRE Of dORsAL LAMELLAE Of Tomocerus typE, tWO dORsAL LAMELLAE RunnIng fROM subApIcAL tOOth, OutER LAMELLA EndIng In InnER bAsAL tOOth, InnER LAMELLA EndIng At bAsE Of MucRO; OutER LAMELLA WIth 4–7 (2–3 In subAduLt) IntERMEdIAtE tEEth ( FIg. 5F ).

Etymology. NAMEd AftER thE typE LOcALIty LEyE COunty.

Ecology. SAMpLE CHI-062: 250 M IntO cAVE, In fLOOd dEbRIs And sOIL; sAMpLE CHI-063: 150 M IntO cAVE, undER WOOd; sAMpLE CHI-065: 500 M IntO cAVE, On OLd bAMbOO LAddERs.

Remarks. On thE bAsIs Of thE pREsEncE Of 2 MEsOthORAcIc bOthRIOtRIchA And thE shApE Of dEntAL spInEs (cOMpOund WIth nuMEROus dEntIcLEs), Tomocerus leyensis sp. nov. shOuLd bE A MEMbER Of thE ocreatus cOMpLEx. It Is sIMILAR tO thE cAVE spEcIEs T. postantennalis , T. dong , T. deharvengi And T. cthulhu In thE LOng AntEnnAE, thE gREy bOdy cOLOuR And thE WEAk tEnEnt hAIRs. But thE LAtER spEcIEs ALL hAVE LARgE PAO And tWO LARgE dIstAL dEntAL spInEs, WhEREAs thE nEW spEcIEs hAs nO dIstInct PAO And OnLy OnE LARgE dIstAL dEntAL spInE. BEsIdEs, T. leyensis sp. nov. dIffERs fROM thE LAtER spEcIEs ALsO In thE dORsAL chAEtOtAxy And In hAVIng MORE InnER tEEth On unguIs ( TAbLE 2). ThE pEcuLIAR MORphOLOgy Of bIfuRcAtE MAnubRIAL dIstAL cORnER chAEtA In tWO IndIVIduALs Of T. leyensis sp. nov. Is sO fAR unIquE AMOng knOWn spEcIEs. In OnE spEcIMEn thE tWO bRAnchEs Of thE chAEtA ARE EquAL In LEngth, WhILE In thE OthER spEcIMEn OnE bRAnch Is dIstInctLy shORtER ( FIg. 5D ).

Figures

FIGURE 1. Photographs of the species in alcohol (lateral view) (A) Tomocerus troglodytes sp. nov.; (B) Tomocerus leyensis sp. nov. with both antennae broken.Scale bars:1 mm.

FIGURE 4. Tomocerus leyensis sp. nov. (A) lamella 5 of maXillary head (dorsal view); (B) cephalic dorsal chaetotaXy (dorsal view); (C) dorsal chaetotaXy of Th. II–Abd. V (dorsal view); (D) tibiotarsus I, II and III (lateral view); (E) hind claw compleX (lateral view).Symbols as for Figure 2 and 3.

FIGURE 5. Tomocerus leyensis sp. nov. (A) tenaculum (anterior view); (B) left side of manubrium (dorsal view); (C) distal area of manubrium (dorsal view); (D) alternative forms of manubrial distal corner chaeta; (E) basal part of dens and dental spines (dorsal view); (F) left mucro (inner view).Symbols as for Figure 2 and 3.