Neoribates isabelaensis, Bayartogtokh & Ermilov & Corpuz-Raros, 2017

Bayartogtokh, Badamdorj, Ermilov, Sergey G. & Corpuz-Raros, Leonila, 2017, An interesting sexually dimorphic species, Neoribates isabelaensis sp. nov. (Acari, Oribatida, Parakalummidae) with remarks on sexual dimorphism in Oripodoidea, Zootaxa 4347 (1) : -

Neoribates isabelaensis sp. nov.

( Figs 1–20 )

Diagnosis. Body size: 448–547, 282–365. NotogAster, AnogenitAl region And mediobAsAl pArt of prodorsum slightly tuberculAte. Rostrum pointed. TrAnslAmellA complete. RostrAl, lAmellAr And interlAmellAr setAe long, setiform; ro densely bArbed, le And in spArsely bArbed, le inserted Anterior to lAmellAr ends. BothridiAl setAe longest of prodorsAl setAe, setiform, bArbed. Anterior notogAstrAl mArgin conVex mediAlly. SexuAl dimorphism expressed in the structure of posterior pArt of notogAster: mAles with lArge round concAVity beAring pAir of sAcculi S 3 As opposed to normAl structure in femAles; S 3 in mAles distinctly lArger thAn in femAles. NotogAstrAl setAe short, setiform, smooth. SubcApitulAr setAe h longest, thick, heAVily bArbed, m setiform, bArbed, a setiform, bArbed in mediodistAl pArts. EpimerAl And AnogenitAl setAe setiform, thin, slightly bArbed. Four pAirs of genitAl setAe minute, setiform, smooth. AdAnAl setAe ad 3 inserted in preAnAl position. MArginoVentrAl porose AreA represented by numerous rounded And elongAte oVAl pArts. Legs tridActylous, lAterAl clAws with one tooth VentrodistAlly.

Measurements. Body length: 464 (holotype, mAle), 448–547 (18 pArAtypes, nine femAles And nine mAles); notogAster width: 298 (holotype), 282–365 (18 pArAtypes). FemAles lArger thAn mAles: 498–547, 332–365 Versus 448–464, 282–298.

Integument ( Figs 1 , 2 , 4–6 , 8 ). Body color light brown to brown. Body surfAce microfoVeolAte (Visible under high mAgnificAtion in dissected specimens, 1000). NotogAster, AnogenitAl region And mediobAsAl pArt of prodorsum slightly And spArsely tuberculAte (diAmeter of tubercles up to 4), cleArly Visible in mAles. LAterAl pArts of prodorsum (between bothridiA And AcetAbulA I, II) microgrAnulAte.

Prodorsum ( Figs 1 , 3, 5 , 17, 18 ). Rostrum pointed (well Visible in frontAl View). Lobe with A projection, creAting one inner rostrAl tooth. RostrophrAgmAtA relAtiVely thick. LAmellAe locAted dorso-lAterAlly, slightly longer thAn hAlf of prodorsum (meAsured in lAterAl View), their ends curVing AnteromediAlly And connected by strong, complete trAnslAmellA. SublAmellAe two thirds of lAmellAe. SublAmellAr porose AreAs rounded (12–16), coVered by sublAmellAe. Anterior And posterior ridges on lAterAl sides of prodorsum present, simple, distAnced from eAch other, VentrolAterAl ridges not Visible. RostrAl (65–73), lAmellAr (90–94) And interlAmellAr (98–106) setAe thickened, setiform, ro densely bArbed, directed AnteromediAd, le And in spArsely bArbed, erect, le inserted on prodorsum, Anterior to lAmellAr ends. ExobothridiAl setAe And their AlVeoli Absent. BothridiAl setAe longest of prodorsAl setAe (143–147), thickened, setiform, bArbed, directed posterolAterAd. SejugAl porose AreAs diffuse, oblong, trAnsVersely oriented. DorsophrAgmAtA represented by group of low, roughened thickenings collectiVely elongAted longitudinAlly, with VAriAble number of components.

Notogaster ( Figs 1 , 2 , 4, 5–9 , 17, 18 ). Anterior notogAstrAl mArgin conVex mediAlly. Posterior pArt of notogAster in mAles with lArge round concAVity beAring pAir of sAcculi S 3, whereAs in femAles posterior pArt of notogAster eVenly rounded. Ten pAirs of short (6–8), setiform, thin, smooth notogAstrAl setAe (c, la, lm, lp, h 1– h 3, p 1– p 3); setA lp inserted posteriorly or mediAl And close to S1, h 1 And h 2 locAted close to eAch other. Four pAirs of sAcculi with smAll openings And slightly elongAted chAnnels, Sa distAnced equAlly between c And la; S 3 in mAles distinctly lArger thAn those in femAles. All lyrifissures distinct, im locAted posterior to lm And distAnced from them, ip between p 1 And p 2, ih Anterior to p 3 And distAnced from them, ips posterolAterAl to p 3. OpisthonotAl glAnd openings locAted between im And h 3. CircumgAstric scissure And circumgAstric sigillA bAnd distinct.

Gnathosoma ( Figs 10–12 ). SubcApitulum longer thAn wide (114–123, 94–98). SubcApitulAr mentum And genAe with one pAir of longitudinAl furrows. SubcApitulAr setAe h (30–32) thick, heAVily bArbed, m (18–20) setiform, bArbed, a (14–16) setiform, bArbed in mediodistAl pArts. Two pAirs of AdorAl setAe (12–14) setiform, densely bArbed. PAlps (length 61–65) with setAtion 0–2–1–3–9(+ω). PostpAlpAl setAe (4) spiniform, slightly roughened. ChelicerAe (length 114–123) with two thickened, setiform setAe, cha (32–36) longer thAn chb (20–24). Trägårdh’s orgAn long, elongAte triAngulAr.

Epimeral and lateral podosomal regions ( Figs 2 , 5 ). EpimerAl setAl formulA: 3–1–3–3. SetAe setiform, bArbed, 3с, 4c (28–32) longer thAn 1b, 3b (24), 1a, 1c, 2a, 3a (20–24) And 4a, 4b (16). PedotectA I And II smAll, lAminA-like, Pd II rectAngulAr in VentrAl View, rounded Anteriorly. DiscidiA triAngulAr, broAdly rounded distAlly. CircumpedAl cArinAe long, reAching Anterior mArgin of VentrAl plAte.

Anogenital region ( Figs 2 , 5–9 , 19, 20 ). Four pAirs of genitAl setAe (6–8) setiform, thin, smooth. One pAir of AggenitAl (12–16), two pAirs of AnAl (10–12) And three pAirs of AdAnAl (12–16) setAe setiform, thin, slightly bArbed. SetAe ad 3 inserted in preAnAl position. AdAnAl lyrifissures locAted close And pArAllel or slightly diAgonAl to AnAl plAtes. MArginoVentrAl porose AreA represented by numerous rounded And elongAte oVAl pArts. OVipositor of typicAl morphology (see ErmiloV & StArý 2017), elongAted (200, 36), blAdes (86) shorter thAn length of distAl section (beyond middle fold; 114). EAch of three blAdes with four smooth setAe; ψ1 ≈ τ1 (41) setiform, ψ2 ≈ τ a ≈ τ b ≈ τ c (16) thorn-like. Six coronAl setAe (4) spiniform.

Legs ( Figs 13–16 ). TridActylous, mediAn clAw thicker thAn lAterAls, All bArbed dorsAlly. LAterAl clAws with one tooth VentrodistAlly. DorsopArAxiAl porose AreAs on femorA And trochAnters III, IV, posteroVentrAl porose AreAs on tArsi And AnteroVentrAl porose AreAs on tibiAe well Visible. FormulAs of leg setAtion And solenidiA: I (1–5–3–4–20) [1–2–2], II (1–5–3–4–15) [1–1–2], III (2–3–1–3–15) [1–1–0], IV (1–2–2–4–12) [0–0–0]; homology of setAe And solenidiA indicAted in TAble 1. SolenidiA ω1 on tArsi I, ω1 And ω2 on tArsi II And σ on genuA II, III thickened, bluntended, other solenidiA longer, setiform. FAmulus of tArsi I short, strAight, dilAted And truncAted distAlly, inserted between ω2 And ft.

Roman letters refer to normal setae, Greek letters to solenidia (except ɛ = famulus). Single prime (’) marks setae on the anterior and double prime (’’) setae on the posterior side of a given leg segment. Parentheses refer to a pair of setae. Tr—trochanter, Fe—femur, Ge—genu, Ti—Tibia, Ta—tarsus.

Type deposition. The holotype And three pArAtypes Are deposited in SMNH; 15 pArAtypes Are deposited in TSUMZ; 16 pArAtypes in UPLBMNH.

Etymology. The specific nAme isabelaensis refers to the Philippine IsAbelA ProVince, where the present new species wAs collected.

Remarks. Neoribates isabelaensis sp. nov. is morphologicAlly most similAr to Neoribates barbatus HAmmer, 1968 known from New ZeAlAnd in hAVing trAnslAmellA, long prodorsAl setAe, conVex Anterior mArgin of notogAster, in the presence of four pAirs of genitAl setAe And in locAlizAtion of AdAnAl setAe ad 3 in preAnAl position. HoweVer, the new species differs from the lAtter by its smAller body length (448–547 Versus 950), pointed rostrum (Versus rounded), long And setiform bothridiAl setAe (Versus medium size, slightly dilAted mediodistAlly), locAlizAtion of notogAstrAl setAe h 1 And h 2 close to eAch other (Versus distAnced from eAch other), And the strong sexuAl dimorphism expressed in the structure of posterior pArt of notogAster (Versus Absent).

Figures

FIGURE 1. Neoribates isabelaensis sp. nov., adult: malE, dorsal viEW. ScalE bar 50 µm.

FIGURE 2. Neoribates isabelaensis sp. nov., adult: malE, vEntral viEW (gnathosoma and lEgs not shoWn). ScalE bar 50 µm.

FIGURES 3 – 5. Neoribates isabelaensis sp. nov., adult: 3 — malE, prodorsum (latEral sidEs not shoWn), frontal viEW; 4 — fEmalE, postErior part of notogastEr, dorsal viEW; 5 — malE, antErior part of body, latEral viEW. ScalE bar 50 µm.

FIGURES 6 – 7. Neoribates isabelaensis sp. nov., adult, postErior viEW: 6 — malE; 7 — fEmalE. ScalE bar 100 µm.

FIGURES 8 – 12. Neoribates isabelaensis sp. nov., adult: 8 — malE, postErior part of body, latEral viEW; 9 — fEmalE, postErior part of body, latEral viEW; 10 — subcapitulum of fEmalE, vEntral viEW; 11 — palp of fEmalE, right, antiaxial viEW, and postpalpal sEta; 12 — chElicEra of fEmalE, right, antiaxial viEW. ScalE bars 50 µm (8, 9), 15 µm (10 – 12).

FIGURES 13 – 16. Neoribates isabelaensis sp. nov., adult: 13 — lEg I, right, antiaxial viEW; 14 — gEnu, fEmur and trochantEr of lEg II, right, antiaxial viEW; 15 — gEnu, fEmur and trochantEr of lEg III, lEft, antiaxial viEW; 16 — lEg IV, lEft, antiaxial viEW. ScalE bar 20 µm.

FIGURES 17 – 20. Neoribates isabelaensis sp. nov., adult: 17 — fEmalE, dorsal viEW; 18 — malE, dorsal viEW; 19 — fEmalE, postErior viEW; 20 — malE, postErior viEW. ScalE bar 60 µm.