Lanceoppia (Bicristoppia) archicostulata, Ermilov, 2016

Ermilov, S. G., 2016, New Oppiidae (Acari, Oribatida) from Chile, Acarologia 56 (4), pp. 505-516 : 506-510

Lanceoppia (Bicristoppia) archicostulata n. sp.

( Figures 1-3)

Diagnosis — Body size: 233 – 241 × 131 – 143. Rostrum with median indentation. Costulae and transcostula present, arch-like. Interbothridial and postbothridial tubercles developed, rounded distally. Rostral setae setiform, barbed. Lamellar and interlamellar setae thin, erect, indistinctly barbed. Bothridial setae lanceolate, barbed. Notogastral setae c minute, other setae long, la and lm longest. Anogenital setae thin, setiform, smooth.

Description — Measurements – Very small species. Body length: 237 (holotype, female), 233, 241 (two paratypes: one female and one male); notogaster width: 135 (holotype), 131, 143 (two paratypes).

Integument — Body color light brownish. Body surface smooth, but lateral sides (between bothridia and pedotecta II and III) with tuberculate cerotegument (diameter of tubercles up to 2).

Prodorsum ( Figures 1A, 2A) — Rostrum with median, small, semioval indentation. Costulae (slightly shorter than half of prodorsum) and transcostula well developed, forming arch-like structure. Longitudinal rows, comprising several muscle sigillae, present in front of the bothridia. Interbothridial region with several (four to seven), indistinct muscle sigillae. Interbothridial (tub i) and postbothridial (tub p) tubercles strong, simple. Rostral setae (ro, 18-20) setiform, barbed, inserted dorso-laterally, directed antero-medially. Lamellar (le, 16) and interlamellar (in, 8-10) setae thin, erect, indistinctly barbed; le inserted posterior to transcostula. Exobothridial setae (ex, 4-6) minute, smooth, inserted on tubercles. Bothridial setae (bs, 44-48) with long stalks and shorter, lanceolate, barbed heads.

Notogaster ( Figures 1A, 2A) — Anterior border convex medially. One pair of tubercles located anterior to border, directed to postbothridial tubercles. Ten pairs of notogastral setae: c minute (2), other long (la, lm, 41 – 49; lp, h 1 - h 3, 24 – 26; p 1 - p 3, 16), setiform, smooth. Setae la inserted laterally to lm. Lyrifissures ia, im and ip and opisthonotal gland openings (gla) well visible, lyrifissures ih and ips not visible.

Gnathosoma ( Figures 1B, 2A) — Subcapitulum longer than wide (53 – 57 × 41 – 43). Subcapitular setae (a, m, h) similar in length (18 – 20), setiform, smooth. Palps (45) with setation 0-2-1-3- 8(+ω). Postpalpal setae (4) spiniform. Chelicerae (53 – 57) with two setiform, barbed setae; cha (20) longer than chb (12). Trägårdh’s organ tapered.

Epimeral and lateral podosomal regions ( Figures 1B, 2A) — Apodemes 4 semioval (forming a weak ridge in lateral view). Epimeral setal formula: 3-1-3-3; setae setiform, indistinctly barbed; 1c, 3c, 4a and 4c (20 – 24) longer than others (10 – 14). Pedotecta I represented by small laminae. Discidia (dis) well developed, triangular, pointed distally.

Anogenital region ( Figures 1B, 2A) — Six pairs of genital (g 1, 10-12; g 2 - g 6, 4 – 6), one pair of aggenital (ag, 16 – 18), three pairs of adanal (ad 1 - ad 3, 16 – 18) and two pairs of anal (an 1, an 2, 12 – 14) setae setiform, smooth. Adanal lyrifissures (iad) distinct, inverse apoanal.

Legs ( Figures 2 B-3) — Claw of each leg smooth. Trochanters III with one dorso-anterior tooth. Formulas of leg setation and solenidia: I (1-5-2-4-20) [1- 2-2], II (1-5-2-4-16) [1-1-2], III (2-3-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology of setae and solenidia indicated in Table 1. Setae p setiform on tarsi I, and very short, conical on tarsi II-IV. Solenidia ω 1 on tarsi I, ω 1 and ω 2 on tarsi II and σ on genua III thickened, blunt-ended, solenidia ’ on tibia II and III stick-like, erect, other solenidia setiform. Famuli () thickened, straight, inserted posteriorly to solenidia ω 1.

Material examined — Chile, vicinity of Punta Arenas, 53°38’02.8"S, 65°31’01.6"W, swamp, in Sphagnum magellanicum , 18.XI.2014 ( V. A. Stolbov and S.A. Ivanov) .

Type deposition — The holotype is deposited in the collection of the Senckenberg Institution , Görlitz, Germany ; two paratypes are deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia .

Etymology — The specific name archicostulata refers to the costulae and transcostula, which form the arch-like structure on the prodorsum.

Remarks — Lanceoppia (Bicristoppia) archicostulata n. sp. is morphologically most similar to L. (Bicristoppia) bicristata (Hammer, 1962(b)) from Argentina in having costulae, long notogastral setae and lanceolate bothridial setae. However, the new species differs from the latter by the well-developed transcostula (vs. transcostula absent), the presence of a median indentation on the rostrum (vs. rostrum rounded) and by setae la and lm being the longest on the notogaster (vs. dorsal notogastral setae similar in length).