Uroobovella oviformis, Kontschán & Starý, 2011

Kontschán, Jenő & Starý, Josef, 2011, Uropodina species from Vietnam (Acari: Mesostigmata), Zootaxa 2807, pp. 1-28 : 9

Uroobovella oviformis sp. nov.

( Figs 21–25 )

Material examined. Holotype. Female ( HNHM), Vietnam, Tam Dao, submontane foggy forest, litter sample, 1200 m, 16 October 1988, J. Starý coll. Paratypes. One female and one male ( ISB), locality and date same as holotype.

Description. Female. Length of idiosoma 590–600 µm, width 410–430 µm (n=2). Shape oval.

Dorsal idiosoma ( Fig. 21 ). Marginal and dorsal shields fused anteriorly. Dorsal shield with long, smooth needle-like setae, ca 23–29 µm, surface of dorsal shield smooth. Marginal setae smooth, similar in shape and length to dorsal setae, marginal shield without sculptural pattern.

Ventral idiosoma ( Fig. 22 ). Ornamentation on sternal shield absent. Eight pairs of sternal setae short (ca 7–8), smooth and needle-like. St1 situated near anterior margin of sternal shield, St2 near anterior margin of genital shield, St3 at level of central region of coxae II, St4 and St5 at level of posterior margin of coxae II, St6 at level of central region of coxae III, St7 at level of posterior margin of coxae III, St8 near posterior corners of genital shield. Ventral shield with seven pairs of smooth needle-like setae (ca 25–30 µm long). Two pairs of adanal setae and postanal seta similar in shape and length to ventral setae. Endopodal line present. Stigmata between coxae II and III. Peritremes hook-shaped. Genital shield linguliform, without sculptural pattern or anterior process. Tritostenum not clearly visible.

Gnathosoma ( Fig. 23 ). Corniculi horn-like, with smooth surface, internal malae longer than corniculi, their margins smooth. Hypostomal setae h1 smooth, ca 45 µm, situated near anterior margin of gnathosoma, h2 basally serrate, ca 30 µm, h3 smooth, ca 50 µm, h4 marginally serrate, ca 15 µm long. Epistome marginally serrate. Chelicerae with internal sclerotised node, movable digit shorter than fixed digit ( Fig. 24 ).

Legs with smooth and simple setae, leg I with ambulacral claws.

Male. Length of idiosoma 610 µm, width 420 µm (n = 1). Shape of idiosoma, ornamentation, and chaetotaxy of dorsum as in female. Eight sternal setae smooth, short (7–8 µm) and needle-like ( Fig. 25 ). Surface of sternal shield smooth, genital shield oval, situated between coxae II and III ( Fig. 25 ). Ventral setae and ornamentation similar to those of female, except one pair of additional ventral setae (Vx) present.

Etymology. The name of the new species refers to the egg-like shape of its idiosoma.

Remarks. The new species belongs to the Uroobovella ruehmi group on the basis of the following common characters ( Hirschmann, 1989): leg I with claws, peritremes hook-shaped, and idiosoma egg-shaped with wide marginal shields, presence of eight pairs of sternal setae, and the absence of fossula tarsales and pedales. Only six species other have been described from this species group. Hirschmann (1989) established a key to this group, and on the basis of this key the new species is closely related to Uroobovella parva Hiramatsu & Hirschmann , but these two species differ in the shape of female genital shield, which is oval in U. parva and linguliform in U. oviformis . The males differ in that the additional setae (Vx) is shorter than the other ventral setae in U. oviformis , but there are no differences in the length of ventral setae in U. parva .

Figures

FIGURES 21 – 25. Uroobovella oviformis sp. nov., female. 21, dorsal view; 22, ventral view; 23, ventral view of gnathosoma and palp; 24, chelicera, lateral view; 25, male, intercoxal region. (scale bar: 100 μm).