Acaroceras (Acaroceras) brasiliensis, Ermilov & Tolstikov, 2015

Ermilov, S. G. & Tolstikov, A. V., 2015, The oribatid mite genus Acaroceras (Acari, Oribatida, Microzetidae), Acarologia 55 (1), pp. 61-69 : 62-66

Acaroceras (Acaroceras) brasiliensis n. sp.

( Figures 1-3 )

Diagnosis — Body size: 192 – 196 × 147 – 151. Rostrum rounded. Two pairs of horn-like lobed structures present in anterior part of prodorsum. Lamellae rounded distally. Interlamellar apophysis bifurcate, three pairs of transverse lamellar apophyses located under inner parts of lamellae. Lamellar setae talon-like, with ciliate branches. Interlamellar setae long, rfar beyond the rostrum. Pteromorphs pointed distally and with tooth on anterior margin. Notogastral setae minute, smooth. Epimeral setae setiform, barbed, little varied in length. Anterior pair of genital setae and aggenital setae well developed, barbed; other genital setae and anal and adanal setae minute, smooth.

Description — Measurements. Body length: 192 (holotype: male), 192 – 196 (two paratypes: both males); body width: 147 (holotype), 147 – 151 (two paratypes).

Integument — Body color light brownish to brown. General body surface smooth. Prodorsum between lamellae covered densely by filamentous cerotegument, notogaster covered by indistinct microgranular cerotegument. Lateral part of prodorsum and pedotecta I, and ventral plate nearly to posterior part of circumpedal carinae with short striae. Epimeral region with four long, strong longitudinal striae.

Prodorsum — Rostrum rounded. Two pairs of lobed structures present near to rostrum, all hornlike, directed upward in medio-basal part, and slightly backwards in distal part. Anterior pair (sl1) longer and thinner than posterior pair (sl2). Lamellae wide, fused medially in basal part by interlamellar apophysis (ap). Lamellae distally wide, outer and inner distal parts rounded, without teeth and indentations. Interlamellar apophysis bifurcate, with short, rectangular basal part and two long, thin branches, not reaching the level of insertions of lamellar setae. In addition, three pairs of transverse lamellar apophyses present: anterior (apa) and medial (apm) pairs simple, posterior pair (app) bifurcate. Rostral setae (ro, 41 – 45) setiform, slightly barbed, inserted on large tubercles. Lamellar setae (le, 16 – 20) talon-like, with eight long (41 – 49), simple, thin branches. Interlamellar setae (in, 110 – 123) setiform, thickened, smooth, far beyond the rostrum. Bothridial setae (ss, 98 – 106) setiform thickened, densely ciliate. Exobothridial setae and their alveoli not visible. Tutoria (tu) with long knifelike cusp.

Notogaster — Anterior margin distinct, straight. Pteromorphs pointed distally (t), with tooth (tp) on anterior margin. Nine pairs of short, setiform, smooth notogastral setae present, c (8) longer than others (4). All lyrifissures (ia, im, ip, ih and ips) distinct. Opisthonotal gland openings (gla) located posteriorly to im.

Gnathosoma — Generally, morphology is typical for Microzetidae (for example, Grandjean 1936; Engelbrecht 1972; Ermilov and Anichkin 2011; Ermilov et al. 2013). Subcapitulum slightly longer than wide (49 – 53 × 45 – 49). Subcapitular setae (h, m, a) setiform, barbed, similar in length (12). Two pairs of adoral setae (or) minute (4), thin, smooth. Palps (45) with setation 0-2-1-3-9(+ ω). Chelicerae (57) with two setiform, barbed setae: cha (24) longer than chb (16). Cheliceral tubercle (8) straight, bluntended.

Epimeral and lateral podosomal regions — Epimeral setal formula: 3-1-3-3. All setae (16 – 24) simple, barbed. Setae 3c inserted on pedotecta II; setae 4c inserted on discidia. Epimeral border IV well developed. Pedotecta I (Pd I) large, scale-like (in lateral view), covering acetabula I. Pedotecta II (Pd II) rounded distally (in ventral view), partly covering acetabula II. Discidia (dis) large, triangular, rounded. Circumpedal carina (cp) distinct.

Anogenital region — Six pairs of genital setae simple, g 1 (14 – 16) slightly barbed, thicker and longer than other smooth setae g 2 - g 6 (4). One pair of aggenital setae (ag, 12 – 14) setiform, slightly barbed. Two pairs of anal (an 1, an 2, 4) and three pairs of adanal (ad 1 - ad 3, 4) setae minute, thin, smooth. Lyrifissures iad located in paraanal position.

Legs — Generally, morphology is typical for Microzetidae (for example, Grandjean 1936; Engelbrecht 1972; Ermilov and Anichkin 2011; Ermilov et al. 2013). Claw of each leg smooth. Formulas of leg setation and solenidia: I (1-5-3-4-19) [1- 2-2], II (1-5-3-4-15) [1-1-2], III (2-3-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology indicated in Table 1. Antero-ventral part of femora IV serrate (ser). Setae p setiform on tarsi I, thorn-like on tarsi II-IV. Famulus short, setiform, straight. Solenidia ω 1 on tarsi I and φ 1 on tibia I setiform, long, other solenidia short, slightly thickened, blunt-ended.

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

Etymology — The name of the new species refers to the country of origin, Brazil.

Comparison — The known species of the genus Acaroceras can be distinguished by the key which is presented below.

Figures

FIGURE 1: Acaroceras (Acaroceras) brasiliensis n. sp.: A – dorsal view; B – frontal view. Scale bar 50 µm.

FIGURE 2: Acaroceras (Acaroceras) brasiliensis n. sp.: A – ventral view (legs not illustrated); B – posterior view. Scale bar 50 µm.

FIGURE 3: Acaroceras (Acaroceras) brasiliensis n. sp.: A – lateral view (legs not illustrated); B – subcapitulum, ventral view; C – trochanter, femur and genu of leg I, left, paraxial view; D – femur, genu and tibia of leg II, left, antiaxial view; E – trochanter, femur and genu of leg III, right, antiaxial view; F – leg IV, right, antiaxial view. Scale bar 20 µm.