Brachioppiella (Gressittoppia) ricknuttalli, Hugo-Coetzee, 2017

Hugo-Coetzee, Elizabeth A., 2017, New Oppiidae (Acari: Oribatida) from Vernon Crookes Nature Reserve, South Africa, Zootaxa 4311 (2), pp. 211-232 : 227

Brachioppiella (Gressittoppia) ricknuttalli sp. nov.

( Fig. 10 )

Diagnosis. Adult: body size 220–248 × 106–116; rostrum round with trapezoid extension; lamellar, interlamellar and exobothridial setae smooth, lamellar seta on tubercle; trapezoid shaped tubercle posterior to interlamellar seta; setae c 2 absent, nine pairs smooth, medium length notogastral setae, setae lm postero-medially to la, seta lp slightly antero-medially to h 3, h 3 slightly postero-medially to lyrifissure im; adanal setae ad 2 posterior to iad.

Description. Measurements. Length: females (n = 4) mean 245 (range 241–248), males (n = 6) 233 (225–239). width: females 115 (114–116), males 111 (106–115). Holotype (male): length 220, width 115.

Integument ( Fig. 10 A, C). Body surface smooth; small area of exobothridial region granulated.

Prodorsum ( Fig. 10 A, C). Rostrum rounded with trapezoid cerotegumental extension, so that rostrum often appear trapezoid; rostral seta (11–20) located dorsally, thin, weakly barbed, lamellar (4–12), interlamellar (3–7), exobothridial (6–11) setae thin, smooth, exobothridial seta inserted on tubercle, antero-laterally to bothridium; lamellar seta closer to interlamellar than to rostral seta; lamellar lines present, translamellar line absent, lamellar seta inserted on tubercle distally on lamellar line; posterior to interlamellar seta a trapezoid tubercle present; bothridial seta (36–42 without branches) fusiform, pectinate with seven to nine branches, distal two branches not merged, branches becoming progressively shorter distally; muscle sigillae could not be observed; tubercle in dorsosejugal region on hysterosoma absent; pedotectum I typical for genus.

Notogaster ( Fig. 10 A, C). Nine pairs of smooth notogastral setae, la, lm, lp, h 1, h 2, h 3 (7–16)> p 1, p 2, p 3 (5–9), lp longest, seta c2 absent, represented by alveolus, seta lm slightly postero-medially to la, setae lp, h 3 in close proximity, h 3 slightly postero-laterally to lp and postero-medially to im; lyrifissure ia, im distinct (6–9), other lyrifissures not visible.

Gnathosoma and epimeral region ( Fig. 10 B). Setae a, m (6–11) thin, weakly barbed, h (5–11), thin, smooth; all epimeral setae thin, smooth, except seta 3c weakly barbed; 3c, 4a, (8–14)> 1b, 1c, 3b (6–11)> 1a, 2a, 3a, 4b, 4c (4–9); discidium triangular distally.

Anogenital region ( Fig. 10 B). All setae thin, smooth, short; four pairs of genital setae (3–4), g 1 on anterior border of genital plate; one pair of aggential (6–8), two pairs of anal (4–6), three pairs of adanal (4–7) setae, ad 2 posterior to iad (6–10).

Legs. Leg IV (146–162)> leg I (123–145)> leg III (120–130)> leg II (97–114); leg setation and morphology the same as B. martinezi sp. nov. (see Table 2 and Fig. 9 A–D).

Etymology. The species is named in honour of Mr. Rick Nuttall, the director of the National Museum, Bloemfontein, for his support in taxonomical research.

Type material. The holotype and two paratypes were collected in Vernon Crookes Nature Reserve, KwaZulu- Natal (3017.165’S, 3035.150’E) by D.J. Kok, 31.III.1983 from soil and decomposed plant material. Eight paratypes were collected from Vernon Crookes Nature Reserve by D.J. Kok, 24.III.1986 from rich organic soil. The holotype ( NMB 3302.68.1) and seven paratypes ( NMB 3302 .68.2, NMB 3476.32.2) are deposited in the Acarology collection of the National Museum, Bloemfontein, South Africa . Three paratypes ( SMNG, DNR 56552) are stored in Senckenberg Museum für Naturkunde, Görlitz, Germany .

Remarks. Brachioppiella (G.) ricknuttalli sp. nov. is most similar to B. (G.) moresonensis from South Africa, Brachioppiella (G.) pepitensis pepitensis ( Hammer, 1962) from the southern Neotropical region and Antarctica, and Brachioppiella (G.) pepitensis brevipectinata ( Covarrubias, 1968) from South Shetland Islands, in having weak to distinct lamellar lines and seta lm postero-medially to la. However, the new species differ from the others in the relative position of setae lp and h 3 ( B. ricknuttalli sp. nov. antero-medially; B. moresonensis , B. pepitensis brevipectinata postero-medially; B. pepitensis pepitensis transverse line), the relative position of seta h 3 to lyrifissure im ( B. ricknuttalli sp. nov. slightly postero-medially; B. moresonensis anteriorly; B. pepitensis posteriorly).

The five species now known from South Africa differ in terms of the following selected characteristics: the position of notogastral setae lm relative to la ( B. martinezi sp. nov., B. corallifera antero-medially; B. ricknuttalli sp. nov., B. moresonensis postero-medially; B. orkneyensis posterior), relative position of seta h 3 to lyrifissure im ( B. moresonensis anterior; others species posterior or postero-medially), notogastral setae smooth or ciliate ( B. corallifera ciliate; other species smooth), lamellar lines ( B. martinezi sp. nov., B. moresonensis present; other species absent), form of bothridial seta ( B. corallifera slightly thickened; other species fusiform).

Figures

FIGURE 9. Brachioppiella (Gressittoppia) martinezi sp. nov. A. Leg I, right, antiaxial view; B. leg II, left, antiaxial view; C. leg III, left, paraxial view; D. leg IV, right, antiaxial view.

FIGURE 10. Brachioppiella (Gressittoppia) ricknuttalli sp. nov. (legs removed) A. Dorsal view; B. ventral view; C. lateral view (ventral setae not shown).