Brachioppiella (Gressittoppia) ricknuttalli

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

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Brachioppiella (Gressittoppia) ricknuttalli

sp. nov.

Brachioppiella (Gressittoppia) ricknuttalli  sp. nov.

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

Prodorsum ( Fig. 10View FIGURE 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. 10View FIGURE 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 c 2 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. 10View FIGURE 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. 10View FIGURE 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. 9View FIGURE 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 ( NMBAbout NMB 3302.68.1) and seven paratypes ( NMB 3302View Materials.68.2, NMBAbout NMB 3476.32.2) are deposited in the Acarology collection of the National Museum, Bloemfontein, South Africa  . Three paratypes ( SMNGAbout SMNG, DNR 56552View Materials) 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).


Naturhistorishes Museum


Senckenberg Museum fuer Naturkunde Goerlitz