Anderemaeus sidorchukae,

Norton, Roy A. & Ermilov, Sergey G., 2019, Anderemaeus (Acari, Oribatida) - overview, three new species from South America and reassessment of Anderemaeidae supported by ontogeny, Zootaxa 4647 (1), pp. 241-289: 251-256

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Anderemaeus sidorchukae

sp. nov.

Anderemaeus sidorchukae  sp. nov.

( Figs 1–9View FIGURE 1View FIGURE 2View FIGURE 3View FIGURE 4View FIGURE 5View FIGURE 6View FIGURE 7View FIGURE 8View FIGURE 9)


Anderemaeus  species with adults 547–669 long. Cerotegument with polyp-like excrescences, having ‘bouquet’ of many short tentacles. Rostrum with terminal mucro. Lamella simple in form, pair well separated anteriorly, such that mutual distance of cusps (and setae le) slightly greater than that of setae ro; prolamella absent; transverse prelamellar ridge absent. Seta in long, inserted on strong tubercle close to anterior margin of notogaster. Bothridial seta long, baculiform. Notogastral setae short, thick, densely barbed. Femora III, IV with small ventral keel, without spines or teeth; trochanters III and IV dorsodistally with small tooth, III also with strong proximal spine.

This is the only known Anderemaeus  species combining short notogastral setae with a long, baculiform bothridial seta. The cerotegument excrescences, with many short tentacles, are unique.


Measurements. Holotype (male) length 597, maximum notogastral width 398; range (including 2 female, 3 male paratypes) 547–630 × 365–431. Females larger than males: 614–630 × 415–431 vs. 547–597 × 365–398. Two nontype females from Concepción slightly larger: 642 × 456 and 669 × 476.

Integument. Cuticle shiny in reflected light ( Fig. 3AView FIGURE 3). Cerotegument ( Fig. 4View FIGURE 4 A–E) with larger excrescences mostly polyp-like, with short stalk and head with more than two dozen short arms; smallest excrescences spherical; various extraneous spores often attached, but usually with little organic or mineral debris.

Prodorsum ( Figs 1–3View FIGURE 1View FIGURE 2View FIGURE 3). Rostrum with terminal mucro, rostral bulge modestly developed. Lamella simple in form, without lateral tooth or prolamella; pair well separated anteriorly, such that mutual distance of cusps (and setae le) slightly greater than that of setae ro; transverse prelamellar ridge absent. Without noticeable foveation between lamellae. Setae ro (51–55), le (61–65) and ex (28–32) attenuate, weakly barbed; in (114–127) acicular, with stronger barbs, inserted on distinct tubercle close to anterior margin of notogaster. Bothridial seta (bs; Fig. 1AView FIGURE 1, 3CView FIGURE 3) directed laterally to posterolaterally; long (127–135), but shorter than mutual distance of pair; baculiform or slightly tapered distally (weakly spindle-shaped in one non-type specimen; Fig. 3DView FIGURE 3), with minute, inconspicuous barbs.

Notogaster ( Figs 1View FIGURE 1, 2View FIGURE 2). Without noticeable foveolation in reflected light ( Fig. 3AView FIGURE 3). Humeral process present, but not strongly projecting. Notogastral setae comparatively short (32–41), thickened, densely barbed, sometimes slightly dilated medially ( Fig. 4BView FIGURE 4); all inserted on small tubercles. Seta c curving posteriorly, ending well short of lyrifissure ia; others erect. Setae lm and la nearly in transverse line (lm slightly anterior), lm distinctly closer to la than to c; mutual distance of pair lm about four times setal length; h 2 medial to h 3.

Coxisternum ( Figs 1BView FIGURE 1, 3F, GView FIGURE 3). Enantiophysis e3 present, spanning groove of epimeral border bo.3, its anterior tubercle connected by low ridge across epimere III to larger tubercle just posterior to ventrosejugal groove, bearing seta 3b at base; seta 3c inserting at base of separate sharp tubercle. Aggenital enantiophysis (e4) well developed across border bo.4, its posterior tubercle about 3 times as large as anterior; latter, bearing seta 4b, connected across epimere IV to posterior tubercle of e3 by low ridge. Epimeral setae thin, attenuate, weakly and sparsely barbed; 3c and 4c (28–32) longer than others (20–24).

Anogenital region ( Figs 1BView FIGURE 1, 2AView FIGURE 2). Setae thin, attenuate, smooth or sparsely barbed.Anterior genital seta (20–24) slightly longer than others (16–20); aggenital (20–24), anal (16–20) and adanal (20–24) setae in typical positions. Preanal organ only slightly expanded internally.

Gnathosoma ( Fig. 5View FIGURE 5). Subcapitulum longer than wide (123–131 × 86–94). Subcapitular setae attenuate, barbed, h (28–32) longer than a and m (24–28). Adoral setae (12–16) attenuate, smooth. Palps (86–90) and postpalpal seta (8) typical of genus. Chelicerae (123–131) typical of genus; seta cha (36–41) longer than chb (24–28), both barbed.

Legs. Form and proportions of segments shown in Fig. 6View FIGURE 6. Tarsi significantly (I, II) to slightly (III, IV) longer than respective tibiae. Genua I, II notably longer than III, IV. Femora III, IV elongated, length about twice width, each with small ventral keel ( Fig. 3KView FIGURE 3). Trochanters III, IV dorsodistally with small, triangular tooth; III with additional long proximal spine; IV with small keel in distal half. Form and locations of setae in Fig. 6View FIGURE 6, summarized in Table 1. Solenidia relatively long: σ of genua I subflagellate, σ III more than twice segment length; φ of tibiae II–IV sub-flagellate.


( Figs 7–9View FIGURE 7View FIGURE 8View FIGURE 9)

Length and width of larva 249–265 × 116–132 (n =2), protonymph 348–365 × 199 (n =3), deutonymph 466 × 245 (n =1), tritonymph 581 × 348 (n =1). Bothridial setae in larva and protonymph spindle-form, with long stalk, short lanceolate head and attenuated tip, distinctly barbed; similar or nearly isodiametric ( Fig. 4GView FIGURE 4) in later nymphs.

Material examined

Holotype (male): Chile, Maule Region, Talca Province, Alto Vilches , 1160 m a.s.l., 18-I-1985, N. Platnick and O. Francke, from montane forest litter  . Paratypes: 5 (2 females, 3 males) from same collection as holotype; 2 (unsexed) from Bio Bio Region, Concepción Province, 6 km south of Concepción , 365 m a.s.l., 22-I-1985, N. Platnick & O. Francke, from pine forest litter. Juveniles (non-type): 7 (2 larvae, 3 proto-, 1 deuto- and 1 tritonymph) with same data as holotype  .

Type deposition

The holotype is deposited in the SMNH; five paratypes are deposited in the TSUMZ, and one in the UCMZ, preserved in ethanol with a drop of glycerol. One slide-mounted paratype in personal collection of RAN.


The specific epithet sidorchukae  honors the late Russian acarologist and paleontologist Ekaterina A. Sidorchuk (see Lindquist & Norton 2019, Rasnitsyn 2019). Katya’s absence as a colleague and friend will long be deeply felt.