Anderemaeus Hammer, 1958,

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: 243-251

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https://doi.org/10.11646/zootaxa.4647.1.17

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lsid:zoobank.org:pub:6B225596-A393-40E9-A386-8758A5ABC5D6

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http://treatment.plazi.org/id/03DD87AF-FFD1-9676-70DE-225EFC89FC99

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scientific name

Anderemaeus Hammer, 1958
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Genus Anderemaeus Hammer, 1958 

Type species: Anderemaeus monticola Hammer, 1958, p. 62  Diagnosis

Anderemaeidae  (see Balogh 1972; Balogh & Balogh 1985) with adults of medium size, length ca. 350–830. Cuticle conspicuously foveate on projecting structures of prodorsum and podosoma; cerotegument (cuticular secretion layer) abundant, with spherical to columnar excrescences. Prodorsum with paired blade-like tutoria and converging lamellae; each lamella with or without small cusp bearing seta le, each tutorium proximally forming part of prodorsal enantiophysis. Bothridium strongly projecting, seta baculiform to clavate. Dorso- and pleurophragmata absent. Lateral podosoma with pedotecta I and II and large discidium. Circumpedal carina and aggenital enantiophysis present; preanal organ hollow, tubular to distinctly expanded internally. Notogaster with rectangular humeral process and relatively straight anterior margin, but immovably fused with prodorsum within distinct dorsosejugal furrow; with 10 pairs of setae, lm positioned medially; without porose organs. Coronal setae absent from ovipositor. Chelicera chelate-dentate; rutellum pantelobasic; palp solenidion independent, prone. Legs relatively short, thin; pretarsi heterotridactylous; seta d lost from all tarsi and genua I–III; iteral setae present on tarsi I–III. Juveniles without exuvial scalps; nymphs lacking centrodorsal setae, c 1, c 3, l - and h -series flagellate; opisthonotal gland of nymphs opening on long stalk.

Adult

( Figs 1–6View FIGURE 1View FIGURE 2View FIGURE 3View FIGURE 4View FIGURE 5View FIGURE 6, 10–15View FIGURE 10View FIGURE 11View FIGURE 12View FIGURE 13View FIGURE 14View FIGURE 15, 17–24View FIGURE 17View FIGURE 18View FIGURE 19View FIGURE 20View FIGURE 21View FIGURE 22View FIGURE 23View FIGURE 24)

Modified and expanded from Hammer 1958.

Length ca. 350–830, mostly greater than 550. Color in preserved, mature specimens dark reddish-brown to light tan ( Fig. 12View FIGURE 12 A–C; except for teneral specimens, lighter colors probably due to gradual bleaching). Cuticle partly with distinct sculpturing, microtuberculate locally (e.g. Fig. 3EView FIGURE 3): projecting structures of prodorsum and podosoma (lamella, tutorium, pedotecta, parietal walls of acetabula, various carinae) conspicuously foveate ( Figs 3JView FIGURE 3; 12D, GView FIGURE 12); notogaster unsculptured or shallowly, inconspicuously foveolate (i.e., with smaller, well-spaced circular depressions); venter mostly without foveation. Cerotegument encrusting body and basal parts of legs; excrescences spherically granular in some areas, but mostly columnar, from simple to variously ornamented ( Figs 4View FIGURE 4, 13View FIGURE 13, 21View FIGURE 21, 23View FIGURE 23); with ( Figs 12AView FIGURE 12, 22JView FIGURE 22) or without particles of exogenous organic and mineral debris.

Rostrum subtriangular in dorsal view, with ( Fig. 1AView FIGURE 1) or without ( Fig. 17View FIGURE 17) small terminal mucro; with medial bulge (rb) in rostral limb between rostral setae, bulge strongly excavated on ventral (‘internal’) face ( Figs 2AView FIGURE 2, 11AView FIGURE 11, 20FView FIGURE 20; see R1); some species with margin of limb extended posteriorly as laterorostral carina (lr; Figs 2AView FIGURE 2, 3JView FIGURE 3), reaching parietal wall of acetabulum I and forming prodorsal contour in dorsal view; border of camerostome below carina smooth, irregularly scalloped or toothed. Lamella about two-thirds length of prodorsum, pair convergent but separated anteriorly; each formed as thin, near-vertical blade starting at bothridium and ending at insertion of lamellar seta, usually on small, tubular cusp, hardly longer than wide ( Fig. 2AView FIGURE 2, 3JView FIGURE 3 insert); lamella continuing, or not, short distance past cusp as low, narrow prolamella (prl; Fig. 19D, GView FIGURE 19). Transverse prelamellar ridge (plr; Figs 10AView FIGURE 10, 11AView FIGURE 11) present or absent. Tutorium thin, blade-like (tu; Figs 2AView FIGURE 2, 3JView FIGURE 3); height decreasing anteriorly to efface without cusp, usually between levels of lamellar and rostral setae; with abrupt posterior end, opposing separate tubercle to form prodorsal enantiophysis (ea). Posterodorsal tubercles present in various configurations or absent. Without dorso- or pleurophragma; cheliceral retractor and subcapitular levator muscles inserting directly on external prodorsal cuticle ( Fig. 21BView FIGURE 21). Bothridium strongly projecting ( Fig. 23GView FIGURE 23), emarginate laterally; bothridial seta (bs) of various form, baculiform to clavate ( Figs 3C, DView FIGURE 3, 23GView FIGURE 23); usually with minute, inconspicuous barbs or scalloping, restricted to clear, isotropic outer cuticle layer. Interlamellar seta (in) long, erect, inserted on small or conspicuous tubercle; exobothridial seta (ex) shortest, inserted posterior to prodorsal enantiophysis and dorsal to alveolar vestige (exv) of second exobothridial seta ( Fig. 2AView FIGURE 2); lamellar (le) and rostral (ro) setae intermediate in size.

Circumgastric scissure (cgs; Fig. 2AView FIGURE 2) incomplete: fully developed posteriorly, but gradually narrowing anteriorly to efface in humeral region. Notogaster without posterior tectum ( Fig. 20CView FIGURE 20); with discrete, straight anterior margin but fused to prodorsum across distinct dorsosejugal groove; line of fusion indicated by internal transverse incision (t.inc; Figs 12IView FIGURE 12, 21AView FIGURE 21; see R2). With projecting, rectangular humeral process (hpr; Figs 1AView FIGURE 1, 2AView FIGURE 2) aligned with bothridium across sejugal groove, and weak to well-defined ridge (‘crista’) running posteriorly from process, best seen in lateral view (cr; Figs 2AView FIGURE 2, 11AView FIGURE 11). Ten pairs of notogastral setae, lm with central position; usually with conspicuous barbs extending from birefringent core. Opisthonotal gland opening (gla) and normal complement of five lyrifissures (ia., im, ip, ih, ips) present, in typical positions ( Figs 2AView FIGURE 2, 11A, BView FIGURE 11).

Podosoma with pedotectum I (PdI; Figs 1BView FIGURE 1, 12GView FIGURE 12) of medium size, uniformly curved; with vertical pleural ridge (vpr; Fig. 2AView FIGURE 2, 3JView FIGURE 3) running from its dorsal end to near insertion of exobothridial seta, usually as distinct carina; pedotectum II (PdII) smaller, scaliform. Circumpedal carina (cir; Figs 2AView FIGURE 2, 3IView FIGURE 3) sharply defined, originating near posterior margin of acetabulum IV, then curving to approach circumgastric scissure asymptotically, ending below humeral process; lateral portion foveate. Coxisternum with epimeral borders mostly well-delineated ( Figs 1BView FIGURE 1, 3B, GView FIGURE 3, 20BView FIGURE 20): bo.1 complete medially; bo.2 indistinct, incomplete or irregular medially; bo.sj and bo.3 complete, transverse; bo.4 slightly oblique, merging with genital rim to meet with bo. 3 in vague X-pattern; sternal borders (midline) often variable, absent to weakly defined. Surface distinctly grooved at posterior three borders ( Fig. 21GView FIGURE 21); bo.4 spanned by large aggenital enantiophysis (e4), bo.3 with or without enantiophysis e3; seta 3b, on or near tubercle posterior to groove of bo.sj. Apodemes differing in form: ap.1 ( Fig. 21HView FIGURE 21) large, with thickened, sloping medial edge, pair forming approximate V-shape when viewed face-on; ap2 ( Fig. 23HView FIGURE 23) also large, with near-vertical thickened edge, pair well separated; ap.sj ( Fig. 23IView FIGURE 23) small, oblique, penetrated by trunk of sejugal trachea; ap.3 ( Fig. 23JView FIGURE 23) small, indistinct, merging with thick bo.3 to form apparent wall-like band across coxisternum; ap.4 essentially absent ( Figs 21IView FIGURE 21, 23KView FIGURE 23). Tracheal system normal, with tr1 and tr.sj double-branched ( Fig. 23D, IView FIGURE 23), tr3 single. Epimeral setal formula (I–IV) 3–1–3–3 ( Figs 1BView FIGURE 1, 10BView FIGURE 10; see R3).

Anogenital region with six pairs of genital (see R4), one pair of aggenital, two pairs of anal and three pairs of adanal setae; ad 1 and ad 2 posterior to, ad 3 lateral to anal aperture. Lyrifissure ian absent; iad oblique, removed from anal plate at level near that of an 2. Preanal organ (pr.o; Figs 1BView FIGURE 1, 21C, DView FIGURE 21) hollow, caecum-like, tubular or expanded internally. Posteromedial corner of each anal plate with long, narrow strut (po.st; Fig. 21E, FView FIGURE 21) serving for attachment of postanal suspensor muscle (mu.ps); pair approximate, but not merging. Ovipositor (ovp; Fig. 21DView FIGURE 21) with lobes occupying about half length of distal section; with normal complement of 12 setae, four on each lobe, all similar in size; coronal setae absent. Spermatopositor (sp; Fig. 23KView FIGURE 23) small, typical of Brachypylina.

Subcapitulum diarthric, without axillary saccule; rutellum (ru; Fig. 5AView FIGURE 5) pantelobasic, with typical dentition and rutellar brush (rbr). Chelicera ( Figs. 5DView FIGURE 5, 14DView FIGURE 14) chelate-dentate, slightly elongated (~3 times longer than deep), with relatively small chela occupying about one-quarter of cheliceral length; usually with 1–2 minute denticles proximal to seta cha; Trägårdh’s organ (Tg) relatively narrow. Palp ( Figs 5CView FIGURE 5, 14CView FIGURE 14) with usual setal formula: 0–2–1–3–9(+ ω); setae of trochanter to tibia long, attenuate, barbed. Tarsus with four short, blunt distal eupathidia— acm, sul, (ul); other tarsal setae smooth or with sparse, inconspicuous barbs; solenidion ω free of setal attachments, narrowly baculiform, appressed to palp surface. Postpalpal seta (ep; Fig. 13GView FIGURE 13) spiniform, smooth.

Legs ( Figs 6View FIGURE 6, 15View FIGURE 15, 19View FIGURE 19) relatively short, longest (IV) less than 2/3 body length. Pretarsi heterotridactylous, claws with sparse, minute, inconspicuous dorsal dentes. Tarsi spindle-shaped, without tendon guidage tubes. All tibiae and femora I, II clavate, with distinct proximal stalk. Femora and trochanters III, IV broadly expanded with short stalks hidden in adaxial view. Femora III, IV (and in some cases trochanters) with ventral keel or large blade; trochanters III, IV with fin-like basal process (bpr; Fig 13HView FIGURE 13, 22IView FIGURE 22), with or without prominent teeth or large spines. Porose area (p.a.; Figs 6View FIGURE 6, 22IView FIGURE 22) developed on adaxial face of each femur and on trochanters III and IV; none on tibiae or tarsi. Setal and solenidial counts as follows: I (1-5-3-4-20) [1-2-2], II (1-4-3-4-16) [1-1-2], III (2-3-2-3-15) [1-1-0], IV (1-2-3-3-12) [0-1-0]; homologies indicated in Table 1; notably, seta d absent from genua I–III and from all tibiae and iteral setae present on tarsi I–III. Proral (p’, p “) and subunguinal (s) setae eupathidial on tarsus I; famulus (e) small, simple, baculiform. Solenidion φ 1 of tarsus I flagellate, others vary with species.

Development

( Figs 4View FIGURE 4, 7–9View FIGURE 7View FIGURE 8View FIGURE 9, 16View FIGURE 16)

Based on all instars of A. sidorchukae  and nymphs of A. dentatus  ; for emphasis, data on adult included in formulas.

Facies, cuticle. Body pyriform, with hysterosoma about twice length of proterosoma; prodorsum distinctly sclerotized, gastronotum without major sclerites. Hysterosoma without permanent dehiscence line. Cuticle colorless to pale tan, smooth. Body and basal leg segments with cerotegument; excrescences in form of dense, short columns or subspherical ( Figs 4FView FIGURE 4, 16C, FView FIGURE 16); nymphs without exuvial scalps (apheredermous). Without porose apodemes or other tracheal organs.

Prodorsum. Setae ro and le attenuate, barbed, inserted on small tubercles; tubercle of le noticeably projecting in lateral view ( Fig. 16BView FIGURE 16) and extending posteriorly as indistinct ridge ( Fig. 16EView FIGURE 16). Seta in long (more than half length of prodorsum) and barbed in larva, minute, spiniform, roughened in nymphs. Seta ex attenuate but minute, inconspicuous.

Gastronotum. Setal formula 12-12-10, i.e., larva with unideficient setation; nymphs quadrideficient, lacking centrodorsal setae; adult further loses c 1, c 3. Most gastronotic setae long, finely attenuate to flagellate, barbed; insert- ed on projecting, lightly sclerotized tubercles varying in size proportionate to seta. Larva with pygidially positioned dp flagellate, pair on low mound; centrodorsal and laterodorsal setae, plus c 1, c 3, subflagellate; row h decreasing in length anteriorly ( Fig. 7BView FIGURE 7). Nymphs ( Figs 9AView FIGURE 9, 16AView FIGURE 16) with lm in lateral position (shifting to central position in adult), and pair h 1 flagellate, adjacent on weak shared sclerite ( Fig. 4IView FIGURE 4); pair c 1 close together, but not on shared sclerite; h 2 shorter than h 3. Opisthonotal gland opening on small tubercle in larva ( Fig. 7AView FIGURE 7) and in nymphs on long, posterolaterally directed tubular stalk ( Figs 4HView FIGURE 4, 16DView FIGURE 16), usually weakly flared at opening (see R5); gland contents lightly pigmented. Cupules ia, im, ip normal in form and position; im just dorsal to gla stalk ( Fig. 4HView FIGURE 4).

Venter. Epimeral setation (I–IV, larva to tritonymph: 3-1-2, 3-1-2-1, 3-1-2-2, 3-1-3-3 (none added in adult); epimeral setae attenuate, thin, smooth, except seta 1c of larva inconspicuous, forming protective scale over Claparède’s organ. Genital seta ontogeny (protonymph to adult) 1-3-5-6. Aggenital seta deutonymphal. Paraprocts glabrous (without vestiges) in larva, proto- and deutonymph; adanal (three pairs) and anal (two pairs) setae appear fully formed in proto- and deutonymph, respectively. Genital and adanal setae attenuate, slightly barbed, aggenital and anal setae attenuate, thin, smooth. Cupules ih, ips, iad and ian appearing in normal ontogenetic pattern (ian lost in adult).

Gnathosoma. Generally similar to adult. Subcapitulum slightly longer than wide. Subcapitular (including adoral) setae attenuate, smooth. Seta inf of palp femur added in protonymph.

Legs. Seta d of genua and tibiae well developed in all juveniles ( Fig. 8View FIGURE 8 D–F), strikingly long, subflagellate on tibia I of nymphs ( Fig. 16EView FIGURE 16); if coupled with solenidion, then lost without vestige in adult. Iteral setae tritonymphal on tarsi I-III, absent from IV in all instars. Protonymphal tarsus IV with typical seven setae, other segments glabrous. Full ontogeny of setae and solenidia given in Table 1.