Bedoslohmannia anneae, Fernandez & Theron & Rollard & Castillo, 2014

Fernandez, Nestor, Theron, Pieter, Rollard, Christine & Castillo, Elio Rodrigo, 2014, Oribatid mites from deep soils of Hòn Chông limestone hills, Vietnam: the family Lohmanniidae (Acari: Oribatida), with the descriptions of Bedoslohmannia anneae n. gen., n. sp., and Paulianacarus vietnamese n. sp., Zoosystema 36 (4), pp. 771-787 : 773-780

publication ID

https://doi.org/ 10.5252/z2014n4a5

persistent identifier

https://treatment.plazi.org/id/03D0B226-FFA7-FFE9-1B64-615FFB8C90CF

treatment provided by

Felipe

scientific name

Bedoslohmannia anneae
status

sp. nov.

Bedoslohmannia anneae View in CoL n. sp.

( Figs 1-4 View FIG View FIG View FIG View FIG ; Table 1)

TYPE MATERIAL. — Holotype: Vietnam, Kien Giang Province; Kien Luong ; Nui Hon Chong “sommet est, flanc nord”, 27.I.2003, secondary forest, 1 ♀, Berlese funnel extraction of deep mineral soil. Louis Deharveng and Anne Bedos leg. (VIET-929) X 104.647086 ; Y 10.140744, alt. 120 m. Paratypes: same data, 2 ♀♀. MNHN, preserved in 70 % ethanol .

DIAGNOSIS (ADULT FEMALE)

Setation

Umbrella-shaped and simple.Umbrella-shaped:with two variations, one with rounded and more or less smooth edge, the other with spiky edge. Smooth edge: ro, le, exa, exp; notogastral, subcapitular h, m 2; epimeric; genital antiaxial; adanal; spiky edge: in setae. Simple setae: subcapitular a, m 1; paraxial genital; paraxial adanal. Umbrella-shaped setae covering almost entire body and legs.

Prodorsum

Triangular to polyhedral in dorsal view, anteriorly truncated in lateral view; postbothridial transverse band sb, poorly developed. Rostrum rounded; bothridium large, dorso-laterally opened;sensillus setiform, particularly curved, short barbs placed distally; in inserted between bothridia; Notogaster. Transverse bands not observed; setae 31-35 pairs: twelve pairs primary; 21-23 pairs additional neotrichial setae; all umbrella-shaped; c 1, c 2, c 3, d 1, d 2, cp, e 1, e 2, f 1, f 2, h 1, h 2 large; neotrichal setae small. Five pairs of lyrifissures present, ia, ip, below unsclerotized lateral longitudinal line; ips on adanal fold band; im above e 2 setae and ih posterior to h 2 setae.

Ventral region

Subcapitular setae, four pairs. Adoral setae: or 1 largest, with apical bead; or 2 elongate; or 3 small, sharply tipped. Chelicera: fixed digit, four teeth; chb seta well developed, cha seta only represented by insertion. Apodemata short, clearly visible; epimeric setal formulae 3-1-3-4. Anal setae two pairs; adanal setae four pairs.

Lateral region

Pedofossa housing retracted legs I-IV clearly visible; unsclerotized longitudinal line, terminating at level of ih lyrifissure.

Legs All claws monodactyle, with tooth antiaxially. Femur I, II with three umbrella-shaped setae; III, IV, with one only. Setal formulae I (0-4-3-4-17-1) (2-1-2); II (0-5-3-4-14-1) (1-1-2); III (2-4-2-3-12- 1) (0-1-1); IV (2-3-2-2-12-1) (1-0-0). Solenidia setiform; d setae present on tibia and genu I, II, III and only on genu IV.

DESCRIPTION

Measurements

530 µm (541–519) × 243 µm (260–230) (Holotype 1 ♀ and 2 ♀♀ paratypes measured).

Shape

Oval ( Fig. 1A, B View FIG ).

Colour

Specimens without setae: yellow to light brown; slightly shiny, when observed in reflected light.

Cerotegument

Almost nonexistent; only small amount present near insertion on first and second legs.

Integument

Polyhedral microsculpture on prodorsum, zone around bo, only visible in transmitted light.

Setation (legs not included; see Legs and Folding process)

Two types: umbrella-shaped and simple setae.

Two variants of umbrella shape: one with rounded and more or less smooth edge, the second with spiky edge. Smooth-edged variant found on: prodorsum ( Fig. 1B View FIG , ro, le, exa, exp setae); notogaster ( Fig. 1B View FIG , all setae); subcapitular ( Fig. 2E, h, m 2 View FIG ); epimeric ( Fig. 2B View FIG , all setae); genita ( Fig. 2D View FIG , (antiaxial setae); adanal setae ( Fig. 2D View FIG ). Spiky-edged variant: only in setae ( Fig. 1B View FIG ).

Simple setae on: subcapitulum, a, m 1 ( Fig. 2E View FIG ); paraxial zone of genital plate ( Fig. 2D View FIG ); paraxial setae adanal plate ( Fig. 2D View FIG ).

Umbrella-shaped setae presenting central zone with pedicel; upper part umbrella-shaped, with irregular margin and protuberances of different size and nerves ( Figs 1B View FIG ; 2B, D, E View FIG ).

Prodorsum

Triangular to polyhedral in dorsal view ( Fig. 1D View FIG ); triangular, but anteriorly truncated in lateral view ( Fig. 2A View FIG ). Rostrum broadly rounded; chitinous ridge present on either side of prodorsal area ( Fig. 1D View FIG ). Each ro seta inserted near the anterior edge of this ridge; le setae placed near ridge, short distance posteriorly and paraxially to ro; bo large, dorsolaterally opened; si setiform, particularly curved ( Figs 1A, B, D View FIG ; 2A View FIG ) with a few short barbs; in inserted between bothridia; exa situated near chitinous ridge. Umbrella-shaped setae covering almost entire prodorsum ( Fig. 1B View FIG ); shape difference between in and other prodorsal setae is notable ( Fig. 1B View FIG ).

Faint polygonate pattern present anterior and posterior bo. Postbothridial transverse band sb hardly discernible, only visible in specimens without setae ( Fig. 1D View FIG ). Dorsal view, due transparency (l.d) observed between exa and le ( Fig. 1D View FIG ).

Notogaster

Transverse bands not observed. Twelve pairs of primary notogastral setae: c 1, c 2, c 3, d 1, d 2, cp, e 1, e 2, f 1, f 2, h 1 and h 2 well discernible, and between 21-23 pairs of additional neotrichial setae ( Fig. 1C View FIG ), situated behind h 2. Umbrella-shaped setae covering almost entire notogaster ( Fig. 1B View FIG ).

Five pairs of lyrifissures present, ia, ip, situated below the unsclerotized lateral longitudinal line ( Fig. 2A View FIG ) (see Lateral region); ips situated on the adanal fold band ( Fig. 2C View FIG [BPAD]); im above e 2 setae and ih behind h 2 ( Fig. 2C View FIG ).

Lateral region

Prodorsal margin present on either side of cavities where legs I and II are housed when retracted; clearly visible prodorsal posterior margin (b.p) and attachment lines of articular skin λ 1 and λ 2 (with prodorsum and notogaster respectively) ( Fig. 2A View FIG ).

Anterior notogastral zones presenting conspicuous tectum ( Fig. 2A View FIG ) and clearly defined unsclerotized lateral longitudinal line, terminating almost at level of ih lyrifissure and delimiting notaspis (unpaired dorsal) and pleuraspis (paired narrow lateral zones) ( Fig.2A View FIG ); in posterior notogastral zone, when unsclerotized line does not exist, notaspis and pleuraspis not delimited ( Fig. 2A View FIG ).

Anteriorly each pleuraspis presenting a rounded lobe between legs II and III, where lyrifissure ia is present; posteriorly at level of d 3 and e 2 setae, well-marked edge forming roof of cavities in which legs III and IV are housed when retracted, with a protruding angle between them ( Fig. 2A View FIG ).

Ventral region

Subcapitulum anterior zone more or less triangular, posterior zone ovoid.Four pairs of subcapitular setae ( Fig. 2E View FIG ) (see Setation). Adoral setae characteristic: or 1 largest, with apical bead; or 2 elongate; or 3 with small sharp tip ( Fig. 2F View FIG ). Chelicera fixed digit with four teeth, one of them paraxial (indicated in Fig. 1F View FIG with dotted shading); chb setae well developed; only insertion of cha setae visible, situated laterally and posterior to chb ( Fig. 1E View FIG ).

Coxisternal region divided into two parts by the ventrosejugal groove. Apodemes short and clearly visible; epimeric setal formulae 3-1-3-4, all seta of similar shape ( Fig. 2B View FIG ) (See Setation). Genital plate undivided with ten pairs of setae ( Fig. 2D View FIG ); six simple setae aligned paraxially, four umbrellashaped setae antiaxially in semi-circle, following shape of genital plate margin. Preanal plate more or less triangular: anterior margin fused to posterior margin of genital opening, impossible to remove without breaking ( Fig. 2C View FIG ); posterior margin covering anterior part of ano-adanal plate, internally excavated to receive them ( Fig. 2C View FIG ).

Anal plate fused to adanal, resulting in single ano-adanal plate with six pairs of setae ( Fig. 2C, D View FIG ). Paraxial alignment of two simple setae situated in the middle posterior zone of the plate; antiaxial alignment with four umbrella-shaped setae ( Fig. 2C, D View FIG ). Band BPAD clearly visible in specimens immersed in lactic acid for a lengthy period; lyrifissure ips present near margin of this band ( Fig. 2C, D View FIG ).

Legs

Studying the legs is very complex, and due to limited number of adults available for study, it is necessary to consider our study preliminary (see Remarks).

Legs are particular by their shape, principally at femur level ( Fig. 3 View FIG A-D), and due to the presence of the very large umbrella-shaped setae.

Each claw bearing a single prominent tooth situated antiaxially ( Fig. 3 View FIG A-D).

Between tarsus and genu, all legs have a classic appearance, but femora present particular characteristics. Two types of femur can be distinguished. Femora legs I and II displaying large ventral blade ( Fig. 3A, B View FIG ), with two prominences, carrying three umbrella-shaped setae. Femora legs III and IV has ventral blade, with teeth, carrying only one umbrella-like seta ( Fig. 3C, D View FIG ).

Femur I robust, wide and long; ventral blade situated on proximal part, presenting two more or less rounded prominences, the distal largest; insertion of one umbrella-shaped seta on distal one. Second umbrella-like seta situated at the same level, but more dorsally, the third towards posterior near articulation with trochanter. Femur II differing in shape; narrower and less robust, ventral blade situated further back than in femur I. Proximal prominences small, polyhedral, and carry insertion of one umbrella-shaped seta; distal prominence rounded and larger than the previous. Second umbrellashaped seta situated distal to first, the third distal near articulation with trochanter.

Femur III presenting ventral blade with three teeth, umbrella-shaped seta situated towards distal; dorsal leaf-shaped setae present, small in relation to umbrella-shaped setae. Femur IV displaying more or less rounded blade with only two teeth; umbrella-shaped setae situated distal.

Setal formulae I (0-4-3-4-17-1) (2-1-2); II (0- 5-3-4-14-1) (1-1-2); III (2-4-2-3-12-1) (0-1-1); IV (2-3-2-2-12-1) (1-0-0).

All solenidia setiform; setae d present on tibia and genu I, II, III and genu IV, situated near solenidia ( Fig. 3 View FIG A-D).

Leg folding process

Depressions housing legs (l.d) are depressed zones concave-arc shaped, directing slightly obliquely, situated externally to epimeric zone (indicated by Grandjean 1950). At the moment of leg-folding, this zone partially conceals legs. Evidently the paraxial side is the unique protected zone. In this instance, depressions l.d show a complementary association with umbrella-shaped setae situated on the antiaxal surface of legs and femurs.

During leg-folding, tarsus and tibia are directed towards trochanter and femur, and the genu functions as a hinge ( Fig. 4 View FIG A-D). Legs are housed in depressions and large umbrella-shaped setae cover the entire antiaxial side. This protection mechanism is very simple, but effective. Umbrella-shaped epimeric setae assisting with camouflage, resulting in legs being very difficult to detect in specimens with all setae intact.

In Figure 4 View FIG A-C, legs are not completely folded, permitting an understanding of positioning of legs. When fully folded, as seen in several cases, only extremities of long setae and the part of solenidia are visible (see Discussion).

REMARKS

Observation by optical microscopy is difficult due to dorsal and ventral covering of specimens by umbrella-shaped setae, which have to be removed for study.

Legs are challenging to study, because in all specimens legs were situated in leg-housing depressions, and obtaining whole legs by dissection with all setae intact was almost impossible.Preparations containing lactic acid resulted in margins of umbrella-shaped setae becoming torn. Setal shapes were similar in all cases, but sizes varied; in several cases, during observation of setae slightly from the side, they appeared to be fan-shaped structures.

Neotrichous setae are small in relation to others. Determining the number of setae affected by neotrichy necessitated removal of all, and observing insertions. A similar situation arose on the epimeric zone where all setae were removed and insertions studied.

One of the particularities of B. anneae n. gen., n. sp. is the “leg-folding process” involving umbrella-shaped setae on femora, and the leg housing depressions situated in the lateroventral zone. Processes observed in Bovicarabodes and Bedoslomannia are very different and involve dissimilar structures and strategies.

Grandjean (1950: 101) indicated that the leg housing depression, “Niches latérales pour les pattes”, permits receiving of legs when the specimen retracts them against the body. This observation by Grandjean is very important, but detailed studies on this aspect of Lohmanniidae were not made ( Norton 2010 cited in page 9 and 14 this structures with the term “pedofossae”, as a characteristic of Lohmanniidae ). Our initial observations created the impression that these mites had no legs as none were visible. The problem was that specimens were covered by umbrella-shaped setae and soil particles, together impeding adequate observation. Soil particles were eliminated and legs were found completely concealed behind umbrellashaped setae on legs, and legs retracted in the leg housing depressions. Epimeric umbrella-shaped setae contributed to the protection mechanism.

On legs I and II we found three umbrella-shaped setae and on III and IV only one. In both cases, when legs are retracted to their maximum, only the apical zone of the longest setae and the solenidia are partially visible. Femoral shape and the number of umbrella-shaped setae vary among legs I-IV, possibly related to the larger number of sensorial organs to protect (in an evolutionary sense).

MNHN

Museum National d'Histoire Naturelle

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