Gaeolaelaps zanzibarensis, Joharchi & Halliday & Khaustov & Ermilov, 2018

Joharchi, Omid, Halliday, Bruce, Khaustov, Alexander A. & Ermilov, Sergey G., 2018, Some soil-inhabiting mites from Zanzibar (Acari: Laelapidae), Zootaxa 4514 (1), pp. 23-40 : 25-26

Gaeolaelaps zanzibarensis sp. nov.

( Figs 1–17 )

Type material: Holotype, female, Tanzania, Zanzibar, forest litter, 06°16'S, 039°25' E, 8 m. a.s.l., 2 February 2018, coll. S.G. Ermilov, A.A. Khaustov (in TUMZ); paratypes: six females, same data as holotype (four in TUMZ, two in ANIC).

Description. Female (n= 7 specimens)

Dorsal idiosoma. Dorsal shield oval shaped, 520–550 long, 330–340 wide, covering entire idiosoma, with weak reticulation, more distinct in opisthonotal and lateral regions ( Figs 1 , 10 ). Dorsal shield with 39 pairs of long setae, 22 pairs on podonotal region (j1–6; z1–6; s1–6; r2–5) and 17 pairs on opisthonotal region (J1–5; Z1–5; S1–5; and two pairs of Zx), unpaired supernumerary seta Jx absent, all setae curved and uniform in length (35–50) and thickness except j1 (28–31), z1 (24–30); Z5 (50–55) and some setae on podonotal region with 2–4 minute barbs (J3–J5, Z4, Zx, Z5, S5, see Figs 1 , 10 ). Shield with 16 pairs of discernible pore-like structures, six on podonotum (id1, id2, id4, id5, gd1, gd5, see Fig. 1 ) and ten on opisthonotum (idm1–idm5, idx, is1, idl1, idl3, idl4, see Fig. 1 ).

Ventral idiosoma ( Figs 2 , 11, 12, 13 , 17 ). Tritosternum with paired pilose laciniae (40–50), columnar base 30– 35 long × 10–12 wide; pre-sternal plates well sclerotised, with two conspicuous transverse lines ( Figs 2 , 11 ). Sternal shield (length 127–133) narrowest between coxae II (96–105), widest between coxa II-III (147–154), with almost straight posterior margin; with three pairs of simple and subequal sternal setae, st1 33–35, st 2 30–32, st 3 30–32, and two pairs of poroids, iv1 slit-like and iv2 sub-oval, adjacent to setae st1 and between st2 and st3, respectively; reticulated antero-laterally, median region smooth ( Figs 2 , 11, 12 ); lateral margins alongside coxa II– III fused with endopodal plates. Metasternal platelets absent, one pair of simple metasternal setae st4 (29–32) and pore-like iv3 inserted on soft cuticle posterior to sternal shield; endopodal plates III/IV elongate, narrow, curved and free from sternal shield. Genital shield elongate, rounded posteriorly, expanded just posterior to genital setae, width 126–132 and length 222–225. Surface reticulated with irregular longitudinal lines in anterior half, enclosing nine polygonal cells in posterior part, shield bearing smooth genital setae st 5 (28–32) on the edges ( Figs 2 , 11 ). Paragenital poroids (iv5) located on soft cuticle lateral to shield near st 5. Two pairs of minute paragenital platelets present between posterolateral margins of genital shield and metapodal platelets. Anal shield subtriangular, length 85–90, width 101–110, bearing three sub-equal, simple and smooth circumanal setae, post-anal seta (22–25), and a pair of para-anal setae (19–22), its anterior half with lineate ornamentation and a pair of lateral pores (gv3); cribrum small, without extensions. Soft opisthogastric cuticle surrounding genital and anal shields with one pair of sub-oval metapodal plates (35–37 long × 7–10 wide), six pairs of setae (Jv1–Jv3, Zv1–Zv 3) and five pairs of discernible pore-like structures including iv3 and iv5; all setae uniform in length (20–25) and thickness, except Zv3 shorter (14–16) ( Figs 2 & 12 ). Peritreme short, extending to mid-level of coxa II ( Fig. 13 ), peritrematal shield wide, free from exopodal shields, each shield bearing five discernible pore-like structures, a poroid ip at level of coxa II and a gland pore gp at level of coxa III, two poroids ip and a gland pore gp on post-stigmatic section and also a small pore-like structure within peritreme at level of coxa III ( Figs 11, 13 , 17 ); anterior part of shield fused with dorsal shield.

Gnathosoma ( Figs 3, 4, 5 , 14, 15, 16 ). Hypostome with three pairs of hypostomal setae, h1 35–38, h 2 22–25, h 3 30–35, and a pair of palpcoxal setae (pc) (32–34). Deutosternal groove wide, with six transverse rows of 12–20 denticles, corniculi horn-like and parallel to each other, almost reaching mid-level of palp femur ( Figs 3 , 16 ). Palp chaetotaxy normal: trochanter 2, femur 5, genu 6, tibia 12, tarsus 15, all setae smooth and needle-like except al1 and al2 on palp genu apically spatulate ( Fig. 15 ); palp tarsal claw two-tined ( Fig. 15 ). Internal malae with a pair of pointed lobes, laterally coarsely fimbriate; labrum with spiculate surface. Anterior edge of epistome arched, strongly denticulate ( Figs 4 , 14 ). Fixed digit of chelicera with five teeth of various sizes, a setaceous pilus dentilis, dorsal cheliceral setae short. Arthrodial brush present at base of movable digit, movable digit with two teeth, cheliceral lyrifissure distinct ( Fig. 5 ).

Legs ( Figs 6–9 ).Tarsi I–IV each with a pair of claws and pulvillus. Legs II (333–336) and III (297–299) shorter than legs I (452–460) and IV (460–480). Chaetotaxy normal for free-living Laelapidae : Leg I ( Fig. 6 ): coxa 0 0/1 0/ 1 0, trochanter 1 0/2 1/1 1, femur 2 2/1 3/3 2, genu 2 3/2 3/1 2 (pl1 and pl2 longer than the other dorsal and lateral setae, Fig. 6 ), tibia 2 3/2 3/1 2 (pl1 and pl2 longer than the other dorsal and lateral setae, Fig. 6 ). Leg II ( Fig. 7 ): coxa 0 0/1 0/1 0, trochanter 1 0/1 1/2 1, femur 2 3/1 2/2 1 (al1 and al2 longer than the other dorsal and lateral setae), genu 2 3/1 2/1 2 (ventral setae thickened, Fig. 7 ), tibia 2 2/1 2/1 2 (ventral setae thickened, Fig. 7 ). Leg III ( Fig. 8 ): coxa 0 0/1 0/ 1 0, trochanter 1 0/1 0/2 1, femur 1 2/1 1/0 1 (pd thickened, Fig. 8 ), genu 2 2/1 2/1 1 (al1 longer than the other dorsal and lateral setae, ventral setae thickened), tibia 2 1/1 2/1 1 (ventral setae thickened, Fig. 8 ). Leg IV ( Fig. 9 ): coxa 0 0/1 0/0 0, trochanter 1 1/1 0/1 1, femur 1 2/1 1/1 0 (pd strongly thickened), genu 2 2/1 3/ 0 1, tibia 2 1/1 3/1 2 (ventral setae strongly thickened, Fig. 9 ). All setae fine and needle-like unless otherwise noted in parentheses above. Tarsi II–IV with 18 setae 3 3/2 3/2 3 + mv, md, all setae simple and needle-like; setae al1, pl1 and pd2 on tarsus of leg II ( Fig. 7 ) and all ventral setae slightly thickened; setae pd2–3, al2–3 on tarsus IV longer than the other setae on this segment. All pre-tarsi with a well-developed ambulacral stalk, a pair of claws and three rounded pulvillar lobes, projecting well beyond claws.

Insemination structures: Not seen, apparently unsclerotised.

Male. Unknown.

Etymology. The specific name is derived from the type locality.

Differential diagnosis. In the key provided in Nemati & Mohseni (2013) to species with short peritremes, the new species will run to couplet 16, where it is unique in having 39 pairs of short dorsal shield setae, including two pairs of Zx setae, genital shield length/width nearly 2:1, iv2 pore-like, J2 located behind J1, palp tarsal claw 2-tined and lateral margins of genital shield not parallel (shared with Gaeolaelaps koseii ( Hafez et al., 1982) and G. similisetae (Karg, 1965)) , but with a much larger body size and wider genital shield (body size 443 long 275 wide in G. koseii and 440–460 long 240–260 wide in G. similisetae ). Additional characters separating these species include the shape of dorsal shield setae and the size of peritrematal shield (curvate and with minute 2–4 barbs on podonotal region in G. zanzibarensis , versus without any barbs and smooth in G. similisetae and G. koseii ; peritrematal shield wide in G. zanzibarensis , versus narrow in G. similisetae and G. koseii ).

Figures

FIGURES 1–5. Gaeolaelaps zanzibarensis sp. nov., female. 1, dorsal idiosoma; 2, ventral idiosoma; 3, subcapitulum; 4, epistome; 5, chelicera.

FIGURES 6–9. Gaeolaelaps zanzibarensis sp. nov., female. 6, leg I; 7, leg II; 8, leg III; 9, leg IV.

FIGURES 10–13. Gaeolaelaps zanzibarensis sp. nov., female. 10, general view dorsally; 11, general view ventrally; 12, sternal shield; 13, general view of stigma, peritreme and peritrematal shield.

FIGURES 14–17. Gaeolaelaps zanzibarensis sp. nov., female. 14, epistome; 15, palp and tarsal claw; 16, subcapitulum; 17, stigma and post peritrematal shield.