Brasilacarus cocaris Vázquez, Araújo & Feres., 2015

Vázquez, Ma. Magdalena, Araújo, Marcel Santos De & Feres, Reinaldo José Fazzio, 2015, Brasilacarus cocaris (Acari: Opilioacaridae), a new genus and species from Amazonia, Brazil, Zootaxa 3915 (3), pp. 375-389 : 377-382

Brasilacarus cocaris Vázquez, Araújo & Feres. n. sp.

( Figs. 2–23 )

Species diagnosis: As for genus. In addition, sexual dimorphism present, with females bigger than males and having more setae on hypostome, sternogenital region and dorsal shield. Movable digit of chelicera with 3 small ventral denticles. Males with less subcapitular setae (10) than females (12). Pregenital and genital setae in male pointed and serrated, with 5 on pregenital area and 9 on genital area, emerging from a small raised patch. Females with 3 small blunt pregenital setae on a small raised patch above genital opening and 11 thick, pointed eugenital setae inside and under genital opening, genital setae absent.

Description. Based on observations on 2 males, 2 females, 1 TN and 2 DN. Larva and protonymph unknown. Gnathosoma . Chelicera ( Figs. 2–4 ). Males and females with 3 fine, long serrated setae on fixed digit. Basal segment with 1 seta, lightly barbed on one side only. Lyrifissures not visible. Movable digit with 3 small ventral denticles ( Fig. 4 ).

Subcapitulum ( Figs. 5–6 ). All 4 pairs of paralabial setae present in adults: pl1 small, conical; With’s organ (pl2) large, membranous, discoid, with 2 small, curved branches holding its hyaline part; rutellum (pl3) with 1 row of 5 teeth, inserted dorso-laterally; pl4 indistinct; 4 circumbuccal (cb), 10–12 median and subcapitular (vm, lvm, ldm, vp, lvp) setae on adults. Males 10 setae and females 12. Lateral lips with distinct canals.

Palps ( Figs. 7–14 ). Trochanter with 6 r setae; femur with 7–10 p and 10–12 r - type setae; genu with 13–15 p and about 40–45 r setae. Lyrifissures not observed on genu or femur. Tibia with 35–40 r setae ( Fig. 7–8 ) divided in 2 differentiated groups; one group comprising 17–20 thin, serrated, pointed setae; other group comprising 14–18 large, thick, strongly serrated, curved setae, seeming protecting tarsal setae. Palp tarsus setation in adults with 5–7 sm setae, 3 s setae, 13–16 ch setae, 8 d (leaf-like setae)( Fig. 14 ), 3 v 1 and 5– 6 v2 (6 on females, 5 on males), unique group of 5–6 membranous, thick, shiny setae with whip-like tip, emerging from a rugose surface patch ( Fig. 13 ). Pretarsus with a pair of well-developed sessile claws with 2 small denticles on internal side of claw ( Fig. 12 ). Sexual dimorphism present, females with more setae on palp (tibiotarsus), 18 (females) and 16 (males). Palps of immature stages were lost.

Idiosoma. Color (observed in alcohol preserved specimens). Dark blue and purple with usual banding pattern on legs and idiosoma.

Dorsum. Anterior dorsal shield in adults with 2 pairs of eyes and 86 plumose setae in males and 137 in females ( Figs. 15–16 ), based on 2 females and 2 males. Lyrifissures not visible.

Tritosternum. Each process with 2 setae, distal seta smaller than proximal seta. Proximal seta surpassing tip of distal seta. Proximal seta serrate, thick at base, with whip-like tip.

Preanal segment ( Figs. 17–18 ) with 1 dorsal, 2 ventral setae located closer to midline of body (in other opilioacarid species, these setae are located more laterally). Anal valves with 16 stout blunt ribbed setae on females, 10 setae on males, 8 setae on TN and 6–7 on DN. Based on 2 M, 2 F, 1 TN and 2 DN.

Sternogenital region ( Figs. 19–20 ). Sternal verrucae on both adults with 2–3 barbed, tapering setae plus 1 distinctly longer, barbed, tapering setae (st1). Remaining sternal area with 5–6 large barbed blunt setae in female and 2 in male, plus, in both, 2 pairs of barbed, tapering setae (st2 and st3). Pregenital capsules each with 6–7 large, stout ribbed setae in female and 4 in male, plus, in both, 1 long, tapering seta (st5). Pregenital area in females with 3 small blunt thick setae emerging from a rugose patch and 11 eugenital setae, which are large, serrated, with acute tips and located below genital opening, on less sclerotized cuticle. Pregenital setae located up genital opening, genital setae down genital opening, eugenital setae always inside genital opening but not on ovipositor, see Figs. 21–29 . Male pregenital area with 5 small serrated setae with acute tips, plus 9 small serrated acute setae in genital area. Both groups of setae emerge from rugose patches.

Ovipositor ( Figs. 30–31 ). Comprising 1 pair of large, thick, curved spines in median part, and two pairs of membranous projections with numerous serrations, emerging from apical region. Several smaller membranous projections emerge at sides of spines. Central part of ovipositor with a pair of small glands or orifices connected to small ducts. Apical region of ovipositor funneling into a duct with 2 glands or sac-like structures, which move up and expand when ovipositor is evaginated.

One female has an evaginated ovipositor and was not dissected; it is thus possible to observe an egg emerging from the ovipositor through a wide gap of the genital opening ( Fig. 31 ). The ovipositor is surrounded by a thick and large channel which is connected with a pair of glands (possibly ovaries).

Male glands ( Fig. 32 ). With 2 pairs of glands, subequal in size, easily visible inside body under genital opening.

Legs. Most legs are missing, only 1 female had 1 leg III and 1 leg IV.

Measurements: Idiosomal length 1730–2042, width 1143–1258. Palp: trochanter 93–138; femur 186–202; genu 142–154; tibiotarsus 181–211. Rutellum: 106–113. Chelicera: movable digit 75–82; fixed digit 213–232; basal segment 166–201. Leg III: trochanter I 172, trochanter II 151, femur 443, genu 277, tibia 283, basitarsus 347, telotarsus 298, acrotarsus 107. Leg IV: trochanter I 281, trochanter II 254, femur 726, genu 402, tibia 513, basitarsus 502, telotarsus 398, acrotarsus 104.

Collection information. 2 M, 2 F, 1 TN and 2 DN, Holotype male. BRAZIL, Amazonas, Manaus, near Negro river and Taruma-Mirim stream, coll. Lehtinen, P., 10.IX.1983, litter of sparse terra-firme forest. Paratypes, BRAZIL, Amazonas, Manaus, near Negro river, Ponta Negra, coll. Lehtinen, P., 11.IX.1983, litter of palm forest.

Deposition of types. Holotype male at ZMT. Paratypes at ZMT and DZSJRP.

Etymology. The group of setae on the palp give the appearance of a crest (“cocar”, in Portuguese).

Figures

FIGURES 2 – 6. Brasilacarus cocaris n. sp. Lateral view of chelicera, 2, female, 3, male. 4, Detail of female chelicerae movable digit. Ventral view of subcapitulum, 5, female, 6, male.

FIGURES 7 – 10. Brasilacarus cocaris n. sp. Male tibiotarsus view, 7, ventral, 8, dorsal. Palp male view, 9, ventral, 10, dorsal. The brackets indicate the large palp tibia r setae.

FIGURES 11 – 14. Brasilacarus cocaris n. sp. 11, ventral view of male palp tarsus. 12, ventral view of tarsus claw. 13, detail of unique group of setae. 14, detail of d - type setae.

FIGURES 15 – 16. Brasilacarus cocaris n. sp. 15, dorsal view of female prodorsal shield. 16, dorsal view of male prodorsal shield.

FIGURES 17 – 18. Brasilacarus cocaris n. sp. 17, ventral view of female preanal segment. 18, ventral view of male preanal segment.

FIGURES 19 – 20. Brasilacarus cocaris n. sp. 19, ventral view of female sternogenital area. 20, ventral view of male sternogenital area.

FIGURES 21 – 22. Salfacarus antsirananensis, sternitogenital region. 21, Female (OSAL 007754); 22, Male (OSAL 007765). lt: long, tapering setae; ly: lyrifissure (different types); spg: pregenital; g: genital; eug: eugenital setae (Vázquez & Klompen, 2010).

FIGURE 30 – 32. Brasilacarus cocaris n. sp. Ventral view of female ovipositor, 30, invaginated, 31, evaginated in a process of laying an egg. 32, ventral view of male glands.