Zerconella (Zerconella) balkanica, Ujvári & O, 2013

Ujvári, Zsolt & O, Published, 2013, Zerconella (Zerconella) balkanica sp. nov., a new species of Zerconidae (Acari: Mesostigmata) from central Albania, Turkish Journal of Zoology 37 (6), pp. 669-675 : 670-672

Zerconella (Zerconella) balkanica sp. nov.

Type material. Holotype: female: E-2705 – Albania, Mat district , Dejë Mountains , sidestream of the Varoshit stream along the road to Lurë area, leaf litter from beech patch, 1215 m a.s.l., 41°39.824′N, 20°11.720′E, 19.05.2010, leg. Fehér, Z., Murányi, D., & Ujvári, Zs. (deposited in HNHM) . Paratypes: 1 female and 3 males, locality and date as for the holotype (1 female and 1 male deposited in CNC; 2 males deposited in HNHM) .

Diagnosis. J setal row only with 3 pairs of setae. Setae J5 elongate, situated in the central area of opisthonotum, directly next to each other. Lateral pair of dorsal cavities twice as large as central cavities. Podonotal setae z3, s5, and r3 and opisthonotal setae Z4–5 and S3–5 stronger and markedly longer than other dorsal setae.

Description of female. Length of idiosoma: 323–328 µm; width: 204 µm (n = 2).

Dorsal side ( Figure 1a ). Podonotum with 22 pairs of setae (j1–6, z2–6, s1–6, and r1–5). Each podonotal seta smooth and needle-like. Setae z3, s5, and r3 elongate, expanding beyond margins of idiosoma, other setae of the shield short. Podonotal gland openings not conspicuous. Surface of podonotum with weakly developed reticulate pattern and muscle scars.

Opisthonotum with 19 pairs of setae, J2–3, J5, Z1–5, S1–5, and R 1–6. Setae J1 and J4 absent. Setae J2–3, Z1–3, and S1–2 similar in appearance, short, smooth, and needle-like, none of them reaching the base of the following one in the series. Setae J5 3–4 times longer than short opisthonotal setae, situated in the central area of opisthonotum, directly next to each other, not reaching the line of dorsal cavities. Setae Z4 and S3–4 strong, markedly elongate, each reaching beyond margins of idiosoma. Setae Z5 similar in appearance to J5, situated 110 µm apart. Marginal R-setae short, smooth and needle-like. Length of opisthonotal setae and distances between their insertions as in the Table. Glands gdJ4 (Po3) situated on line connecting J5 and Z4, other opisthonotal glands not conspicuous. Anterior half of opisthonotal surface covered by weakly developed reticulate pattern, posterior half smooth. Posterodorsal cavities strongly sclerotized, ring-like, with undulate margins, lateral pair twice as large as central pair ( Figure 1b ).

Ventral side ( Figure 1c ). Tritosternal laciniae divided into 2 branches, both of these subdivided distally into 2–3 marginally serrate branches. Peritrematal shields posteriorly truncate at level of setae S1, posteriorly separated from podonotal shield by a triangular, weakly sclerotized slit. Ornamentation of peritrematal shields weakly developed, a fine reticulation of longitudinal lines visible. Peritremes ( Figure 2a ) short, stigmata situated at level of central area of the fourth coxae, distal end reaching only the posterior part of the third coxae. Chaetotaxy of ventral shields typical for genus Zerconella . Sternal shield 70 µm long and 51 µm wide at the level of setae st2, with nearly straight posterior margin and weakly developed reticulate ornamentation. Adgenital platelets with 2–2 openings of gv2, postgenital sclerites present. Ventrianal shield with short, smooth, needle-like preanal and adanal setae, setae Zv1 present. Postanal seta (pa) and setae Jv5 uniform, smooth and needle-like, 1.5–2 times longer than preanal and adanal setae (ad). Anal valves with vestigial euanal setae. Glands gv3 situated posterolateral to adanal setae, on line connecting setae Jv4 and postanal seta. Anterior surface of ventrianal shield covered by tile-like pattern to level of Jv3-Zv3-Zv4.

Gnathosoma ( Figure 2b ). Situation of hypostomal and subcapitular setae typical for the family. Setae h1–2 elongate, smooth. Setae h3 shorter than h1, smooth, h4 as long as h1–2, marginally serrate. Corniculi hornlike, internal malae with a pair of bifurcate anterocentral branches and with smooth margins. Chelicerae relatively slender, fixed digit with 6 teeth, movable digit with 4 teeth. Epistome of Parazercon - type ( Figures 2c and 2d ).

Description of male ( Figures 3a and 3b ). Length of idiosoma: 247–258 µm; width: 150–156 µm (n = 3). Chaetotaxy, poroidotaxy, and sculptural pattern of dorsal, ventrianal, and peritrematal shields similar to those of female. Length of opisthonotal setae and distances between their insertions as in the Table. Sternigenital shield entire, 5 pairs of sternigenital setae present. Postgenital sclerites not visible. The triangular slit separating posterior ends of peritrematal shields from podonotal shield less expressed than in female. The slit between lateral parts of ventral shield and opisthonotal shield narrower than in female. Each character of gnathosoma (epistome of males shown in Figures 3c–3e ) similar to those of female, but terminal part of fixed digit of chelicerae bifurcate.

Etymology. The name of the new species refers to the Balkan Peninsula, the geographic area where the specimens were collected.

Differential diagnosis. The new species belongs to the subgenus Zerconella (Zerconella) by the following characters: caudodorsal region without elevations; surface of dorsal shields smooth; some dorsal setae and all marginal setae short. Zerconella (Zerconella) balkanica sp. nov. is very similar in appearance to the other species of the subgenus Zerconella (Zerconella) leitnerae Willmann, 1953 . The new species, however, can easily be distinguished from the latter by the absence of setae J4, the position of setae J5 [situated in the posterior half of opisthonotum, reaching beyond the line of dorsal cavities in Z. (Z.) leitnerae , located in the central area of opisthonotum, not reaching the line of dorsal cavities in Z. (Z.) balkanica sp. nov.], and the size of dorsal cavities [approximately uniform in Z. (Z.) leitnerae , lateral cavities twice as large as central cavities in Z. (Z.) balkanica sp. nov.].

Remarks. Zerconella (Zerconella) balkanica sp. nov. obviously lacks 2 pairs of J-setae, but the question arises: which are the missing pairs? As Zerconidae generally have 5 pairs of J-setae, and absence of any of these pairs is quite rare within the family (it can serve as a basis for classification, as well), it is very important to find out which of the 5 pairs do not develop in this species. According to Lindquist and Moraza (1998), those setae that appear in the larval stage are the most conservative (they are most likely to appear), while setae appearing in the protonymphal stage have a higher chance of not developing, and setae appearing in the deutonymphal stage are those that are absent in most of the species with incomplete chaetotaxy. On the basis of the chaetotaxy system of Lindquist and Moraza (1998), setae J2–5 are larval setae, while the J1 pair appears in the protonymphal stage; therefore, the latter has the greatest chance to be absent on adult specimens in each Zerconella species [as was indicated in the case of other Zerconella species, as well ( Ujvári, 2010b)]. The appearance of J-setae of Zerconella (Zerconella) leitnerae is very similar to that of J-setae of Z. (Z.) balkanica sp. nov. As a conclusion of the previous facts, both species lack setae J1, but Z. (Z.) balkanica sp. nov. also lacks one pair of J2–5. Setae J2–3 of the new species seem to be identical to those of Z. (Z.) leitnerae by their similar position; therefore, the missing pair must be J4 or J5. While the last pair of the J-series of Z. (Z.) balkanica sp. nov. is similar in appearance to J5 of Z. (Z.) leitnerae , most probably these setae are also identical regarding their origin, even if these elongate setae are shifted to the central part of the opisthonotum in the new species. Hence, setae J4 must be the other absent pair.

Figures

Figure 1. Zerconella (Zerconella) balkanica sp. nov. female: a) dorsal view of idiosoma; b) dorsal view of posterior region of opisthonotum, with the posterodorsal cavities; c) ventral view of idiosoma.

Figure 2. Different structures of Zerconella (Zerconella) balkanica sp. nov. female: a) peritreme; b) ventral view of gnathosoma; c and d) epistome.

Figure 3. Zerconella (Zerconella) balkanica sp. nov. male: a) dorsal view of idiosoma; b) ventral view of idiosoma; c, d, and e) epistome.