Anurida kyshyensis, Babenko & Nakamori, 2018

Babenko, Anatoly & Nakamori, Taizo, 2018, Two new littoral species of the genus Anurida Laboulbène, 1865 (Collembola, Neanuridae) from the Pacific coast of Asia, Zootaxa 4425 (3), pp. 575-581 : 575-577

Anurida kyshyensis sp. nov. ( Figs 1–11 )

Diagnosis. Blind whitish species of genus Anurida characterized by the presence of seven blunt sensilla on Ant.4 (S1– S4, S7–S9), oval PAO with about 20 lobes, mandibles with six teeth, maxilla with all three lamellae serrated, Th.2–3 with anterior position of p2-seta and few additional setae in lateral group, and 3+3 axial setae on tergum of Abd.4.

Type material. Holotype (male) on slide, North-East of Russia, Chukchi Peninsula , vicinity of Lavrentiya (Lawrence) settlement, thick wrack mat on stony beach [N 65.5281°, W 170.9809°], 0 9 vii 2013, O. Makarova & A. Babenko leg. ( MSPU) . Paratypes (female and 3 juveniles), same data as holotype ( MSPU) .

Description. Length without antennae 2.0–2.1 mm. General colour whitish with scarce granules of dark hypodermic pigment, especially conspicuous on dorsal side of head. Body shape typical of genus, rather slender and elongate, Abd.6 rounded, not truncate. Integument granulation more or less uniform and not especially coarse.

Ocelli absent. PAO elliptical consisting of about 20 densely parked lobes ( Fig. 1 ). Antennae clearly shorter than head, its shape typical of genus. Ant.4 with 3-lobed apical bulb, seven curved sensilla including additional one (S9) in lateral group, subapical ms and organite present ( Fig. 10 ). AO on Ant.3 typical, outer sensilla widely separated, small ms present ventrally. Ant.1–2 with 7(8) and 12 setae, respectively. Labral formula as 4/3-5-2, lateral pair of prelabral setae widely separated. Labium with 11 setae on each side including three setae on its apical part also armed with two small sensillar papillae. Mandibles ( Fig. 9 ) with three apical (third one set slightly out of line) and three larger basal teeth, most proximal one at least sometimes (seen in single individual) armed with additional thin teeth on outer margin. Maxillary capitulum with three strong teeth on main part and three clearly serrated lamellae, only lam.2 reaching well beyond tip of capitulum ( Fig. 8 ).

Most dorsal setae strong and finely ciliated, macrosetae straight and thick, almost spine-like, microsetae usually slightly curved but also thickened basally, sensilla smooth and thin, clearly differentiated from ordinary setae, about as long as macrosetae. Lateral microsensilla (ms) present only on tergum of Th.2. Dorsal chaetotaxy characterized by weak plurichaetosis, especially clear in adults ( Figs 6–7 ), but seen also in juveniles ( Figs 2–5 ). Main characteristics: tergum of Th.1 with 4+4 setae as a rule. Th.2–3 with macroseta p2 anteriorly to p1, sensilla (p3) practically at level with macrosetae p4, four setae (a3–a4, m3–m4) in dorsolateral group and two additional setae (m5’ and p5’) in lateral group usually present on one or both terga ( Fig. 6 ), sometimes even in juveniles ( Figs 2, 4 ). Terga of Abd. 1–3 in adults usually with 4+4 p-setae between sensilla (p4) due to presence of additional microseta p3’. Tergum of Abd.4 with macrosetae p 2 in unusual position and set almost in line with a1 and p1. Sterna of Th.1–3 without setae. Chaetotaxy of ventral tube variable: 8+8 and 4+ 6 in adults, 3–4 on each lobe in available juveniles. Furca remnant as narrow, longitudinal area without secondary granulation in anterior part of Abd.4 sternum.

Legs 1–3 chaetotaxy as following: upper subcoxae—1, 3, 4; lower subcoxae—0, 2, 2; coxae—3, 7, 7; trochanters— 6, 6, 6; femora—13, 12, 11; tibiotarsi—19, 19, 18 setae, respectively. Tibiotarsal setae of moderate length, A1 not clearly longer than other setae of A-whorl ( Fig. 11 ). Outer side of each lower subcoxa with roundish cuticular papilla ( Fig. 6 ). Unguis without inner or lateral tooth.

Etymology. The name of species is based on Kyshy, a local Eskimo name of Lavrentiya settlement.

Affinities. A. kyshyensis sp. nov. has an isolated position within blind species of the genus first of all due to specific chaetotaxy of Th. 1–3 terga. There are only 2 known species (both occur in the region under study), viz. A. martynovae Fjellberg, 1985 and A. similis Fjellberg, 1985 , characterized by anterior position of p2-setae on Th.2–3 but having sensilla p3 at a level with p1 and p4. Besides maxillary head of the former species is almost identical to that of A. kyshyensis sp. nov. as well as sensillar equipment of Ant.4 of A. similis and A. kyshyensis sp. nov. (both species have additional sensillum S 9 in the lateral group). Nevertheless, the new species can be easily distinguished from both A. martynovae and A. similis by peculiar chaetotaxy, first of all due to the presence of additional lateral setae on terga of Th. 2–3 and specific mutual position of axial setae on tergum of Abd.4.

There are also some similarity of A. kyshyensis sp. nov. and species of the hammerae -group of the genus represented common elements of local faunas in Eastern Asia. Thus, a chaetotic pattern of A. hammerae Christiansen, 1951 (regardless higher number of setae on tergum of Th.1 and position of sensilla p3 on terga of Th.2–3) is almost identical to that of A. kyshyensis sp. nov., including the presence of additional setae in the lateral group on Th.2–3 and 3+3 axial setae on Abd.4. Nevertheless A. hammerae is the only known species of the group with such chaetotaxy and it clearly differs from A. kyshyensis sp. nov. having ocelli, many additional sensilla on Ant.4., and different body shape with Abd.6 truncate and constricted at base.

Distribution. Known only from the type-locality.

Figures

FIGURES 1–11. Anurida kyshyensis sp. nov.: 1, PAO; 2, dorsal chaetotaxy of head and thorax, juvenile; 3, ibid, lateral view; 4, chaetotaxy of Abd.2–6, juvenile; 5, ibid, lateral view; 6, chaetotaxy of Th.1–2, adult, lateral view; 7, chaetotaxy of Abd.3–6, adult; 8, maxilla; 9, mandible; 10, Ant.3–4, dorso-lateral view; 11, distal part of leg 3. Scales: Figs 1–7—0.1 mm, 8–11—0.01 mm.