Sinella tiani, Zhao, Lina & Zhang, Feng, 2016

Zhao, Lina & Zhang, Feng, 2016, New cave species of Sinella Brook, 1882 from China (Collembola: Entomobryidae), Zootaxa 4161 (4), pp. 523-541 : 537-539

Sinella tiani sp. nov.

Figs 3 , 71‒88

Types. Holotype: female on slide, China: Guizhou Province: Wuchuan: Fengle town: Cunchuan cave, 107.833°E, 28.324°N, altitude 800 m, 30.vii.2015, Mingyi TIAN and Jingli CHENG leg . (collection # 15cave5). Paratypes: five females on slides and 6 in alcohol, same data as holotype. All material deposited in NJAU .

Description. Body length up to 2.6 mm. Body whitish in alcohol ( Fig. 3 ).

Antennae 2.1–2.2 times as long as cephalic diagonal. Antennal segments ratio as I: II: III: IV = 1: 1.6–2.0: 1.8–2.2: 2.8–3.2. Smooth spiny mic at base of antennae: 3 dorsal, 3 ventral on Ant. I, 1 internal, 1 external and 1 ventral on Ant. II. Smooth straight long chaetae on antennae absent. Thick, short S-chaetae 2(4) dorsal on distal Ant. II ( Fig. 71 ). Ant. III organ with chaetae 2 and 3 paddle-like, chaeta 8 dagger-like ( Fig. 72 ). Ant. IV subapical organ distally slightly expanded.

Eyes absent. Labral papillae absent. Prelabral and labral chaetae 4/ 5, 5, 4, all smooth; median three chaetae of the first row longer than others. Clypeal chaetae about 14, all ciliate ( Fig. 73 ). Dorsal cephalic chaetotaxy with 4 antennal (An), 4 median (M) and 8 sutural (S) mac; Gr. II with 4 mac ( Fig. 74 ). Mandibles with 4+5 teeth. Subapical chaeta of maxillary outer lobe subequal to apical one; 3 smooth sublobal hairs on maxillary outer lobe ( Fig. 75 ). Lateral process of labial palp as thick as normal chaetae, with tip beyond apex of labial papilla ( Fig. 76 ). Labial chaetae as mrel1l2, all smooth; ratio of r to m 0.6–0.7; chaetae X, X2‒4 as smooth mic. Chaetae along cephalic groove 7–9, anterior three smooth and others ciliate ( Fig. 77 ).

Trochanteral organ with 21–32 smooth spiny chaetae; 9–12 in arms and 11–20 between them ( Fig. 78 ). Inner differentiated tibiotarsal chaetae moderately ciliate with ciliations closely appressed to axis. Tibiotarsi distally with 11 ciliate chaetae in a whorl. Unguis with minor inner paired teeth at 1/6 from base. Unguiculus outer edge with a minor tooth. Tenent hairs smooth and pointed, much shorter than unguiculus ( Fig. 79 ). Abd. IV 3.7–4.4 times as long as Abd. III along dorsal midline. Ventral tube anteriorly with 8–10 ciliate chaetae on each side ( Fig. 80 ); posteriorly with about 16‒23 chaetae, apical four smooth and others ciliate ( Fig. 81 ); each lateral flap with 7‒8 smooth chaetae. Manubrium without smooth chaetae. Distal part of manubrium ventrally with 6+6 ciliate chaetae ( Fig. 82 ). Manubrial plaque with 2 pseudopores and 3 (rarely 4 or 5) ciliate chaetae ( Fig. 83 ). Distal smooth part of dens 0.6–0.7 times as long as mucro. Mucro bidentate with basal spine short, its tip reaching apex of subapical tooth ( Fig. 84 ).

Th. II with 3–5 (m1, m2, m 2i, m 2i 2, m2e) medio-medial, 3 (m4, m 4i, m4p) medio-lateral, 21–26 posterior mac, 1 ms and 2 sens; ms internal to sens; m 2i 2 and m2e often absent; mac p2ep2 rarely absent; p4 rarely as mac. Th. III with 18–22 mac and two lateral sens; mac p2ep rarely present ( Fig. 85 ). Abd. I with 7–8 mac, m 4i often absent, 1 ms and 1 sens; sens internal to ms. Abd. II with 2 (m3, m3e) central, 1 (m5) lateral mac and two sens.

Abd. III with 1 (m3) central, 2 lateral (pm6, p6) mac, 1 ms and two sens ( Fig. 86 ). Abd. IV with 6 central (M, I, A5–6, B4–5), 6 lateral mac (F1, E2, E2p, E3–4, D3) and about 11 sens; B6 often as mesochaeta ( Fig. 87 ). Abd. V with 3 sens ( Fig. 88 ).

Ecology. In aphotic zone of cave.

Etymology. Named after Prof. Tian, who collected the animals.

Remarks. This new species is characterized by tiny mic X and X2–4 on ventral side of head, unguiculus with a minor outer tooth, and 6+6 central mac on Abd. IV. It is closest to S. fuyanensis in pointed tenent hairs, short mucronal spine, smooth chaetae X, X2 and X4 posterior to labium, and chaetotaxy of Abd. I‒ IV, but differs from the latter in claw structure and eye number.

Figures

FIGURES 1 – 3. Habitus: 1, Sinella liuae sp. nov.; 2, Sinella hunanica sp. nov.; 3, Sinella tiani sp. nov.

FIGURES 71 – 84. Sinella tiani sp. nov.: 71, Ant. II organ, arrow indicating the chaeta may be absent; 72, Ant. III organ; 73, clypeal chaetae; 74, dorsal cephalic chaetotaxy; 75, maxillary outer lobe; 76, lateral process of labial palp; 77, labial and postlabial chaetae; 78, trochanteral organ; 79, hind claw; 80, anterior face of ventral tube; 81, posterior face of ventral tube; 8 2, distal part of manubrium ventrally; 83, manubrial plaque; 84, mucro.

FIGURES 85 – 88. Tergal chaetotaxy in Sinella tiani sp. nov.: 85, thorax; 86, Abd. I – III; 87, Abd. IV; 88, Abd. V.