Coecobrya cavIcta

Nilsai, Areeruk, Jantarit, Sopark, Satasook, Chutamas & Zhang, Feng, 2017, Three new species of Coecobrya (Collembola: Entomobryidae) from caves in the Thai Peninsula, Zootaxa 4286 (2), pp. 187-202 : 198-200

Coecobrya cavIcta Nilsai & Zhang sp. nov.

Figs 5 , 43–55 , Tables 2–3

Type. Holotype: female on slide, Thailand: Satun Province: Khuan Don District: Ton Din cave, 6.72636°N, 100.16249°E, altitude 115 m, 8.ix.2016, S. Jantarit and A. Nilsai leg. (collection #THA_SJ_STN08), deposited in PSU-NHM.

Description. Body 1.72 mm. Body whitish in alcohol ( Fig. 5 ).

Antennae 2.67 times as long as cephalic diagonal. Antennal segment ratio as I: II: III: IV = 1: 1.48: 1.52: 2.39. Smooth spiny mic at base of antennae: three dorsal and three ventral on Ant. I, one internal, one external and one ventral on Ant. II. Long smooth straight chaetae present on the ventral side of Ant. I. Distal part of Ant. II and Ant. III organ not clearly seen.

Eyes absent. Prelabral and labral chaetae 4/5, 5, 4, all smooth; three median chaetae of the first and the second rows longer than lateral ones ( Fig. 43 ). Clypeal chaetae smooth but their arrangement unclear. Dorsal cephalic chaetotaxy with four antennal (An), three median (M) and eight sutural (S) mac; Gr. II with four mac ( Fig. 44 ). Mandibles with 4+5 (4 left, 5 right) large apical teeth. Subapical chaeta of maxillary outer lobe thicker than apical one; three smooth sublobal hairs on maxillary outer lobe ( Fig. 45 ). Hypostomal chaetae h1 and h2 curved and subequal ( Fig. 46 ). Lateral process of labial palp as thick as normal chaetae, with tip beyond apex of labial papilla ( Fig. 47 ). Labial chaetae as mrel1l2, all smooth; r, X, X2, X4, and a chaeta between H2 and H3 smooth and minute. Chaetae along cephalic groove 11, of which 3–4 smooth and two minute ( Fig. 48 ).

Trochanteral organ with 15–16 smooth spine-like chaetae; eight in arms and 7–8 between them ( Fig. 49 ). Partial inner differentiated tibiotarsal chaetae ciliate with ciliations not closely appressed to axis. Tibiotarsi distally with 10 chaetae in a whorl. Unguis with two paired inner teeth, unequal and 0.28 distance from base; unpaired tooth absent. Unguiculus lanceolate with outer edge serrate; the basal tooth clearly seen but the distal teeth extremely minute and often indistinct. Tenent hairs pointed ( Fig. 50 ). Abd. IV 4.41 times as long as Abd. III along dorsal midline. Ventral tube not clearly seen. Furcula without smooth chaetae. Distal part of manubrium ventrally with 13+13 ciliate chaetae ( Fig. 51 ). Manubrial plaque with two pseudopores and four ciliate chaetae ( Fig. 52 ). Distal smooth part of dens 0.90 times as long as mucro. Mucro falcate with a long basal spine, nearly reaching the tip of the apical tooth ( Fig. 53 ).

Th. II with three (m1, m2, m 2i) medio-medial, four (m4, m4p, m 4i, m 4i 2) medio-sublateral and 30–31 posterior mac; ms inner to sens; p5 as mac. Th. III with 35 mac; a 4i 2, m 5i, a 6i and m6ai as mac ( Fig. 54 , Table 2). Abd. I with seven (a2, a3, m2–4, m 2i, m4p) mac; sens posterior to ms. Abd. II with 4+5 (a2, a3, m3, m3e, m3ep) central and one (m5) lateral mac; a3 as mic on left side. Abd. III with one (m3) central and three (am6, pm6, p6) lateral mac ( Fig. 55 ). Abd. IV with 7+9 central (I, M, A5, A5p, A6, B2–5) and 11 lateral mac (D3, E2–4, E2p, Ee8, Ee10, F1–3, F1p); B2 and B3 as mac on left side ( Fig. 56 ). S-chaetae formula: 2+ms, 2/1+ms, 2, 2,?, 3; ps on Abd. IV 1 /3 length of others.

Ecology. This species was found in a dark, humid cave near a stream bank, without bat guano.

Etymology. Named after the Latin word cavi- ("cave") + victa ("living").

Remarks. Coecobrya cavicta sp. nov. can be separated from other Coecobrya species by the combination of abundant posterior mac on dorsal head, labial chaetae r and six smooth and minute postlabial chaetae, two inner teeth on unguis, serrate outer edge on unguiculus, 13+13 chaetae on distal part of manubrium ventrally, four median-lateral mac on Th. II, five or four mac on Abd. II, and nine or seven central and 11 lateral mac on Abd. IV. It differs from closely related species in absence of unpaired tooth on unguis and four medio-sublateral mac on Th. II ( Table 3).

Figures

FIGURES 2 – 5. Habitus: 2, Coecobrya chumphonensis sp. nov.: 3, Coecobrya polychaeta sp. nov.; 4, Coecobrya cf. polychaeta sp. nov.; 5, Coecobrya cavicta sp. nov. Scale bar: 1 mm.

FIGURES 43 – 54. Coecobrya cavicta sp. nov. 43, labrum; 44, dorsal cephalic chaetotaxy; 45, maxillary outer lobe; 46, hypostomal chaetae; 47, lateral process of labial palp; 48, labial and postlabial chaetae; 49, trochanteral organ; 50, hind claw; 51, distal part of manubrium ventrally; 52, manubrial plaque; 53, mucro; 54, thoracic chaetotaxy.

FIGURES 55 – 56. Abdominal chaetotaxy in Coecobrya cavicta sp. nov. 55, Abd. I – III; 56, Abd. IV.