Coecobrya chumphonensis Zhang & Nilsai

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 : 188-194

Coecobrya chumphonensis Zhang & Nilsai sp. nov.

Figs 2 , 6–24 , Tables 2–3

Types. Holotype: female on slide, Thailand: Chumphon Province: Mueang District: Chang Puak cave, 10.446402°N, 99.035030°E, altitude 70 m., 6.iv.2016, S. Jantarit leg. (collection #THA_SJ_CPN08) . Paratypes: three females on slides and three in alcohol, same data as holotype. One paratype on slide and one in alcohol deposited in NJAU and others in PSU-NHM.

Description. Body length up to 2.82 mm. Body whitish in alcohol ( Fig. 2 ).

Antennae 3.70–4.48 times as long as cephalic diagonal. Antennal segment ratio as I: II: III: IV = 1: 1.55–1.78: 1.75–1.83: 3.00–3.11. Smooth spiny mic at base of antennae: three dorsal, two ventral on Ant. I, one internal, one external and two ventral on Ant. II. Long smooth straight chaetae absent on antennae. Distal Ant. II with 2–4 paddle-like chaetae ( Fig. 6 ). Two internal S-chaetae of Ant. III organ paddle-like ( Fig. 7 ). Subapical organ on Ant. IV not distinctly knobbed ( Fig. 8 ).

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. Clypeus with three prefrontal and eight facial chaetae; six facial chaetae minute; lateral chaetae often weakly ciliate ( Fig. 9 ). Dorsal cephalic chaetotaxy with two antennal (An), four median (M) and eight sutural (S) mac; Gr. II with 6(7) mac ( Fig. 10 ). Mandibles with 4+5 (4 left, 5 right) large apical teeth. Three smooth sublobal hairs on maxillary outer lobe ( Fig. 11 ). Lateral process of labial palp thicker than normal chaetae, with tip slightly beyond apex of labial papilla ( Fig. 12 ). Labial chaetae as mRel1l2, all smooth except R, ratio of R to m 0.44–0.55; chaetae X, X2 and X4 smooth and minute; chaeta X2 absent in one side of one specimen. Chaetae along cephalic groove 9–11; anterior three and the fifth smooth; small chaetae on posterior part often weakly ciliate ( Fig. 13 ).

Trochanteral organ with 12–22 smooth spine-like chaetae; 7–10 in arms and 5–12 between them ( Fig. 14 ). Partial inner differentiated tibiotarsal chaetae finely ciliate with ciliations not closely appressed to axis. Tibiotarsi distally with 10 chaetae in a whorl. Unguis with three inner teeth; two paired teeth unequal, outer one slightly larger. Unguiculus swollen with outer edge serrate. Tenent hairs usually pointed and II–III clavate in one specimen ( Fig. 15 ). Abd. IV 4.25–4.40 times as long as Abd. III along dorsal midline. Ventral tube anteriorly with 9–12 ciliate chaetae on each side and 2(3) of them much larger ( Fig. 16 ); posteriorly with four apical and about nine proximal chaetae ( Fig. 17 ), lateral two chaetae of apical ones ciliate in one specimen ( Fig. 18 ), proximal chaetae often weakly ciliate; each lateral flap with 7(10), 3–4 of them smooth ( Figs 16–17 ). Furcula without smooth chaetae. Distal part of manubrium ventrally with 11–15 ciliate chaetae on each side ( Fig. 19 ). Manubrial plaque with two pseudopores and 4–7 ciliate chaetae ( Fig. 20 ). Distal smooth part of dens 0.89–1.13 times as long as mucro. Mucro falcate with a long basal spine, nearly reaching the tip of the apical tooth ( Fig. 21 ).

Th. II with 4–6 medio-medial, three (m4, m 4i, m4p) medio-sublateral and 25–32 posterior mac; ms inner to sens. Th. III with 32–35 mac; p3ip2 present in one side of one specimen ( Fig. 22 , Table 2). Abd. I with 6–7 (a2–3, m2–4, m 2i, m4p) mac; a2 often as mic. Abd. II with three (m3, m3e, m3ep) central and one (m5) lateral mac. Abd.

III with two (a2, m3) central and three (am6, pm6, p6) lateral mac; Abd. IV with seven central (I, M, B4–6, A5–6) and 10–12 lateral mac; F1p and F3p sometimes absent ( Fig. 23 ). S-chaetae formula: 2+ms, 2/1+ms, 2, 2, ±20, 3; sens usually outer to ms but inner to ms on Abd. I in one specimen; lateral sens (acc.p6) of Abd. II–III as long as 0.6 times central as; as and ps on Abd. IV 1 /4 length of others. Sens acc.p5 anterior to m5 ( Figs 22–24 ).

GenBank number. KY704919 – KY704920 .

Ecology. A small population of the species was collected in the dark, deep zone of the cave, ca 30 meters from cave entrance in a wet and humid habitat near a pool, stalagmites, rock surfaces and floor.

Etymology. Name after the province “ Chumphon ” where this species was discovered.

Remarks. Coecobrya chumphonensis sp. nov. can be separated from other Coecobrya species by the combination of large size, long antennae, two antennal mac and 6(7) Gr. II mac on dorsal head, ciliate labial chaeta R, serrate outer edge on unguiculus, 4–6 medio-medial mac on Th. II, two central mac on Abd. III, 10–12 lateral mac on Abd. IV, and short, lateral sens acc.p6 on Abd. II–III. The position of lateral sens acc.p5 on Abd. V is also unique in the genus. The three new species described in this study and Coecobrya annulata Zhang, Bedos & Deharveng, 2016 are very similar in elongate antennae, labrum, minute postlabial chaetae X2 and X4, abundant chaetae on ventral chaetae, and relatively abundant mac on thorax, Abd. I and IV. They can be distinguished by the combination of characters listed in Table 3. It differs from other three species in two antennal, four median and 6(7) Gr. II mac on dorsal head, ciliate labial chaeta R, and 2+2 central mac on Abd. III.

TABLE]. K2P genetic đistances between 14 inđiviđuals. Abbreviations for population localities: CP, Chang Puak cave; PBS/STN, Phraya Bangsa cave; TD, Ton Din cave.

Species Individuals

Coecobrya chumphonensis sp. nov. CP̲sp5̲1

CP̲sp5̲2 0.0 0 0

Coecobrya polychaeta sp. nov. PBS̲sp1̲1 0.277 0.277

PBS̲sp1̲2 0.280 0.280 0.002

PBS̲sp1̲3 0.277 0.277 0.005 0.006

COLLH6547-16̲STN 0.262 0.262 0.049 0.051 0.049

COLLH6548-16̲STN 0.262 0.262 0.049 0.051 0.049 0.000 COLLH6549-16̲STN 0.262 0.262 0.049 0.051 0.049 0.000 0.000

Coecobrya cf. polychaeta sp. nov. TD̲cf̲sp1̲1 0.271 0.271 0.221 0.223 0.219 0.239 0.239 0.239 TD̲cf̲sp1̲2 0.271 0.271 0.221 0.223 0.219 0.239 0.239 0.239 0.000 TD̲cf̲sp1̲3 0.271 0.271 0.221 0.223 0.219 0.239 0.239 0.239 0.000 0.000 COLLH6520-16̲TD 0.273 0.273 0.223 0.225 0.221 0.239 0.239 0.239 0.000 0.000 0.000 COLLH6521-16̲TD 0.273 0.273 0.223 0.225 0.221 0.239 0.239 0.239 0.000 0.000 0.000 0.000 COLLH6522-16̲TD 0.273 0.273 0.223 0.225 0.221 0.239 0.239 0.239 0.000 0.000 0.000 0.000 0.000

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 6 – 15. Coecobrya chumphonensis sp. nov. 6, distal part of Ant. II of right antenna, dorsal view; 7, Ant. III organ of left antenna, dorsal view; 8, subapical organ of Ant. IV; 9, clypeal chaetae; 10, dorsal cephalic chaetotaxy; 11, maxillary outer lobe; 12, lateral process of labial palp; 13, labial and postlabial chaetae; 14, trochanteral organ; 15, hind claw.

FIGURES 16 – 21. Coecobrya chumphonensis sp. nov. 16, anterior face and lateral flap of ventral tube; 17 – 18, posterior face of ventral tube; 19, distal part of manubrium ventrally; 20, manubrial plaque; 21, mucro.

FIGURES 22 – 24. Tergal chaetotaxy in Coecobrya chumphonensis sp. nov. 22, Th. II – III; 23, Abd. I – IV; 24, Abd. V.