Coecobrya troglobia Jantarit & Nilsai, 2021
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publication ID |
https://dx.doi.org/10.3897/subtbiol.41.76926 |
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publication LSID |
lsid:zoobank.org:pub:73326F5C-C4BE-431D-BE6D-601A69BD7FFA |
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persistent identifier |
https://treatment.plazi.org/id/392BEEC9-7496-49B0-BF2E-3A3822F60A0B |
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taxon LSID |
lsid:zoobank.org:act:392BEEC9-7496-49B0-BF2E-3A3822F60A0B |
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treatment provided by |
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scientific name |
Coecobrya troglobia Jantarit & Nilsai |
| status |
sp. nov. |
Coecobrya troglobia Jantarit & Nilsai sp. nov.
Figures 1B View Figure 1 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7
Type material.
Holotype: female on slide. Thailand, Khon Kaen province, Chum Phae district, Tham Phaya Nakharat, altitude 562 m a.m.s.l., 16°48'50.5"N, 101°57'23.9"E. 3.XII.2020; S. Jantarit, A. Nilsai, K. Sarakhamhaeng and K. Jantapaso leg. (sample # THA_SJ_KKN03), dark zone of a cave, by entomological aspirator. Paratypes: same data as holotype, 7 specimens (3 females and 4 subadults on slides). Additional material: same data as holotype, 6 specimens (in ethanol).
Holotype and seven paratypes on slides deposited in NHM-PSU.
Description.
Habitus (Fig. 1B View Figure 1 ). Medium size Entomobryidae . Body length 2.0-2.4 mm (holotype 2.4 mm). No scales. Eyes absent. Color: whitish in alcohol, without pigmentation. Four antennal segments (sometimes Ant. II and III fused together). Body slender not bent nor humped at the level of Th. II., elongated antennae, legs and furca. Th. II slightly larger than Th. III; Abd. IV about 3.5 times as long as Abd. III along the dorsal midline.
Pseudopores (Figs 6D View Figure 6 , 7A-C View Figure 7 ). Pseudopores present as round flat disks, smaller than mac sockets (Figs 7A-C View Figure 7 ), except for the coxae and manubrium where psp are as large as mac sockets, present on various parts of the body: antennae, head, tergites, coxae and manubrium. On antennae, psp located ventro-apically between the tip of antennal segments and the chaetae of the apical row, or just below apical row of chaetae (2 psp on Ant. I, 2-3 psp on Ant. II, and 3 psp on Ant. III). On head, 1-2 psp located externally on each peri-antennal area. On tergites, 1+1 psp close to the axis from Th. II to Abd. IV (Figs 7A-C View Figure 7 ). On coxae, 1-2 psp on coxae I, 2-3 psp on coxae II and 1-2 psp on coxae III, located close to longitudinal rows of chaetae. On manubrium, 2+2 dorso-apical ones (Fig. 6D View Figure 6 ).
Clypeus and mouthparts (Figs 5A, B, D, G, H View Figure 5 , 6H View Figure 6 ). Clypeal area with nine chaetae arranged in three rows, three long smooth prefrontal, 2+2 small ciliated chaetae sometimes asymmetric arrangement, and 1+1 long smooth facial chaetae, the lateral long smooth chaetae not seen (Fig. 5H View Figure 5 ). Prelabral and labral chaetae 4/5, 5, 4, all thin and smooth; three median chaetae of the second rows longer and slightly larger than those of the distal and proximal rows and longer than lateral ones (35-40 vs. 25-30 µm) (Fig. 5A View Figure 5 ). Distal border of the apical non-granulated area of the labrum with a relatively narrow median U- or V-form intrusion into the granulated area dorsally; apical edge without spines (Fig. 5A View Figure 5 ). Ventro-distal complex of labrum well differentiated, asymmetrical, with 1+1 distal combs of 14-16 minute on the right side and 14-16 strong and larger teeth on the left side (Fig. 5B View Figure 5 ), and an axial pair of long sinuous tubules. Maxillary outer lobe with one basal chaeta, one apical chaeta (basal chaeta thicker than apical one) and three smooth sublobal hairs (60-65 vs. 35-38 µm) (Fig. 5D View Figure 5 ). Labial palp strongly modified for the genus, with 0, 5, 0, 4, 4 guards for papillae A-E. Lateral process of labial palp subcylindrical, as thick as normal chaetae with tip beyond the apex of the labial papilla (Fig. 5G View Figure 5 ). Mandible apex strong, asymmetrical (left with four teeth, right with five teeth) (Fig. 6H View Figure 6 ); molar plate with three strong pointed basal teeth, and 3-(5) smaller inner distal teeth, identical in both mandibles. Maxilla capitulum with a three-toothed claw and several stout ciliated lamellae; lamella 2 large and broad, lamella 3 well developed; several other lamellae present.
Antennae (Figs 5C, E View Figure 5 ). Antennae very long, approximately 4.0-6.8 times as long as cephalic diagonal. Antennal segments ratio as I: II: III: IV = 1: 1.1-2.7: 0.7-2.4: 2.1-4.6 (N = 5). Antennal segments not subdivided nor annulated. Antennal chaetal types not analysed in detail. Smooth spiny mic at base of antennae: 3 dorsal, 3 ventral on Ant. I, 1 internal, 1 external and 1 ventral on Ant. II, 1 smooth ventral on Ant. I, smooth straight long chaetae on antennae present. Ant. I ventrally with many smooth spiny mic of various sizes in its basal part, many subcylindrical, hyaline sens in its middle to apical part, and many long smooth straight chaetae. The paddle-like chaetae on Ant II absent. Ant. III organ with five sens; sens one and four subequal, hyaline; sens five acuminate, dark and shorter; sens two and three swollen (Fig. 5C View Figure 5 ). Ant. IV very long, not subdivided, without apical bulb. Subapical organite not distinctly knobbed, swollen, slightly enlarged apically, inserted dorsally (Fig. 5E View Figure 5 ).
Dorsal head chaetotaxy (Fig. 6I View Figure 6 ). Dorsal cephalic chaetotaxy with five antennal chaetae (An1-3, An3a, An3a2, An1 as mes), four anterior mac (A0, A2-3 and A5) three median (M1-2, M4) and eight sutural mac (S0, S1-7); Gr. II with four mac; A0 as mac; 6+6 scale-like structures present below sutural mac, probably inside the integument; a pair of short cephalic trichobothria, external and close to the middle of the head (Fig. 6I View Figure 6 ).
Ventral head chaetotaxy (Fig. 5F View Figure 5 ). Chaetae of labial basis all smooth (mrel1l2), chaetae m, e and l1 subequal, r thin and shortest, and l2 longest, The r/m length ratio: 0.11-0.16 (Fig. 5F View Figure 5 ). Postlabial chaetae X2, X and X4 smooth and minute chaetae, X1 and X3 absent. On each side of cephalic groove with 9 chaetae, of which the anterior six always long and smooth, 7thand 9th as mics, 8th always long and ciliated, one specimen with three mics distally in one side (Fig. 5F View Figure 5 ).
Tergite chaetotaxy (Figs 7A-D View Figure 7 ). Th. II with three (m1, m2, m2i2) medio-medial, two (m4, m4p) medio-sublateral and 15-18 posterior mac; 1+1 ms and 2+2 sens antero-laterally (Fig. 7A View Figure 7 ).
Th. III with 24-27 mac, a4i and a6i as mac, 2+2 sens laterally (Fig. 7A View Figure 7 ).
Abd. I with six (m2-4, m2i, m4p, m4i) mac, 1+1 ms and 1+1 sens laterally (Fig. 7B View Figure 7 ).
Abd. II with two (m3, m3e) central and one (m5) lateral mac. 2+2 tric without modified chaetae, 1+1 sens laterally and 1+1 mic near internal tric (Fig. 7B View Figure 7 ).
Abd. III with one (m3) central, and three (am6, pm6, p6) lateral mac. 3+3 tric without modified chaetae, 1+1 sens laterally, 1+1 mic near m3, ms not seen (Fig. 7B View Figure 7 ).
Abd. IV with five central mac (I, A5-6, B4-5) and six (D3, E1, E2p, E3-4, F3) lateral mac, 2+2 tric and about 18 long S-like chaetae anteriorly, without modified chaetae (Fig. 7C View Figure 7 ).
Abd. V with 15-18 mac and several mes to small mac, and 3+3 sens (Fig. 7D View Figure 7 ). Abd. VI not analysed. S-chaetae formula from Th. II to Abd. V: 2+ms, 2/1+ms, 2, 2, ≈15-18, 3; ps not seen, as sens on Abd. IV 1/3 as long as S-like chaetae (Figs 7A-D View Figure 7 ).
Legs (Figs 6E, G View Figure 6 ). Leg long; tita of leg III slightly longer than tita of legs I and II. Legs devoid of scales, covered with ordinary ciliated chaetae of various lengths, mic not seen. Trochanteral organ with 19-23 smooth, straight, unequal spine-like chaetae (Fig. 6E View Figure 6 ). The distal whorl of tita with 9-10 subequal ciliated mes, irregularly arranged, and usually dorso-apical clavate tenent hair present (two specimens claw III with pointed tenent hair). A smooth, thin and long chaeta close to the absent tenent hair. Ventro-distal smooth chaeta of tita III thick, erected, pointed, rather short. Claw rather slender and elongated. Unguis of all claws with two inner teeth, one-minute tooth at about 90 % from base of the claw, and a strong inner tooth at 40-46 %, and a pair of subequal basal teeth at about 30-34 % of inner edge from basis. Unguiculus approximately 2/3 as long as inner edge of the claw, rather swollen baso-externally, pointed apically, with one inner tooth and at least four minute outer teeth, often inconspicuous near the tip of its length (Fig. 6G View Figure 6 ).
Ventral tube (Figs 5I View Figure 5 , 6A-C View Figure 6 ). Ventral tube three to four times longer than wide. Lateral flaps usually with 7-9+7-9 smooth chaetae, sometimes 1-2 ciliated present. In the holotype, 10 smooth and one ciliated chaeta present on one side (Fig. 5I View Figure 5 ). Anterior face with 7-9+7-9 ciliated chaetae, three of them apically larger than others (Fig. 6B View Figure 6 ); posterior face with 4 long, smooth chaetae apically, the middle chaetae with 4-6 long, smooth chaetae mixed with 5-6 mic arranged roughly asymmetrically, and 2-3 proximal chaetae, ciliated in the holotype (Fig. 6C View Figure 6 ) but smooth in 2 specimens (Fig. 6A View Figure 6 ).
Furcal complex (Figs 6D, F View Figure 6 ). Tenaculum with four large teeth of decreasing size from the basal to the distal one of each ramus, on a prominent, irregular body, with a postero-basal strong serrated chaeta bent distally. Mucrodens 1.15-1.42 times longer than manubrium. Furcula without smooth chaetae. Manubrium densely cover of ciliated chaetae both dorsally and ventrally. Manubrial plaque with 2+2 psp and five ciliated chaetae (Fig. 6D View Figure 6 ). Distal part of the ventral manubrium not clearly seen in all specimens. Dens without spines, annulated and covered with ciliated chaetae on both sides. Distal smooth part of dens as long as the mucro. Mucro strong and falcate, basal spine long, nearly reaching the tip of the mucronal tooth (Fig. 6F View Figure 6 ).
Genital plate. Female genital plate with 2+2 genital mic.
Ecology.
Coecobrya troglobia sp. nov. is restricted to the dark zone of the cave, where it was found in two chambers in an oligotrophic environment. Most individuals were found on the floor, on stalagmites and on the rock walls. The temperature in the dark zone was 21.4-23 °C and the relative humidity was about 75 %.
Etymology.
The name of the new species is derived from the Greek stem "trogle ( τρώγλη)” which means “hole”, referring to the habitat of this new species which is restricted to the subterranean environment.
Remarks.
Coecobrya troglobia sp. nov. is also near to C. cavicta Nilsai & Zhang, 2017 from Satun province, southern Thailand in the number of mac of M series and Gr. II of dorsal head chaetotaxy, labial chaetae, number of sublobal hairs on maxillary outer lobe, number of mac on medio-medial area of Th.II, number of mac on Abd. III. However, Coecobrya troglobia sp. nov. is diffent from C. cavicta by having bigger body size, longer length of antennae, number of chaetae along cephalic groove, number of mac of dorsal tergits on Th. II (20-23 vs. 36-37), Th. III (24-27 vs. 35), Abd. II (2 vs. 3) and Abd. IV (11 vs. 18-20), number of inner teeth of claw (3 vs. 2) and number of smooth chaetae of trochanteral organ (19-23 vs. 15-16) (see Table 1 View Table 1 ). Coecobrya troglobia sp. nov. is close to C. whitteni sp. nov. from Tham Nayn Noi in Chum Phae district, Khon Kaen province, but they clearly differ from each other in a few morphological characters, see the detailed diagnosis in the remarks under C. whitteni sp. nov. and Table 1 View Table 1 .
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