Coecobrya whitteni Nilsai & Jantarit, 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/84FBEE6D-88C3-459F-B8D7-1B8A741D7393 |
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taxon LSID |
lsid:zoobank.org:act:84FBEE6D-88C3-459F-B8D7-1B8A741D7393 |
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treatment provided by |
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scientific name |
Coecobrya whitteni Nilsai & Jantarit |
| status |
sp. nov. |
Coecobrya whitteni Nilsai & Jantarit sp. nov.
Figures 1A View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4
Type material.
Holotype: female on slide. Thailand, Khon Kaen province, Chum Phae district, Tham Nayn Noi (note: “tham” = “cave” in Thai), altitude 359 m a.m.s.l., 16.8292°N, 101.9848°E. 3.XII.2020; S. Jantarit, A. Nilsai, K. Sarakhamhaeng and K. Jantapaso leg. (sample # THA_SJ_KKN04), dark zone of a cave, by entomological aspirator. Paratypes: same data as holotype, 11 specimens (three female and eight subadults on slides). Additional material: same data as holotype, 3 specimens (in ethanol)
Holotype and 11 paratypes on slides deposited in NHM-PSU.
Description.
Habitus (Fig. 1A View Figure 1 ). Medium size Entomobryidae . Body length 1.8-2.3 mm (holotype 1.8 mm). No scales. Eyes absent. Color: whitish in alcohol, without pigmentation. Four antennal segments. Body slender not bent nor humped at the level of Th. II. Abd. IV 3.80-5.63 times as long as Abd. III along the dorsal midline.
Pseudopores (Figs 3F View Figure 3 , 4A-C View Figure 4 ). Pseudopores present as round flat disks, smaller than mac sockets, 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 the apical row of chaetae (2 psp on Ant. I, 2-3 psp on Ant. II, and 3 psp on Ant. III). On the 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 4A-C View Figure 4 ). 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. 3F View Figure 3 ).
Clypeus and mouthparts (Figs 2A-C View Figure 2 , 2H, I View Figure 2 , 3G View Figure 3 ). Clypeal area with three long, smooth prefrontal; six middle chaetae (2+2 small ciliated chaetae of unequal size posteriorly and 1+1 rather long, thin, smooth chaetae anteriorly); and 1+1 long smooth lateral chaetae (Fig. 3G View Figure 3 ). Prelabral and labral chaetae 4/5, 5, 4, all thin and smooth; the three median chaetae of the second row longer than two lateral ones (35-40 vs. 25 µm) (Fig. 2H View Figure 2 ). 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. 2H View Figure 2 ). Ventro-distal complex of labrum well differentiated, asymmetrical, with 1+1 distal combs of 14-19 minute teeth on the right side and 14-16 strong and larger teeth on the left side (Fig. 2A View Figure 2 ), 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 (55-60 vs. 35-38 µm) (Fig. 2B View Figure 2 ). Labial palp strongly modified for the genus, with 0, 5, 0, 4, 4 guards for papillae A-E, as described by Fjellberg (1999) for Entomobryidae or by Xu and Zhang (2015) and Jantarit et al. (2019) for Coecobrya . Lateral process of labial palp subcylindrical, as thick as normal chaetae, with tip beyond the apex of the labial papilla (Fig. 2C View Figure 2 ). Mandible apex blunt and strong, asymmetrical (left with four teeth, right with five teeth) (Fig. 2I View Figure 2 ); 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 as figured in Jantarit et al. (2019).
Antennae (Fig. 2D View Figure 2 ). Antennae very long, approximately 3.78-5.14 times as long as cephalic diagonal. Antennal segments ratio as I: II: III: IV. 1: 2.08-2.20: 2.17-2.21: 3.75-4.40 (N = 3). Antennal segments not subdivided nor annulated. Antennal chaetal types not analysed in detail. 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 (sensu Nilsai et al. 2017) on Ant II dorsally absent. Ant. III organ with typical five sens, sens one and four subequal, hyaline; sens five acuminate, and shorter; sens two and three swollen in paddle-like chaetae shape (Fig. 2D View Figure 2 ). Ant. IV without apical bulb. Subapical organite not distinctly knobbed, swollen, slightly enlarged apically, inserted dorsally.
Dorsal head chaetotaxy (Fig. 3D View Figure 3 ). Dorsal cephalic chaetotaxy with four antennal chaetae (An3a2 and An3 as mac, An1-2 as mes), four anterior mac (A0, A2-3 and A5), three median (M1, M2 and M4) and eight sutural (S) mac (S0, S1-7); Gr. II with four mac; A0 as mac; 5-7+5-7 scale-like structures (usually 6+6) (sensu Jantarit et al. 2019) present below sutural mac, probably inside the integument; a pair of short cephalic trichobothria, external and close to the middle of the head (Fig. 3D View Figure 3 ).
Ventral head chaetotaxy (Fig. 2E View Figure 2 ). 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: 0.13-0.14 (Fig. 2E View Figure 2 ). Postlabial chaetae X2, X and X4 smooth, acuminate and minute chaetae, of similar size, X3 normally absent but present as mic in one individual. On each side of the cephalic groove with 9 chaetae, of which, the proximal six always long and smooth, 7th and 9th as mics, 8th always long and ciliated, one specimen with three mics distally (Fig. 2E View Figure 2 ).
Tergite chaetotaxy (Figs 4A-D View Figure 4 ). Th. II with two (m1, m2) medio-medial, one (m4) medio-sublateral and 18-20 posterior mac; 1+1 ms and 2+2 sens antero-laterally (Fig. 4A View Figure 4 ).
Th. III with 23-26 mac. 2+2 sens laterally (Fig. 4A View Figure 4 ).
Abd. I with six central mac (m4i, m2-4, m2i, m4p), 1+1 ms and 1+1 sens laterally (Fig. 4B View Figure 4 ).
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. 4B View Figure 4 ).
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. 4B View Figure 4 ).
Abd. IV with four central mac (M, A5-6, B5) and six (D3, E2-4, E2p, F3) lateral mac, 2+2 tric and about 19 long S-like chaetae and one mic in the middle below psp, without modified chaetae (Fig. 4C View Figure 4 ).
Abd. V with at least 6 obvious mac and several mes to small mac, and 3+3 sens (Fig. 4D View Figure 4 ).
Abd. VI not analysed.
S-chaetae formula from Th. II to Abd. V: 2+ms, 2/1+ms, 2, 2, ≈ 20, 3; ps not seen, as sens on Abd. IV 1/3 as long as S-like chaetae (Figs 4A-D View Figure 4 ).
Legs (Figs 2G View Figure 2 , 3B View Figure 3 ). 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 18-21 smooth, straight, unequal spine-like chaetae (Fig. 3B View Figure 3 ). The distal whorl of tita III with 10 subequal ciliated mes, irregularly arranged, and usually claw I-II with dorso-apical clavate tenent hair (pointed in two specimens). A smooth, thin and long chaeta close to tenent hair (sensu Jantarit et al. 2019) absent. Claw III generally with dorso-apical clavate tenent hair (8 individuals with clavate tenant hair, 4 individuals with pointed tenant hair; holotype with pointed tenent hair Fig. 2G View Figure 2 ). Ventro-distal smooth chaeta of tita III thick, erected, pointed, rather short. Pretarsal mic minute (2.5-3.0 µm). Claw slender and elongated. Unguis of all claw with one small inner teeth at 53 % and a pair of unequal basal teeth at about 44-49 % of inner edge from basis. Unguiculus approximately 2/3 as long as inner edge of claw, rather swollen baso-externally, pointed apically, devoid of inner tooth, with at least five minute outer teeth, often inconspicuous, at 3/4 of its length (Fig. 2G View Figure 2 ).
Ventral tube (Figs 3C, E View Figure 3 ). Ventral tube two to three times longer than wide. Lateral flaps with 6-7+6-7 smooth chaetae except for one specimen with one ciliated chaeta present in both sides (Fig. 3C View Figure 3 ). Anterior face with 6-8+6-8 chaetae, 2(3) of them larger than others, all ciliated, arranged roughly asymmetrically (Fig. 3E View Figure 3 ); posterior face with at least 12 chaetae, four apical chaetae longer and larger than others and about 8-13 proximal chaetae; two straight smooth chaetae and 6-11 either small finely ciliated or mics arranged asymmetrically (Fig. 3C View Figure 3 ).
Furcal complex (Figs 2F View Figure 2 , 3A, F View Figure 3 ). 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 1.6 times longer than manubrium. Furcula without smooth chaetae. Manubrium with a dense cover of ciliated chaetae both dorsally and ventrally. Manubrial plaque with 2+2 psp and three to six ciliated chaetae (usually 5+5) (Fig. 3F View Figure 3 ). Distal part of manubrium ventrally with 13+13 ciliate chaetae (Fig. 3A View Figure 3 ). Dens without spines, annulated and covered with ciliated chaetae on both sides. Distal smooth part of dens slightly longer than mucro. Mucro strong and falcate, basal spine long, reaching the tip of the mucronal tooth (Fig. 2F View Figure 2 ).
Genital plate. Female genital plate with 2+2 genital mic, male genital plate not clearly seen.
Ecology.
Coecobrya whitteni sp. nov. was found in the dark zone of a cave on the surface of the muddy ground, near the bank of a stream. It was also found in the upper levels on stalagmites, clay, gravel and rock surfaces. This species was found mainly in eutrophic habitats where piles of guano were well-presented. There was a big colony of the intermediate roundleaf bat ( Hipposideros larvatus ) inside the cave. The air temperature of the habitat where this species was collected was 22.9-24.0 °C and the relative humidity was 85%. In the same cave, and in the same chamber, at least six different stygobitic species were also observed in the small puddles: Aequigidiella aquilifera , Dugesia deharvengi , Heterochaetella glandularis , Siamoporus deharvengi , Stenasellus rigali and Theosbaena cambodjiana . The co-occurrence of these six species was first observed in 1987 ( Association Pyrénéenne de Spéléologie 1988; Deharveng and Bedos 2000, 2012) and from our observations they are all still present in rather large numbers of individuals. We also found a millipede ( Plusioglyphiulus saksit ) and a spider ( Speocera deharvengi ) in the same habitat where this new species was found. Most of these observed species only known as endemics to this cave. The discovery of this new species in Tham Nayn Noi emphasizes the importance of this cave in harboring the endemic subterranean fauna of the area.
Etymology.
Coecobrya whitteni sp. nov. is named in honor of the late Tony Whitten in appreciation of his enormous contributions to the discovery and conservation of karst and cave invertebrates across Asia.
Remarks.
Among the described troglomorphic Coecobrya species in Thailand, Coecobrya whitteni sp. nov. is near to C. cavicta Nilsai & Zhang, 2017 from Satun province, southern Thailand in the body length, dorsal head chaetotaxy, labial chaetae, number of sublobal hairs on maxillary outer lobe, number of mac on Abd.III and number of chaetae on ventrodistal part of manubrium. However, it differs from C. cavicta by the combination of various characters i.e. longer length of antennae, number of mac of dorsal tergits on Th. II (21-23 vs. 36-37), Th. III (23-26 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 organe (18-21 vs. 15-16) (see Table 1 View Table 1 ). In fact, Coecobrya whitteni sp. nov. is most similar to C. troglobia sp. nov. which is described in this work since the caves where these two species are found are only 3.4 km apart in a straight line, separated by limestone mountains. The altitudes of the two caves differs by about 200 m. The two species are similar in body size, antennal length, number of sublobal hair on the maxillary outer lobe, number of chaetae on Gr. II, labial chaetae, number of mac on Abd. I-IV, number of inner teeth of the claw, tenent hair, similar number in ventral tube chaetae both anterior and posterior side as well as a lateral flap, number of chaetae on trochanteral organ (Table 1 View Table 1 ). However, Coecobrya whitteni sp. nov. differs from C. troglobia sp. nov. by the number of An dorsal mac on the head (4 vs. 5) and number of chaetae on Th. II (medio-medial mac = 2 vs. 3, medio-sublateral mac = 1 vs. 4) (Table 1 View Table 1 ). Coecobrya whitteni sp. nov. has in fact already been mentioned by Deharveng and Bedos (2000) as an undescribed cf. Coecobrya species (Fig. 31.8A page 625) from oligotrophic habitats. (Note that in this reference the cave is misnamed as Tham Kubio).
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