Thalassaphorura bapen, Sun, Xin, Chen, Jian-Xiu & Deharveng, Louis, 2010

Sun, Xin, Chen, Jian-Xiu & Deharveng, Louis, 2010, Six new species of Thalassaphorura (Collembola, Onychiuridae) from southern China, with a key to world species of the genus, Zootaxa 2627, pp. 20-38 : 25-26

Thalassaphorura bapen sp. nov.

Figs 1 , 14 , 20 , 26 & 32 , Tab. 1 .

Type material. Holotype male, one paratype male and one paratype juvenile. China: Guangxi Province: Fushui: Bapen Nature Reserve: 4.iii.2005, soil, berlese, L. Deharveng & A. Bedos leg. (CHIgx05–028); ibid: 5 paratypes on slide, about 100 paratypes in alcohol, 4.iii.2005, litter, berlese, L. Deharveng & A. Bedos leg. (CHIgx05–011, 025). Holotype and 3 paratypes on slide and about 50 paratypes in alcohol in NJU; 4 paratypes on slide and about 50 paratypes in alcohol in MNHN.

Description. Body length: females 1.25–1.4 mm, males 1.0– 1.25 mm. Body shape: cylindrical, Abd. III– IV more or less broadened. Body color: white in alcohol.

Pseudocelli formula as 32/122/33343 dorsally, 11/000/01010 ventrally, subcoxa 1 of legs I, II and III with 2, 2 and 2 pso respectively ( Fig. 14 ). Parapseudocelli: 1+1 on sternum of Abd. I, near base of ventral tube ( Fig. 32 ). Pseudopore formula as 00/011/11110 dorsally, 00/111/000x0 ventrally.

S-chaeta formula as 11/011/222120 dorsally ( Fig. 14 ). Sp present on head. S-microchaeta tiny and blunt, present on Th. II and III dorsally.

Head. Antennae short and distinctly segmented, 0.9 times as long as head. Length ratio of antennal segments I: II: III: IV = 1: 1.5–1.7: 1.5–1.7: 2.4. Ant. I with 8 chaetae. Ant. II with 13 chaetae. Ant. III sensory organ composed of 5 papillae, 5 guard chaetae, 2 small rods and 2 smooth subequal clubs; lateral ms just behind sensory organ. Ant. IV subapical organite with apex globular; basolateral ms at about 2/5 length from base. Antennal base without distinct granulation. PAO composed of 22–24 simple vesicles arranged in 2 rows along axis of organ. Dorsal cephalic chaeta d0 present. 3+3 p-chaetae between posterior a-pso on head, p1 anterior to others. Mandible with strong molar plate and 4 apical teeth. Maxilla bearing 3 teeth and 6 lamellae. Maxillary palp simple with 1 basal chaeta and 2 sublobal hairs. Labral chaetae 4/142. Labial papillae of AC type, papillae A–E respectively with 1, 4, 0, 3 and 2 guard chaetae. Labium with 6 proximal, 4 (E, F, G and f) basomedian and 6 (a, b, c, d, e, e’) basolateral chaetae. Postlabial chaetae 4+4 along ventral groove.

bapen grandis pomorskii reducta tiani tibiotarsalis * Two chaetae a 1 in replacement of a0.

Body chaetotaxy. Ordinary chaetae differentiated in meso- and macrochaetae, ratio Sp: m1: p1 on Abd. V = 1: 0.5: 1.5 ( Fig. 20 ). Th. II–Abd. III respectively with 3+3 dorsal chaetae along axial line, without dorsal median chaetae. Abd. IV tergite with axial chaeta m0, Abd. V without axial chaetae, Abd. VI with chaeta a0 and m0 ( Fig. 20 ). Th. I, II and III with 1+1, 1+1 and 1+1 chaetae respectively between legs. Subcoxa 1 of legs I, II and III with 3, 4, 4 chaetae, subcoxa 2 with 1, 4 and 4 chaetae respectively.

Appendages. Tibiotarsi I, II and III with 18 (9, 8, 1), 18 (9, 8, 1) and 18 (9, 8, 1) chaetae. Unguis without teeth. Unguiculus slender and pointed, 0.4 times as long as inner edge of unguis, with narrow inner basal lamella ( Fig. 26 ). Ventral tube with 6+6 distal chaetae and 1+1 basal chaetae, without anterior chaetae ( Fig. 32 ). Furca reduced to a finely granulated area, with 4 small chaetae in two rows posterior to furcal rudiment.

Genital plate with 19 chaetae in females, 32–40 in males. Anal valves with numerous acuminate chaetae; each lateral valve with chaetae a0 and 2a1; upper valve with chaetae a0, 2a1, 2b1, c0, 2c1, 2c2. Anal spines set on distinct papillae, 0.4 times as long as inner edge of hind unguis ( Fig. 20 ).

Ecology. In forest litter and soil.

Etymology. Named for the place where we found them.

Remarks. Bisexual species. The new species shares with reducta sp. nov. the same dorsal pso formula, presence of basal lamella on unguiculus, number of chaetae on ventral tube and presence of a0 and p0 on Abd. VI. But they can be easily separated by the following characters: length of AS ( AS equals 0.4 unguis in bapen sp. nov. versus AS equals 0.2–0.25 unguis in reducta sp. nov.), number of vesicles on PAO (22–24 in bapen sp. nov. versus 15–19 in reducta sp. nov.), pseudocellar formula ventrally (11/000/01010 in bapen sp. nov. versus 11/000/01000 in reducta sp. nov.), number of pso on subcoxa 1 of legs I, II and III (2, 2 and 2 in bapen sp. nov. versus 1, 1 and 1 in reducta sp. nov.), anterior chaetae of ventral tube (absent in bapen sp. nov. versus 1+ 1 in reducta sp. nov.), dorsal axial chaeta on Abd. V (absent in bapen sp. nov. versus present in reducta sp. nov.) and number of chaetae on Th. I (6+ 6 in bapen sp. nov. versus 4–5+ 4–5 in reducta sp. nov.) ( Tab. 1 ).

Figures

FIGURE 1. Sampling localities in Guangxi, with list of species.

FIGURES 14 – 19. Sensilla and pso on the dorsal side. 14, Thalassaphorura bapen sp. nov.; 15, Thalassaphorura grandis sp. nov.; 16, Thalassaphorura pomorskii n. sp.; 17, Thalassaphorura reducta n. sp.; 18, Thalassaphorura tiani n. sp.; 19, Thalassaphorura tibiotarsalis n. sp. Scales: 0.1 mm.

FIGURES 20 – 25. Tergites of Abd. V – VI. 20, Thalassaphorura bapen sp. nov.; 21, Thalassaphorura grandis sp. nov.; 22, Thalassaphorura pomorskii sp. nov.; 23, Thalassaphorura reducta sp. nov.; 24, Thalassaphorura tiani sp. nov.; 25, Thalassaphorura tibiotarsalis sp. nov. Scales: 0.01 mm.

FIGURES 26 – 31. Tibiotarsus and claw. (A: leg I, B – F: leg III). 26, Thalassaphorura bapen sp. nov.; 27, Thalassaphorura grandis sp. nov.; 28, Thalassaphorura pomorskii sp. nov.; 29, Thalassaphorura reducta sp. nov.; 30, Thalassaphorura tiani sp. nov.; 31, Thalassaphorura tibiotarsalis sp. nov. Scales: 0.01 mm.

FIGURES 32 – 37. Ventral tube chaetotaxy. 32, Thalassaphorura bapen sp. nov.; 33, Thalassaphorura grandis sp. nov.; 34, Thalassaphorura pomorskii sp. nov.; 35, Thalassaphorura reducta sp. nov.; 36, Thalassaphorura tiani sp. nov.; 37, Thalassaphorura tibiotarsalis sp. nov. Scales: 0.01 mm.

Tables

TABLE 1. Comparison of the six new species of Thalassaphorura. Brackets in axial chaetae: asymmetrical position of chaetae.

Number of vesicles in 22–24 PAO	21–26	12–14	15–19	24–26	17–18
Type of labial papillae AC	AC	AC	AC	AC	ABC
Dorsal pso formula 32/122/33343	32/133/33343	32/233/33343	32/122/33343	32/233/33343	32/233/33343
Ventral pso formula 11/000/01010	11/000/01110	11/00/01110	11/000/01000	11/000/01120	11/000/01120
Number of pso on 2/2/2 subcoxa 1 of leg I–III	2/2/2	2/2/2	1/1/1	2/2/2	2/2/2
S-chaetae formula 11/011/222120	indistinct	11/011/222120	11/011/222120	11/011/222120	11/011/222120
Ventral tube chaetotaxy 0+0/6+6/1+1	0+0/6+6/2+2	1+1/6+6/1+1	1+1/6+6/1+1	1+1/6+6/2+2	0+0/6+6(7)/2+2
Number of chaetae on 3/4/4 subcoxa 1 of leg I–III	4/4/4	2/4/4	female:2/4/4; male:2/4(3)/4(3)	4/4/4	3/3/3
Number of chaetae in 9 distal whorl of tibiotarsi	9	9	9	9	7
Ratio of unguiculus/ 0.4 unguis	0.4–0.5	0.5–0.6	female: 0.3–0.4; male: 0.2–0.3	0.5	0.5
Axial chaetae IV/V/VI m0/–/a0&m0 Ratio of AS/unguis 0.4	m0/–/m0 * 0.75	m0/(a0m0)/a0 0.2	m0/a0/a0&m0 0.2–0.25	m0/a0/a0&m0 1	m0/–/a0 0.7
Length (mm) 1.0–1.4	1.4–1.6	0.8–1.1	0.65–0.95	0.80–1.1	0.6–0.7