Thalassaphorura pomorskii Sun, Chen & Deharveng, 2010, sp. nov.

Thalassaphorura pomorskii sp. nov.

Figs 1–13, 16, 22, 28 & 34, Tab. 1.

Type material. Holotype female and 4 paratypes female on slide, 35 paratypes in alcohol. China: Guangxi: Huanjiang: Min Li forest (E 107.96647°, N 25.09935°): 14.iii.2005, litter, berlese, L. Deharveng & A. Bedos leg. (CHIgx05–109) – ibid: 6 paratypes on slide, 51 paratypes in alcohol, litter, berlese, L. Deharveng & A. Bedos leg. (CHIgx05–100, –104, –108) – ibid: near Hong Dong (alt. 680m, E 107.9747°, N 25.11825°): 3 paratypes on slide, 15 paratypes in alcohol 15 paratypes, 13.ii.2009, litter, sifting and berlese, L. Deharveng leg. (CHIgx09–004). Holotype and 6 paratypes on slide and many in alcohol in NJU; 7 paratypes on slide and many in alcohol in MNHN.

Other material. Yachang: forest near Yan Wu Dong (Alt. 1359m, E 106.43133°, N 24.82364°), 31.v.2007: 5 on slide, 30 in alcohol, secondary forest, Quercus and Castanopsis, litter, berlese after sifting, L. Deharveng & A. Bedos leg. (CHIgx 07–31–03).

Description. Body length: females 0.8–1.1 mm. Body shape: cylindrical, Abd. III–IV more or less broadened. Body color: white in alcohol.

Pseudocelli formula as 32/233/33343 dorsally, 11/000/01110 ventrally, subcoxa 1 of legs I, II and III with 2, 2 and 2 pso respectively (Fig. 16). Parapseudocelli: 1+1 on sternum of Abd. I, near base of ventral tube (Fig. 34). Pseudopore formula as 00/011/11110 dorsally, 00/111/000x0 ventrally (Figs 2, 9 & 10).

S-chaeta formula as 11/011/222120 dorsally (Fig. 16). Sp present on head. S-microchaeta tiny and blunt, present on Th. II and III dorsally.

Head. Antennae short and distinctly segmented, 0.9–1.0 times as long as head. Length ratio of antennal segments I: II: III: IV = 1.0: 1.5–1.7: 1.5–1.7: 2.5. Ant. I with 9 chaetae. Ant. II with 12 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 12–14 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, not examined in detail. Maxillary palp simple with 1 basal chaeta and 2 sublobal hairs. Labral chaetae 4/1,4,2. 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 (Figs 2–8).

Body chaetotaxy. Ordinary chaetae differentiated in meso- and macro-chaetae, ratio Sp: m1: p1 on Abd. V = 1: 0.7: 1.8 (Fig. 22). Th. I with 5+5 dorsal chaetae. Th. II–Abd. III respectively with 3+3 dorsal chaetae along axial line, without axial chaeta. Abd. IV tergite with axial chaeta m0, Abd. V with a0, Abd. VI with a0 (Figs 2 & 22). 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 2, 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, 0.4–0.5 times as long as inner edge of unguis, with narrow inner basal lamella (Fig. 28). Ventral tube with 1+1 anterior chaetae, 6+6 distal chaetae and 2+2 basal chaetae (Fig. 34). Furca reduced to a finely granulated area, with 4 small chaetae in two rows posterior to furcal rudiment (Fig. 10).

Genital plate with 14–15 chaetae in females (Fig. 11). Anal valves with numerous acuminate chaetae; each lateral valve with chaetae a0 and 2a1; upper valve with chaetae a0, 2a1, 2b1, c0, 2c1, 2c2 (Fig. 12). Anal spines very small, 0.2 times as long as inner edge of hind unguis (Figs 2 & 22).

Ecology. In forest litter.

Etymology. Named in honor of Romuald Jacek Pomorski for his outstanding contributions to the knowledge of Onychiuridae.

Remarks. Probably parthenogenetic (no male versus 19 females among examined specimens). Thalassaphorura pomorskii sp. nov. has the same dorsal and ventral pso formula as T. duplopunctata, but differs in a lower number of chaetae on Th. I tergite and smaller size. The original description of T. duplopunctata is very succinct; Fjellberg (1998) added a few additional information, and the species needs a full redescription. The species is found in rather large populations in the forest litter of the Mulun karst.