New Chinese species of the genus Thalassaphorura Bagnall, 1949 (Collembola: Onychiuridae) Author Sun, Xin Author Li, Yu text Zootaxa 2015 3931 2 261 271 journal article 10.11646/zootaxa.3931.2.5 32c5ef1c-39c6-400a-9253-a7a48288ed82 1175-5326 239478 A61B92F6-8D88-4C29-BCCB-783E73D0A8DC Thalassaphorura guangdongensis sp. nov. Figs 1–11 Type material. Holotype female, China , Guangdong Province, He Mountain, 22 October 2012 , soil of secondary eucalypt forest, Berlese extraction, Xu Guoliang leg. Paratypes 10 females and 2 males , same data as holotype . Description. Body white in alcohol. Length of body 1.30–1.40 mm in females, 0.70–0.80 mm in males (both are juvenile); holotype 1.30 mm. Shape of body: cylindrical with anal spines on papillae. Anal spines 0.6 times as long as inner edge of hind unguis. Pso formulae 32/122/33343 dorsally and 11/000/01010 ventrally ( Figs 1, 5 ). Subcoxae 1 of legs I–III with 2 pso each. Psx formulae 00/000/100000 ventrally ( Figs 1, 5 ). Subcoxae 1 of legs I–III without psx. Psp formulae 00/ 011/ 111100 dorsally and 00/111/0001m0 0 ventrally ( Figs 1, 5 ). Head. Antennae as long as head. Length ratio of Ant. I: II: III: IV as about 1: 1.5: 1.5: 2.3 ( Fig. 3 ). Subapical organite on Ant. IV with globular apex; basolateral ms at about 2/5 length from base, above the second proximal row of chaetae ( Fig. 3 ). Ant. III sensory organ consists of 5 papillae, 5 guard chaetae, 2 small rods, and 2 smooth sensory clubs; lateral ms just behind sensory organ ( Figs 2, 3 ). Ant. II with 13 chaetae. Ant. I with 9 chaetae. Antennal base well marked. PAO with 20–22 simple vesicles arranged in two rows along axis of organ ( Figs 6, 7 ). Dorsal cephalic chaeta d0 present ( Figs 1 , 6 ). On head 4+4 medial p-chaetae present between posterior pso, p1 anterior to others ( Figs 1 , 6 ). Mandible with strong molar plate and 4 apical teeth. Maxilla bearing 3 teeth and 6 lamellae. Maxillary palp simple with 1 basal chaeta, with 2 sublobal hairs. Labral chaetae 4/142. Labium with 6 proximal, 4 basomedian (E, F, G, and f) and 6 basolateral (a, b, c, d, e, e’) chaetae; labial type AC, papillae A–E with 1, 4, 0, 3 and 2 guard chaetae respectively ( Fig. 8 ). Postlabial chaetae 4+4 along ventral groove. Body chaetotaxy. S-chaetae not well differentiated from ordinary chaetae. Tiny and blunt ms present on both Th. II and III ( Fig. 1 ). Th. I tergum with 6+6 chaetae ( Fig. 1 ). Th. II–III terga with 3+3 chaetae and Abd. I–III terga with 2+2 chaetae along axial line respectively, without axial chaetae ( Fig. 1 ). Abd. IV tergum with one axial chaeta m0, Abd. V tergum with asymmetrical chaetae, Abd. VI tergum with one axial chaeta m0 ( Fig. 1 ). Th. I–III sterna with 1+1, 1+1, 1+1 chaetae respectively. Appendages. Subcoxae 1 of legs I–III with 4, 4 and 4 chaetae, subcoxae 2 with 1, 4 and 4 chaetae respectively. All tibiotarsi with 18 (1, 8, 9) chaetae ( Fig. 4 ). Unguis without teeth. Unguiculus 0.7 times as long as inner edge of unguis, without inner basal lamella ( Fig. 1 ). Ventral tube with 6+6 distal and 2+2 basal chaetae, anterior chaetae absent. Furca reduced to finely granulated area, with 4 small dental chaetae arranged in two rows posteriorly and one manubrial row of chaetae ( Figs 5 , 11 ). Genital plate with 15–23 chaetae in females, 18 in males (juvenile). Male ventral organ not observed. Anal valves with numerous acuminate chaetae; each lateral valve with chaetae a0, 2a1 and 2a2; upper valve with chaetae a0, 2b1, 2b2, c0, 2c1 and 2c2 ( Fig. 9 ). Ecology. In the soil of secondary eucalypt forest. Derivatio nominis . Named after the type locality. FIGURE 1–5. Thalassaphorura guangdongensis sp. nov. 1, dorsal side of body; 2, AIIIO; 3, antenna; 4, distal part of leg III; 5, ventral side of Abd. II–IV. Scales: 0.1 mm (1, 3–5), 0.01mm (2). FIGURE 6–11. Thalassaphorura guangdongensis sp. nov. 6, dorsal side of head; 7, PAO; 8, labium; 9, anal valves; 10, Abd. IV–VI terga; 11, central part of Abd. IV sternum. Scales: 0.1 mm (6, 9–11), 0.01mm (7–8). Discussion. T. guangdongensis sp. nov. resembles three known species of the genus as having 1,2,2 pso on Th. I–III terga: T. butrosi ( Christiansen, 1956 ) , T. reducta Sun, Chen & Deharveng, 2010 and T. bapen Sun, Chen & Deharveng, 2010 . It differs from T. butrosi by the pso formulae on the body (32/122/33343 dorsally and 11/000/ 0 1010 ventrally in the new species, versus 32/122/22(1)3(2)3(2)2 dorsally and 1/000/00110 ventrally in T. butrosi ), the number of papillae on AIIIO ( 5 in the new species versus 4 in T. butrosi ), the length of AS (0.6 times as long as inner edge of hind unguis in the new species versus short as small chaetae in T. butrosi ). From T. reducta the new species differs having ventral pso on Abd. IV (absent in T. reducta ), more pso on all subcoxa 1 (2,2,2 in the new species and 1,1, 1 in T. reducta ), chaetae on Th. I sternum (absent in T. reducta ), and longer AS set on distinct papillae (small and without papillae in T. reducta ). T. guangdongensis sp. nov. shares with T. bapen the same pso formulae, the same number of pso on subcoxa1, distal chaetae on tibiotarsi and chaetae on thoracic sterna. Nevertheless these two species can be easily separated by the number of medial chaetae between posterior pso on head (4+ 4 in the new species versus 3+ 3 in T. bapen ), the number of basal chaetae on ventral tube (2+ 2 in the new species versus 1+ 1 in T. bapen ), the ratio of unguiculus/unguis (0.7 in the new species versus 0.4 in T. bapen ), the number of chaetae on Abd. I–III terga along axial line (2+ 2 in the new species and 3+ 3 in T. bapen ), the axial chaetae on Abd. VI tergum (m0 in the new species versus a0 & m0 in T. bapen ).