Tomocerina annamitica, Man & Deharveng, 2016

Yu, Daoyuan, Man, Le Cong & Deharveng, Louis, 2016, Tomoceridae (Collembola, Entomobryomorpha) from the southern Annamitic cordillera: redescription of Tomocerus ocreatus Denis, 1948 and description of a new species of Tomocerina Yosii, 1955, European Journal of Taxonomy 176, pp. 1-14 : 8-11

Tomocerina annamitica sp. nov.

urn:lsid:zoobank.org:act:9AD947EC-5A05-4385-9A92-8B0DC590A94D

Figs 1B , 4 , 5

Diagnosis

Tomocerina species with typical body size and pigmentation; antennae about 0.8 times as long as body, relatively long for Tomocerina ; Th. II with only one bothriotrichum; tibiotarsi with multiple strong chaetae; tenet hair small and pointed; unguis with 1–2 inner teeth; dental spines compound with denticles; only one distal spine distinctly larger; mucro without intermediate tooth.

Etymology

Specific name derived from its type locality: the southern Annamitic range.

Type material

Holotype

VIETNAM: ♀, on slide. Collected in Hon Giao, Bi Doup massif, northeast of Dalat , Lam Dong Province, 108°42’53”E, 12°11’11’’N, alt. 1630 m, mixed forest litter, 12 Jun. 2008, by Louis Deharveng & Anne Bedos (sample code Vn08-150), deposited in MNHN (specimen Vn08-150_Ta1).

Paratypes

VIETNAM: 2 ♀♀, on slides, same data as holotype, 1 in HCMCU (specimen Vn08-150_Ta2) and 1 in NJAU (specimen Vn08-150_Ta3).

Other material examined

VIETNAM: 5 specimens on slides and 28 specimens in alcohol, collected in the Hon Ba Nature Reserve, Kanh Hoa Province, located 25 km east-southeast of Hon Giao and 25 km south-southwest of Nha Trang, 108°56’55’’– 108°58’51’’E, 12°06’35’’– 12°07’09’’N, mixed forest litter, Nov. 2013, by Louis Deharveng & Anne Bedos: alt. 850 m, Vn13-072 (3 in alcohol); 890 m, Vn13-126 (2 in alcohol), Vn13- 135 (4 in alcohol); 1050 m, Vn13-054 (2 ♀♀, on slides), Vn13-057 (1 Ƌ and 1 ♀, on sildes), Vn13-114 (1 on slide, sex undetermined), Vn13-120 (8 in alcohol); 1350 m, Vn13-039 (5 in alcohol); 1500 m, Vn13-231 (6 in alcohol).

Description

Body length 1.6–1.8 mm. Body colour light grey, antennae light purple, eye patches black, scales brown ( Fig. 1B ). Clothing of Tomocerinae type, similar to that of Tomocerus ocreatus .

PAO not seen. Eyes 6+6. Antenna about 0.75–0.90 times as long as body. Antenna length ratio I:II:III: IV=1.0:1.3–1.5:5.5–6.0:2.2–2.5, Ant. I and Ant. II dorsally scaled, Ant. III and Ant. IV unscaled. Labral formula 4/5, 5, 4, the distal 4 chaetae stronger. Distal edge of labrum with four curved spine-like papillae, ventro-distal brush well developed. Mandibular head asymmetrical, the left one with 4 teeth (including a basal rounded one) and the right one with 5, left molar plate distally with tapered tooth ( Fig. 4A ). Basal teeth of maxillary lamella 5 elongated without beard-like appendage ( Fig. 4B ). Maxillary outer lobe with trifurcate pulp, basal chaeta and 4 sublobal hairs ( Fig. 4C ). Cephalic dorsal chaetotaxy: anterior area: 2, 4; interocular area: 2, 6, central chaeta absent; postocular area: 2+2; posterior area: 2; posterior margin: about 20+20 small chaetae of different sizes ( Fig. 4D ). Both dorsal and ventral side of head scaled. Mentum with 5 chaetae, submentum with numerous chaetae.

Pattern of body chaetotaxy as Fig. 4E . 1, 1 /0, 0, 1, 2, 0, 0 bothriotricha on Th. II–Abd. VI. Macrochaetae densely along anterior margin of Th. II (not shown in figure). Th. II with a row of macrochaetae behind anterior margin. Number of macro- or large mesochaetae in the posterior row as 3, 3, 3, 3, 3, 5, 4 (3 dorsal+1 lateral) from Th. II to Abd. V. On Th. II pseudopore near posterior macrochaeta of the 3 central ones; Th. III with anterior macrochaeta; on Abd. III s-microchaeta posterior to lateral macrochaetae; Abd. IV with antero-lateral macrochaeta and numerous long s-chaetae, 4 inner mesochaetae in posterior row prominent but smaller than outer macrochaeta; on Abd. VI dorsal flap with 2+2 and lateral flap with 3 macrochaetae. Most mesochaetae laterally and posteriorly on terga. Pseudopores near the axis of terga, 1, 1/1, 1, 1, 1, 0, 0 from Th. II–Abd. VI.

Legs with numerous ordinary chaetae. Trochantero-femoral organ with 1, 1 chaetae. Tibiotarsi dorsally with 1, 1, 3 prominent chaetae from front to hind leg, ventrally with 5–7, 4, 5–6 strong chaetae, only 2, 1, 2 of them blunt ( Fig. 4F ). Each tibiotarsus with a distal whorl of 11 chaetae, the dorsal 5 modified: tenent hair pointed, short and thin; 2 accessory chaetae about as long as but thicker than tenent hair, and longer than pretarsal chaetae; 2 outer guard chaetae strong, as long as inner edge of unguis ( Fig. 5 A–C). Scales absent from front and mid tibiotarsi but present on hind tibiotarsus. Unguis slender, lateral teeth of moderate size, internal ridging present. Inner edge of unguis with a small basal and 0–1 larger more distal teeth. Unguiculus about half as long as unguis, without tooth on inner or outer edge. Pretarsus with 1+1 chaetae ( Fig. 5C ).

Ventral tube anteriorly with a few small scales, each side with 20–25 chaetae; posteriorly unscaled, with about 40 chaetae; lateral flap unscaled, each side with about 25 chaetae. Tenaculum with 4+4 teeth, unscaled, anterior face with 1 chaeta about as long as rami ( Fig. 5D ). Ratio manubrium: dens: mucro= 2.0–2.2:2.9–3.2:1.0. Manubrium ventrally with only scales, laterally with scales and 8 chaetae, proximal 2 chaetae small and slender, distal 6 chaetae distinctly stronger; dorsal scales absent; each dorsal chaetal stripe with about 70 chaetae in different sizes, without blunt chaetae; pseudopores 5–6 on each side ( Fig. 5E ); external corner chaeta as large as small chaetae in chaetal stripe ( Fig. 5F ). Dental spines formula 4/3, I, a small pointed scale present ventrally to basal spines; all spines with several large denticles near base, superficial texture different between dorsal and ventral sides: dorsally with only fine longitudinal ribs, ventrally with longitudinal ribs and distal tiny serrations ( Fig. 5G ). The largest spine about 0.1 times as long as dens. Dens dorsally with feather-like chaetae between ordinary chaetae. Stripe of feather-like chaetae starting from centre of middle subsegment of dens, ending a short distance to the apex of dens. Ventral side of dens covered by scales, several chaetae present apically. Mucro elongated and multisetaceous, with two dorsal lamellae; both basal teeth with proximal lamellae, outer tooth without toothlet; apical tooth elongated, stronger than subapical tooth; intermediate teeth absent ( Fig. 5H ).

Remarks

Among Tomocerina , the new species is similar to those of the minuta group in its small body size, grey body colour and shape of mucro, but is different from them mainly in the chaetotaxy and the shape of dental spines. It is similar to Tomocerina purpurithora Liu, Hou & Li, 1999 from Sichuan Province, China in the shape of dental spines, but is different from the latter mainly in the cephalic chaetotaxy, the number of tibiotarsal strong inner chaetae, the number of chaetae on tenaculum, the dental spines formula and the number of teeth on mucro ( Table 1 ). Tomocerina annamitica sp. nov. is the southernmost distributed species of Tomocerina , a genus mostly diversified in northern temperate to cold temperate regions. However, so far Tomocerina is poorly defined by only a minute character: the absence of corner toothlet on outer basal tooth of mucro. In this respect, the presence of only 1+1 bothriotricha on Th. II of Tomocerina annamitica sp. nov. might provide an interesting character, while most other species of Tomocerinae have 2+2. Investigation on this character in different groups of Tomocerinae is in progress to assess its phylogenetic value.

Figures

Fig. 1. Appearance of Tomocerus ocreatus Denis, 1948 and Tomocerina annamitica sp. nov. in alcohol. A. Tomocerus ocreatus (lateral view). B. Tomocerina annamitica sp. nov. (lateral view). Scale bar: 1 mm.

Fig. 4. Tomocerina annamitica sp. nov. A. Apical half of mandibular head (dorsal view). B. Lamella 5 of maxillary head (dorsal view). C. Maxillary outer lobe (ventral view). D. Cephalic dorsal chaetotaxy. E. Dorsal chaetotaxy of Th. II–Abd. VI. F. Left tibiotarsi (lateral view, b = blunt inner chaeta). Scale bars: A, C = 50 μm; B = 10 μm; D, E = 250 μm; F = 100 μm.

Fig. 5. Tomocerina annamitica sp. nov. A. Diagram of tibiotarsal distal chaetae (distal view). B. Tibiotarsal distal chaetae (dorsal view). C. Hind claw (lateral view). D. Tenaculum (anterior view). E. Left side of manubrium (dorsal view). F. Disto-external corner of manubrium (dorsal view). G. Basal and middle subsegments of dens with dental spines (dorsal view, 1 = ventral side of spine, showing only distal serrations; 2 = dorsal side of spine, showing fine longitudinal ribs; s = small inner scale). H. Mucro (inner view). Scale bars: B–D = 20 μm; E–H = 50 μm.