Minibiotus wuzhishanensis, Li & Wang & Wang, 2008

Li, Xiao-Chen, Wang, Da-Yong & Wang, Li-Zhi, 2008, The Tardigrada Fauna Of Hainan Island (Asia: China) With Descriptions Of Two New Species, Raffles Bulletin of Zoology 56 (2), pp. 293-305 : 299-301

Minibiotus wuzhishanensis , new species

( Figs. 11–20 , Table 3)

Material examined. – Holotype (Slide number: Hi0704040), 2 paratypes (Slide numbers: Hi0704050, Hi0704041) from Five-

Body length 210.0 270.0 280.0 300.0 320.0 Buccal tube length 23.4 26.0 26.0 28.6 29.9 Buccal tube width 2.1 8.97 2.3 8.85 2.1 8.08 2.6 9.09 2.6 8.7 Stylet support insertion point 15.6 66.67 16.9 65.0 15.6 60.0 20.0 70.0 20.8 69.57 First macroplacoid length 5.2 22.22 5.2 20.0 5.2 20.0 5.2 18.18 7.8 26.09 Second macroplacoid length 2.8 11.97 4.2 16.15 3.1 11.92 3.1 10.84 3.4 11.37 Macroplacoid row length 8.3 35.47 10.4 40.0 8.6 33.08 10.4 36.36 13.0 43.48 Microplacoid length 1.0 3.85 1.0 3.85 1.0 3.64 1.2 3.91 Placoid row length 11.7 45.0 9.9 38.0 11.7 40.91 14.6 48.7 Leg 1 external claw PBL 6.5 27.78 7.8 30.0 7.8 30.0?? 7.8 26.09 Leg 1 external claw SBL?? 5.7 21.92 6.5 25.0???? Leg 1 internal claw PBL?????? 7.8 27.27 7.8 26.09 Leg 1 internal claw SBL?????? 7.3 25.52?? Leg 2 external claw PBL?? 7.8 30.0?? 7.8 27.27 8.3 27.76 Leg 2 external claw SBL?? 6.5 25.0?? 7.3 25.52?? Leg 2 internal claw PBL???? 7.8 30.0???? Leg 2 internal claw SBL???? 6.5 25.0???? Leg 3 external claw PBL 7.5 32.05?? 8.1 31.15 7.8 27.27 8.6 2 8.76 Leg 3 external claw SBL 6.5 27.78?? 7.3 28.08 7.3 25.52?? Leg 3 internal claw PBL?? 8.3 31.92?????? Leg 3 internal claw SBL?? 7.3 28.08?????? Posterior claw 4 PBL 7.8 33.33 9.1 35.0 10.4 40.0 8.6 30.07 9.6 32.11 Posterior claw 4 SBL 5.2 22.22 7.8 30.0 8.6 33.08 7.3 25.52 7.8 26.09 Anterior claw 4 PBL 7.3 31.2???? 8.6 30.07 9.1 30.34 Anterior claw 4 SBL 5.2 22.22???? 7.3 25.52 7.5 25.08

Abbreviations: PBL, primary branch length; SBL, secondary branch length.

Finger Mountain (18°52.920'N 109°39.698'E) at 1,200 m a.s.l. Two additional specimens (Slide numbers: Him0704001, Him0704002) from Mumianshan Mountain (19°15'N 109°20'E) at 300 m a.s.l., coll. Xiao-Chen Li, Da-Yong Wang & Li-Zhi Wang, 20 Apr.2007. All specimens were mounted in Hoyer’s medium .

Description. – Colourless. Eyes present. Cuticular sculpture composed of many knob-shaped cuticular thickenings different in size and shape better-developed in the posterior part of the body (1.5–6.0 µm). Thickenings irregularly distributed and arranged in 7 transverse bands on dorsal and lateral side of the body. In some specimens, three short longitudinal smooth bands present on the posterior margin of the last band of the cuticular thickenings, making an appearance of four gibbosities along the posterior edge; while in other bands, two short longitudinal smooth bands present on dorsolateral sides of the bands, divide each band into three parts ( Figs. 11 , 17 ). Above of each hind leg, one gibbosite present. The third gibbosite present at the terminal end of the body ( Fig. 12 ).

Bucco-pharyngeal apparatus of Minibiotus type with 10 peribuccal papillae, buccal tube rigid with ventral lamina. Buccal tube wide. Pharynx oval with apophyses and two rod-shaped macroplacoids. The first macroplacoid with middle constriction much longer than the second one. The first macroplacoid narrower at the anteiror part. The second macroplacoid with subterminal constriction. Microplacoid usually present but very small, sometimes absent, septulum absent ( Figs. 14 , 18 ).

Claws of hufelandi type. All claws with smooth lunules. Primary branches of all claws with well-developed accessory points. Cuticular bars absent ( Figs. 13 , 15–16 , 19–20 ).

Eggs unknown.

Etymology. – This species is named after the type locality (Five-Finger Mountain is spelled as wuzhishan in Chinese phonetic writing).

Remarks. – Measurements of all found specimens are given in Table 3

Differential diagnosis. – Up until now only three species of the genus Minibiotus with two macroplacoids have been described: Minibiotus africanus Binda & Pilato, 1995 , M. fallax Pilato, Claxton & Binda, 1989 , and M. scopulus Claxton, 1998 . Minibiotus wuzhishanensis , new species, differs from M. africanus (Binda & Pilato, 1995) in having cuticular thickenings on dorsal and lateral side of the body instead of little circular and a little bigger elliptical pearls on dorsal and ventral sides. This new species also differs from Minibiotus africanus by a wider buccal tube (buccal tube width of the holotype of M. africanus is 1.48 µm, while the average buccal tube width of the new species is 2.3 µm). This new species differs from M. fallax ( Pilato et al., 1989) by: lacking of cuticular pores, pearls, gibbosities on dorsal side of the body, having cuticular thickenings on dorsal and lateral side of the body instead of gibbosities and having three gibbosities at posterior end of the body. The new species is smaller than M. fallax (The body length of the largest specimen of the new species is 320 µm, while the body length of M. fallax is up to 395 µm). Minibiotus wuzhishanensis , new species, differs from M. scopulus ( Claxton, 1998) by having cuticle with knob-shaped thickenings and without pores. The new species is smaller in body size and shorter in buccal tube length than M. scopulus (The average body length of the new species is 276 µm, while 328.9 µm in M. scopulus ; the average buccal tube length of the new species is 26.8 µm, while 30.9 µm in M. scopulus ).

Figures

Figs. 11–13. Minibiotus wuzhishanensis, new species (holotype): 11, habitus focused to show the cuticular sculpture; 12, habitus focused to show the gibbosities in terminal end of the body; 13, habitus focused to show the claws. Figs. 11–13: scale bars = 50 µm.

Figs. 14–17. Minibiotus wuzhishanensis, new species: 14, buccal apparatus (paratype, slide number Hi0704041); 15, claws on the second pair of legs (holotype); 16, claws on the hind legs (paratype, slide number Hi0704041); 17, cuticular sculpture (holotype). Figs. 14–17 scale bars = 10 µm.

Figs. 18–20. Minibiotus wuzhishanensis, new species: 18, buccal apparatus (paratype, slide number Hi0704041); 19, claws on the second pair of legs (holotype); 20, claws on the hind legs (paratype, slide number Hi0704041). Figs. 18–20 scale bars = 10 µm.