Isohypsibius qinlingensis, Li & Wang & Yu, 2005

Li, Xiaochen, Wang, Lizhi & Yu, Di, 2005, Isohypsibius qinlingensis sp. nov. (Tardigrada, Hypsibiidae) from China, Zootaxa 980 (1), pp. 1-4 : 2-4

Isohypsibius qinlingensis sp. nov. ( Fig. 1 , measurements of holotype in table 1)

Material examined: Holotype (Slide number QL05001) and four paratypes (Slide numbers QL05002–05005) were collected from Qinling Mountains at an altitude of 1 450 m

a.s.l. (34°9’ N, 108°57’ E). All specimens are deposited at the College of Life Sciences, Shaanxi Normal University, P. R. China .

Diagnosis: Colourless. Dorsal surface with eight transverse rows of large gibbosities: two gibbosities in rows 2, 4, 6, 7 and 8, and three in rows 1, 3 and 5. Cuticle on dorsal side with 18 transverse undulations, remarkably different in width, dorsal and lateral cuticle densely dotted with small hemispherical tubercles. Pharyngeal bulb with two rod­shaped macroplacoids. First macroplacoid, with a central constriction, much longer than second one. Accessory points invisible on claws.

Description of the holotype: Colourless. Eye spots absent. Dorsal surface with eight transverse rows of large gibbosities: two gibbosities in rows 2, 4, 6, 7 and 8, and three in rows 1, 3 and 5. Gibbosities different in size but smallest in row 8 ( Fig. 1A–B ). Cuticle on dorsal side with 18 transverse undulations, remarkably different in width, dorsal and lateral cuticle densely dotted with small hemispherical tubercles, different in size, maximum diameter of tubercle over 2.6 µm ( Fig. 1A, G ). Mouth without peribuccal lamellae. Stylet furcae ( Fig. 1F ) triangular in shape, with the posterior­lateral vertices elongated into two rod­shaped processes, whose apices rounded and swollen. Bucco­pharyngeal apparatus of Isohypsibius type (according to Pilato, 1982) ( Fig. 1C ). Pharyngeal bulb oval, buccal tube rigid; stylet supports inserted on the buccal tube at 66.67% of its length. Pharyngeal bulb with small apophyses and two rod­shaped macroplacoids. First macroplacoid, with a central constriction, much longer than second one. Microplacoid absent.

Claws of Isohypsibius type ( Fig. 1D–E ) without lunules and cuticular bars, slightly increasing in size from leg I to IV. Accessory points invisible on claws.

Eggs unknown.

Remarks: The paratypes are similar to the holotype as regards the qualitative characters.

Etymology: Named after the type locality, Qinling Mountains.

Differential diagnosis: The new species differs from all known Isohypsibius species with large gibbosities and two macroplacoids in the number and arrangement of gibbosities in each row. Isohypsibius qinlingensis sp. nov. is similar to Isohypsibius roncisvallei ( Binda & Pilato, 1969; Ramazzotti & Maucci, 1983), but it differs from it in having different arrangement of the gibbosities. The former has configuration 3­2­3­2­3­2­2­2, while the latter has configuration 2­3­2­3­2­3­2­2 (from row 1 to row 8). The new species also differs from I. roncisvallei in having densely arranged small tubercles on dorsal and lateral cuticle.

Figures

FIGURE 1. Isohypsibius qinlingensis sp. nov.: A–B, habitus from dorsal view showing the gibbosities (holotype); C, bucco­pharyngeal apparatus (holotype); D, double­claws on the 2nd pair of legs (holotype); E, doubleclaws on the 4th pair of legs (holotype); F, stylet furca (paratype, slide number QL05002); G, cuticular sculpture (holotype). (A: phase contrast). A–B, scale bars = 30µm; C, scale bar = 10µm; D–G, scale bars = 5µm.