Pseudechiniscus papillosus, Li & Wang & Liu & Su, 2005

Li, Xiaochen, Wang, Lizhi, Liu, Ying & Su, Lina, 2005, A new species and five new records of the family Echiniscidae (Tardigrada) from China, Zootaxa 1093 (1), pp. 25-33 : 30-32

Pseudechiniscus papillosus sp. nov. ( Fig. 3A–E , Table 1)

Material examined: Holotype (Slide number MTB05080762), two paratypes (Slide number MTB05080761, MTB05080763) were collected from Mount Taibai at an altitude of 3,760 m a.s.l. (33°57.32’ N, 107°45.94’ E). The specimens are deposited at the College of Life Sciences, Shaanxi Normal University, P. R. China.

Diagnosis: Colour red. Cephalic appendages include internal buccal cirrus, very short and wide cephalic papilla, external buccal cirrus, cirrus A, and clava. Armor consists of single cephalic plate, scapular plate, first single median plate, first paired­plates, second single median plate, second paired­plates, third single median plate, pseudosegmental plate with two lobes on the posterior edge, and terminal plate with usual two notches; scapular plate divided transversely into an anterior part and a posterior part. All plates decorated with papilla­like projections; papilla­like projections absent on ventral side; lateral side near the base of legs also decorated with papilla­like projections, but much smaller than the ones on dorsal plates. Papilla present near the base of the fourth pair of legs. Spurs absent on all claws of each leg.

Description of the holotype: Colour red. Eyespots not detected. Cephalic appendages include internal buccal cirrus, cephalic papilla very short and wide, external buccal cirrus, cirrus A, and clava. No other appendages present ( Fig. 3A–B ). Dorsal plates covered with papilla­like, uniformly distributed projections varying in size, diameter of 2.0– 2.6 m, height of 3.8–4.8 m ( Fig. 3C ).

Cephalic plate faceted; armor consists of single cephalic plate, scapular plate, first single median plate, first paired­plates, second single median plate, second paired­plates, third single median plate (all median plates undivided), pseudosegmental plate subdivided along the mid­sagittal plane of the body, the pseudosegmental plate with two lobes on the posterior edge, the lobes triangle­shaped with one point directed backward, and terminal plate with the two usual notches; scapular plate transversely divided into an anterior part and posterior part; all plates decorated with many papilla­like projections varying in size ( Fig. 3C ), absent on ventral side.

Legs normal length, a papilla (length 4.7 m) present on the external side of the fourth pair of legs near their bases. Lateral side near the base of legs covered with many papillalike projections much smaller than the ones on the dorsal plates. Claws normally curved distally, without spurs near the bases of the claws on each leg ( Fig. 3D–E ).

Eggs unknown.

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

Etymology: This species is named after the papilla­like sculpture of the cuticle.

Differential diagnosis: Kristensen (1987) distinguishes two groups in the genus Pseudechiniscus : the suillus or conifer group without cirri B–E, and the victor group with cirri or spines B–E. Pseudechiniscus papillosus sp. nov. belongs to the suillus / conifer group and differs from all known species of the genus Pseudechiniscus by the papilla­like projections on both dorsal plates and legs.

Compared with other species of the suillus /conifer group, Pseudechiniscus papillosus sp. nov. is similar to P. spinerectus Pilato et al., 2001 in having divided scapular plate, but it differs from it in lacking ventral sculpture, in having different cuticular sculpture, in having undivided median plates, in having lobes instead of spines on the posterior edge of pseudosegmental plate, and in having no spurs on the fourth claws.

This new species differs from Pseudechiniscus rammazzottii Maucci, 1952 in having different cuticular sculpture, in having undivided median plates and transversely divided scapular plate.

This new species differs from P. asper Abe et al., 1998 in having different cuticular sculpture and in lacking segmental lateral plates on scapular plate and paired­plates.

Figures

FIGURE 3. A–E, Pseudechiniscus papillosus sp. nov. (holotype): A–B, habitus; C, cuticular sculpture; D, claws on leg II; E, claws on leg IV. (A: phase contrast). A–B, scale bars = 50 m; C–E, scale bars = 10 m.