Milnesium katarzynae, Kaczmarek, Łukasz, Michalczyk, Łukasz & Beasley, Clark W., 2004

Kaczmarek, Łukasz, Michalczyk, Łukasz & Beasley, Clark W., 2004, Milnesium katarzynae sp. nov., a new species of eutardigrade (Milnesiidae) from China, Zootaxa 743, pp. 1-5 : 2-4

Milnesium katarzynae sp. nov.

Figs. (1–7)

Holotype

Total body length 294.5 (paratype: 285.0) ( Fig. 1 ). Body white, eyes absent. Cuticle segmented by irregular folds (rings). Dorsal side of the body with fine reticular design (diameter of polygons 0.5–1.0) better developed in caudal end ( Fig. 5 ). Six peribuccal and two lateral papillae present. Peribuccal lamellae invisible in mounted animals due to retraction of buccal tube. Buccal tube 30.4 (28.5) long and 6.6 [21.7] (7.6 [26.6]) wide. Stylet supports inserted on buccal tube at 23.8 [78.3] (20.9 [73.3]). Pharyngeal bulb elongated and pear­shaped. Placoids and septula in pharyngeal bulb absent ( Figs 2 , 6 ). Claws of Milnesium type (main branch completely separated from secondary one), almost the same in length on first three pair of legs and slightly longer on fourth. Main branch with small accessory points, secondary with two points on all legs. Claw lengths: external leg I: main branch: 12.4 [40.7] (11.4 [40.0]), claw base + secondary branch 8.1 [26.6] (7.6 [26.7]); external leg II: mb. 12.4 [40.7] (11.4 [40.0]), cbsb. 8.6 [28.3] (7.6 [26.7]); external leg III: mb. 12.4 [40.7] (11.9 [41.8]), cbsb. 8.6 [28.3]; external leg IV: mb. 13.3 [43.8] (12.4 [43.5]), sbsb. 8.6 [28.3] (7.6 [26.7]) ( Figs 3–4 , 7 ). Long transversal, cuticular bars on first three pair of legs present. Eggs unknown.

Type Locality

China, Sichuan Province, Kangding Nature Reserve, moss from tree, 2600 m asl (holotype), moss from wet soil near Wildman Lake, 3800 m asl (paratype), August 2002, Leg. Ms. Katarzyna Ratyńska

Type Repositories

The holotype (No CH 8.1) is deposited in the Research Center of Animal Evolution and Systematics, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China. The paratype (No CH 13.2) is preserved at the Department of Animal Taxonomy and Ecology, A. Mickiewicz University, Poznań, Poland.

Differential Diagnosis

Milnesium katarzynae sp. nov. differs from the majority of described species of the genus Milnesium by the presence of reticular design on the dorsal side of the body, absence of eyes (specimens of the new species were not observed alive and it is possible that eyes were present but they have dissolved during the preparation, however in the same material specimens of Milnesium tardigradum were also found and all have eyes after the preparation), and having claws of almost the same size on all legs. M. katarzynae sp. nov. is similar to the specimens of M. tardigradum described by Nelson & Horning (1979) from New Zealand with reticular shallow depressions in cuticle but is clearly different by lacking eyes and having a lower pt of the buccal tube width (pt = 21.7–26.6 in the new species and pt = 41.9 in the specimens collected in New Zealand). The new species differs also from M. reticulatum (with reticular design on the dorsal side of the body) by lacking gibbosities and eyes and having stylet supports inserted in more caudal position (73.3–78.3 in M. katarzynae sp. nov. and 68.5–69.8 in M. reticulatum ).

Figures

FIGURES 1 – 5. Milnesium katarzynae sp. nov. 1 — habitus, 2 — buccal apparatus, 3 — internal claws of IV pair of legs, 4 — external claws of IV pair of legs, 5 — dorsal cuticle sculpture.

FIGURES 6 – 7. Milnesium katarzynae sp. nov. 6 — buccal apparatus, 7 — claws of IV pair of legs.