Macrobiotus kovalevi, Tumanov, 2004

Tumanov, D. V., 2004, Macrobiotus kovalevi, a new species of Tardigrada from New Zealand (Eutadigrada, Macrobiotidae), Zootaxa 406 (1), pp. 1-8 : 2-3

Macrobiotus kovalevi sp. n.

Figs. 1–16 , Tab. 1

Holotype. Adult male, slide number 60(4). Collected by Dr. O. V. Kovalev (Zoological Institute of the Russian Academy of Sciences, St.­Petersburg) 13.02.1992, New Zealand.

Paratypes: slide numbers 60(2), 60(3), 60(5), 60(14), 60(17), 60(22), 60(23), 60(26), 60(27) from the same locality. Holotype and paratypes are preserved at the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia . Other paratypes are preserved in the collection of Binda and Pilato (Department of Animal Biology, University of Catania, Italy.

Type locality. New Zealand, South Island, vicinity of Karamea, Podocarpus forest, moss from tree. Forty­four adult and juveniles and 27 eggs (3 with developed embryos) were found together with specimens of Macrobiotus cf. coronatus and Calcarobiotus (Discrepunguis) sp.

Etymology. this species is dedicated to Dr. O. V. Kovalev, who kindly collected the material for me in New Zealand.

Diagnosis. Smooth cuticle with no pores and granulation on all legs; buccal armature with very short medial ridges dorsally and ventrally; three elongated macroplacoids (third is the longest) and a distinct microplacoid; claws of moderate length with long accessory spines and smooth lunules.

Description. Body length of adult animals 232.8–419.0 m. Body white, often with yellow­brown material in mid­gut. Eye spots present in most specimens. Cuticle smooth without pores and granulation on legs. Buccal cavity lacking teeth in anterior and posterior positions. Transverse ridge system consisting of two latero­dorsal ridges, two latero­ventral ridges, short medio­dorsal ridge and triangular medio­ventral granule ( Figs. 3, 4 , 9, 10 ). Some specimens with wide triangular structures in caudal portion of buccal cavity in front of ventral transverse ridges. Buccal tube narrow with typical strengthening bar ( Figs. 2 , 12, 14 ). Pharyngeal bulb oval with apophyses, three macroplacoids and large microplacoid (for all dimensions see Table 1 ). Claws of hufelandi ­ type ( Figs. 5, 6 , 13 ) with minute stalk, evident distal part of the basal portion and relatively long common tract (terms according to Guidetti & Bertolani, 2001). Primary and secondary branches diverge slightly below half of claw's height, main branches with large accessory points. Claws of fourth pair of legs longer than claws of first three pairs of legs. All claws with smooth lunules, which are slightly larger on claws of fourth pairs of legs. Some specimens with very thin and indistinct cuticular thickening near claw bases of first three pairs of legs.

Eggs spherical, white, ornamented and laid freely ( Figs. 7, 8 , 14–16 ). Chorion with long conical processes. Surface of processes not areolated but covered with irregularly distributed minute spines. Tops of some processes slightly bifurcated. Egg surface between processes covered with reticulation which consists of irregularly distributed polygonal meshes (nearly 1 m in diameter). About 25 processes around circumference of egg. Diameter of eggs (without processes): 86–95 m; height of processes: 12–17 m, their basal diameter: 6.5–9.0 m.

Remarks. The structure of the buccopharyngeal apparatus in Macrobiotus kovalevi is similar to that found in members of harmsworthi and furciger­orcadensis groups of the genus Macrobiotus . It is easily distinguished from all known species of these groups by the structure of the buccal armature (very short medio­dorsal ridge and the absence of typically developed teeth) and unique structure of the egg chorion.

Figures

FIGURES 1–8. Macrobiotus kovalevi sp. nov. 1—habitus, 2—buccopharyngeal apparatus, ventral, 3—buccal armature, dorsal, 4—buccal armature, ventral, 5—claws of the II pair of legs, 6— claws of the IV pair of legs, 7—part of the egg surface, 8—different forms of egg processes (3, 4— holotype; 1, 2, 5, 6—paratypes).

FIGURES 9–16. Macrobiotus kovalevi sp. nov. 9—buccal armature, ventral, 10—buccal armature, dorsal, 11—caudal part of the buccopharyngeal apparatus, 12—anterior part of the body, 13— claw of the III pair of legs, 14, 15—general appearance of the eggs, 16—part of the egg surface (9– 11, 13–16—phase contrast, 12—Nomarsky Optics; 9, 10—holotype, 11–13—paratypes; scale bars: 9–11, 13, 16—10 m, 12, 14, 15—30 m).