Calcarobiotus (Discrepunguis)

Tumanov, D. V., 2004, Macrobiotus kovalevi, a new species of Tardigrada from New Zealand (Eutadigrada, Macrobiotidae), Zootaxa 406 (1), pp. 1-8 : 5-7

Calcarobiotus (Discrepunguis) sp.

Figs. 17–30

Body length 289.3 m. Eye spots absent. Cuticle smooth without pores and granulation on legs. Mouth opening surrounded with 10 peribuccal lamellae. Buccal armature with two latero­dorsal ridges, two latero­ventral ridges, long medio­dorsal and medio­ventral ridges ( Figs. 19, 20 , 26, 27 ). With band of well developed triangular teeth in caudal portion of buccal cavity in front of transverse ridges. Buccal tube wide, with typical strengthening bar (buccal tube length 40 m, width 6.2 m, pt index for the insertion point of stylet supports – 78%) ( Figs. 18 , 24, 25 ). Pharyngeal bulb oval, contains apophyses, three macroplacoids and large microplacoid. Macroplacoid lengths: first 4 m, second 3.9 m, third 5 m. Microplacoid length 3.7 m. Macroplacoid row length 16 m. Placoid row length 20.7 m. Claws of the first three pairs of legs typical to that found in members of Discrepunguis subgenus of the genus Calcarobiotus : primary and secondary branches are of similar length, connected near claw base, common tract very short and slightly widened ( Figs. 21, 22 ). Main branches with poorly developed accessory points. Claws of fourth pair of legs longer then claws of the first three pairs of legs, with longer common tract and well differentiated primary and secondary branches. All claws with smooth lunules, which are slightly larger on claws of the fourth pairs of legs. Weakly developed cuticular bars seem to be present below claw bases of claws of the first three pairs of legs. Claw heights: legs II – 9.7 m (pt =24.3), legs IV – 11 m (pt =27.5).

One egg was found, spherical, white, about 100 m in diameter ( Figs. 23 , 29–30 ). Egg chorion with thin, elongate conical processes. Processes 15–17 m long, base diameter 6.5–9 m, often with 1–3 transverse septae inside. Tops of some processes bifurcated. Egg surface between processes covered with evident sculpture consisted of closely distributed flat granules (nearly 0.5 m in diameter). Base of each process with 1–4 large pores (0.8– 1.1 m in diameter) around base and close to it. Wider ring, consists of 5–8 small pores (nearly 0.5 m in diameter) also around base of each process. Egg shell nearly 2 m thick and divided in two layers: thick external (nearly 1 m) and thin internal (nearly 0.5 m). Space between them with numerous pillars, connecting these layers. The only free egg found lacks developed embryo, but two developed eggs, visible in the ovary of adult animal ( Fig. 28 ) have very similar chorion structure (elongate conical processes with internal transverse septae, large pores around base of processes).

Remarks. On the basis of the morphology of the adult specimen Calcarobiotus sp. is similar to the members of Discrepunguis subgenus of the genus Calcarobiotus . It is easily distinguished from Calcarobiotus (Discrepunguis) eugranulatus (Maucci) and C. (D.) polygonatus (Binda & Guglielmino) in having completely smooth cuticle. It seems to be a new species, but taking into account the poor state of the single specimen found and some differences in the morphology of free­laid egg and eggs in the female ovary this species could not be described as a valid species without finding of the additional material.

Figures

FIGURES 17–23. Macrobiotus sp. 17—habitus, 18—buccopharyngeal apparatus, ventral, 19— buccal armature, dorsal, 20—buccal armature, ventral, 21—claws of the II pair of legs, 22—claws of the IV pair of legs, 23—part of the egg surface.

FIGURES 24–30. Macrobiotus sp. 24, 25 – buccopharyngeal apparatus, 26 – buccal armature, dorsal, 27 – buccal armature, ventral, 28 – part of the surface of the unlaid egg, 29 – part of the egg surface, 30 – general appearance of the egg (24 – Nomarsky Optics, 25–30 – phase contrast; scale bars: 24, 25, 29, 30 – 20 m, 26–28 – 10 m).