Isohypsibius panovi, Tumanov, Denis V., 2005

Tumanov, Denis V., 2005, (Eutardigrada, Hypsibiidae), Zootaxa 812, pp. 1-4 : 1-3

Isohypsibius panovi sp. n. ( Figs. 1–8 , Tab. 1 )

Holotype. Slide number 222(4) (sex indet). Collected by Dr. V. E. Panov (Zoological Institute of the Russian Academy of Sciences, St.­Petersburg) 24.09.2004, Republic of Ireland.

Paratypes. Three specimens (slide’s numbers 222(1), 222(2), 222(3)) from the same location.

Type locality. Republic of Ireland, Clare county, vicinity of Bellharbour, lichen from sandy soil. Eight adults (1 in simplex stage) and 1 exuvium with 3 eggs were found.

Etymology. This species is dedicated to Dr. V. E. Panov, who kindly collected the material for me in Ireland.

Description. Body length 315.9–389.0 m. Body white. With small black eyespots. Cuticle smooth ( Figs. 1 , 5 ).

Bucco­pharyngeal apparatus of Isohypsibius type (according to Pilato (1982)) ( Figs. 2 , 6 ). Buccal armature consists of poorly developed paired latero­dorsal transversal crests, largest specimens with indistinct short medio­dorsal crest. Pharyngeal bulb oval and with large apophyses and two macroplacoids. No microplacoids. First macroplacoid the longest and distinctly constricted in the middle.

Legs with small claws typical to the Isohypsibius genus ( Figs. 3, 4 , 7, 8 ), slightly increasing in size from legs I to IV. All claws with very poorly developed accessory points (almost invisible in the internal claws), narrow bases and small smooth lunules. No cuticular bars near claw bases on legs I­III. Distinct cuticular bars with thickened outer edges developed at the bases of the internal claws on the hind legs.

One exuvium with 3 smooth oval eggs (74.0 x 55.5 m) was found.

Differential diagnosis. Isohypsibius panovi sp. n. differs from all known Isohypsibius species with smooth cuticle and two macroplacoids ( Isohypsibius borkini Tumanov , Isohypsibius chiarae Maucci , Isohypsibius dastychi Pilato, Bertolani and Binda , Isohypsibius jakieli Dastych and Isohypsibius marcellinoi Binda and Pilato ) in the absence of cuticular bars on legs I­III.

Cuticular bars on legs IV are mentioned only in the descriptions of Isohypsibius chiarae Maucci, 1987 and Isohypsibius bertolanii Manicardi, 1989 , their orientation is not mentioned in the original description of I. chiarae , but it is evident from the photograph ( Maucci 1987, Fig. 9), that it is identical to that in I. bertolanii . Isohipsibius panovi sp. n. differs from these species in having increasing claw length from legs I to IV, in lacking cuticular bars on legs I­III, and in having cuticular bars on legs IV developed only at the bases of internal claws. It also differs from I. bertolanii in having smooth cuticle.

It needs to be noted that cuticular bars on legs IV could be more widely distributed within Isohypsibius genus. Besides I. bertolanii , I. chiarae and I. panovi sp. n. poorly developed cuticular bars near the bases of both claws of legs IV were found by me in I. borkini (not included in the original description (Tumanov 2003)) and near the bases of internal claws in Isohypsibius sp. gr. elegans from Spitsbergen.

Figures

FIGURES 1 – 4. Isohypsibius panovi sp. nov. 1 – habitus, 2 – bucco­pharyngeal apparatus, dorsal view, 3 – claws of the II pair of legs, 4 – claws of the IV pair of legs, (1, 2 – holotype; 3, 4 – paratypes).

FIGURES 5 – 8. Isohypsibius panovi sp. nov. 5 – habitus, 6 – bucco­pharyngeal apparatus, 7 – claws of the II pair of legs, 8 – claws of the IV pair of legs (phase contrast; 5 – 8 – paratypes).