Isohypsibius condorcanquii Kaczmarek, Cytan, Zawierucha, Diduszko & Michalczyk, 2014, sp. nov.

Isohypsibius condorcanquii sp. nov.

(Table 1, Figs 1–5)

Localities and number of specimens: II (8). Material examined. Holotype (slide PE2002/2), seven paratypes (animals) (slides: PE2002/6, PE2002/8, PE2002/12) and one simplex (slide PE2002/5)

Description (measurements and statistics in Table 1). Animals: Body transparent/white, eyes absent (in specimens mounted in Hoyer’s medium (Fig. 1). Dorsal cuticle, including dorso-caudal portion of legs IV, covered with small polygonal tubercles 0.8–1.2 Μm in diameter (Fig. 2). Spaces between the tubercles form a reticulum of grooves. Ventral cuticle smooth (i.e. without sculpturing). Gibbosities and cuticular pores absent.

Bucco-pharyngeal apparatus of the Isohypsibius type, without the ventral lamina (Fig. 3). Peribuccal lamellae absent. Oral cavity armature composed of two clearly visible round ventral teeth (sometimes a third, weakly developed tooth is also present) (Fig. 3, insert). Pharyngeal bulb with long, triangular apophyses and with three granular macroplacoids (all without constrictions). Macroplacoid length sequence 1<2<3. Microplacoid and septulum absent.

Claws of the Isohypsibius type, similar in size and shape on all legs (Figs 4–5). All primary branches with minute accessory points (sometimes not visible in poorly preserved/oriented specimens). Proper lunules at the bases of external claws absent; but in some specimens a small, smooth areola is visible under the claw. Bars and other cuticular structures on legs absent.

Eggs: Unknown.

Remarks. In some specimens, smooth and poorly visible areolae can be seen under external and internal claws (appearing as poorly outlined lunules). Thus, the presence or absence of lunules in this species could be difficult to determine, especially when only small number of specimens are available for examination.

Etymology. The new species is named in honour of Gabriel Condorcanqui (Tupac Amaru II), an indigenous Peruvian leader of a 1780 uprising against the Spanish colonisers.

Type locality. 13°10'S; 72°33'W, ca. 2,450 m asl: Cusco Region, Machu Picchu, moss from rock, 27.10.2010, coll. Dawid Diduszko.

Type depositories. Holotype (slide PE2002/2), seven paratypes (slides: PE2002/6, PE2002/8, PE2002/12 and one exuvium (PE2002/5) are deposited at the Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, A. Mickiewicz University in Poznań, Umultowska 89, 61–614 Poznań (Poland).

Differential diagnosis. By having three macroplacoids in the pharynx and dorsal cuticle covered with small individual structures such as tubercles, granules or thickenings, the new species is most similar to the following species, but differs from:

Isohypsibius asper (Murray, 1906) , known from the Antarctic and the Palearctic (McInnes 1994), by: a different type of cuticular sculpture (polygonal tubercles in the new species vs. hemispherical thickenings in I. asper), smaller claws IV, and the absence of eyes.

Isohypsibius baldii (Ramazzotti, 1945), known only from Italy and Faroe Islands (Ramazzotti 1945, Trygvadóttir & Kristensen 2013), by the absence of ventral sculpture, a different macroplacoid length sequence (1<2<3 in the new species vs. 2<1<3 in I. baldii), and differently shaped macroplacoids (granules in the new species vs. rods in I. baldii).

Isohypsibius damxungensis Yang, 2007 , known only from China (Yang 2007), by: a different type of the cuticular sculpture (polygonal tubercles in the new species vs. rectangular or round granules of different sizes in I. damxungensis), a slightly smaller body size (131–332 Μm in the new species vs. 324–399 Μm in I. damxungensis), and the absence of eyes.

Isohypsibius granulifer granulifer Thulin, 1928, known from the Holarctic and the Neotropic (McInnes 1994), by: a different type of cuticular sculpture (polygonal tubercles in the new species vs. irregularly distributed thickenings in I. g. granulifer), and by a slightly different macroplacoid length sequence at the population level (1<2<3 in the new species vs. 1≤2<3 in I. g. granulifer).

Isohypsibius granulifer koreanensis (Iharos, 1971) , known only from North Korea (Iharos 1971), by: the absence of ventral sculpture and by a different type of dorsal cuticular sculpture (polygonal tubercles in the new species vs. irregularly distributed granules in I. g. koreanensis).

Isohypsibius kenodontis Kendall-Fite & Nelson, 1996 , known only from the USA (Kendall-Fite & Nelson 1996), by: a different type of the cuticular sculpture (polygonal tubercles in the new species vs. partially fused minute granules forming a reticulum in I. kenodontis), a different macroplacoid length sequence (1<2<3 in the new species vs. 2<1<3 in I. kenodontis), the presence of the oral cavity armature, and by the absence of eyes.

Isohypsibius ladogensis Tumanov, 2003 , known only from Russia (Tumanov 2003), by: a different type of cuticular sculpture (polygonal tubercles in the new species vs. indistinct irregular tubercles fused into a reticulum in I. ladogensis), a different macroplacoid length sequence (1<2<3 in the new species vs. 2<1<3 in I. ladogensis), and by the absence of thin cuticular bars under claws I–III.

Superfamily: Macrobiotoidea Thulin, 1928 in Marley et al. 2011

Family: Macrobiotidae Thulin, 1928

Genus: Macrobiotus C.A.S. Schultze, 1834