New tardigrade records for the Baltic states with a description of Minibiotus formosus sp. n. (Eutardigrada, Macrobiotidae) Author Zawierucha, Krzysztof Author Dziamiecki, Jakub Author Jakubowska, Natalia Author Michalczyk, Lukasz Author Kaczmarek, Lukasz text ZooKeys 2014 408 81 105 http://dx.doi.org/10.3897/zookeys.408.6612 journal article http://dx.doi.org/10.3897/zookeys.408.6612 1313-2970-408-81 D5A553D75B78430489716A0CF73FC698 Hypsibius cf. scabropygus Cuenot , 1929 Table 1, Figs 1-7 Localities and specimen numbers. XI: 1 simplex, XII: 1 specimen, XIV: 34 specimens (including 4 simplexes), XV: 24 specimens (including 6 simplexes). Description (measurements in Table 1). Adults. Body transparent/white (after preparation), eyes present in 6 of 15 (40%) specimens mounted in Hoyer's medium (Fig. 1). Dorsal cuticle sculptured: from head to legs II without tubercles but clearly thickened, from legs II to the caudal end of the body (including legs IV) with irregular tubercles and platelets. Tubercles increasing in size from the anterior to the posterior part of the body, reaching maximum dimensions between legs III and IV, where tubercles sometimes merge and form irregular platelets (Figs 2-5). Irregular tubercles 1.0-6.0 μm in diameter. Ventral cuticle smooth (i.e. without sculpturing). Gibbosities and cuticular pores absent. Figures 1-5. Hypsibius cf. scabropygus Cuenot , 1929: 1 habitus (dorso-lateral view) 2-4 caudo-dorsal cuticle with distinct sculpturing - tubercles and tubercles merged into platelets 5 a single caudo-dorsal platelet. (1-3: PCM, 4-5: SEM). Table 1. Measurements and pt values of selected morphological structures of Hypsibius cf. scabropygus Cuenot , 1929 mounted in Hoyer's medium (N - number of specimens/structures measured, RANGE refers to the smallest and the largest structure among all measured specimens; SD - standard deviation).

CHARACTER	N	RANGE						MEAN		SD
		µm			pt			µm	pt	µm	pt
808	1132	949	97
51.3	57.1	54.9	1.6
6.5	8.0	7.2	0.5
2.1	3.4	2.7	0.4
7.7	12.3	9.6	1.3
7.2	11.3	8.9	1.1
19.1	26.5	21.7	1.8
9.1	17.2	14.1	2.1
18.2	36.1	28.1	5.0
10.5	24.4	17.9	3.9
9.3	15.5	13.4	1.8
16.0	23.5	19.3	2.0
9.9	16.5	13.3	2.0
12.4	19.9	16.7	2.2
29.7	43.7	34.7	4.4
19.0	27.2	21.9	2.6
10.9	18.9	14.6	2.2
17.7	27.2	22.0	2.9
11.8	22.0	16.7	3.0
11.9	23.8	17.3	3.5
29.3	43.7	35.7	4.4
12.8	27.3	21.0	4.3
10.5	17.2	13.9	1.9
17.3	27.3	21.8	3.1
12.2	24.8	16.0	3.5
12.8	20.1	16.8	2.2
19.5	31.1	24.2	3.9
13.0	47.3	18.9	9.7
12.3	21.5	18.2	3.1
22.0	60.6	41.9	11.2
15.4	25.6	21.2	3.4

Bucco-pharyngeal apparatus of the Hypsibius type, without the ventral lamina, and with forked apophyses for stylet muscles (Fig. 6). Peribuccal lamellae absent. Teeth in the oral cavity armature absent or not visible under PCM. Pharyngeal bulb with apophyses and with two granular macroplacoids (both, without constrictions). Macroplacoid length sequence 2<1. Microplacoid and septulum absent. Figures 6-7. Hypsibius cf. scabropygus Cuenot , 1929: 6 bucco-pharyngeal apparatus (dorso-ventral projection, ventral placoids in the insert) 7 claws IV (arrow indicates a small cuticular bar near the posterior claw). (Both PCM). Claws of the Hypsibius type, internal claws much smaller and of a different shape than the external claws (Fig. 7). All main branches with large accessory points. Smooth, indistinct areoles under claws usually visible only on posterior claws IV. Cuticular bars under claws I-III absent but a small bar is present near the posterior claw IV (Fig. 7, arrow). Eggs. Unknown. Remarks . Hypsibius scabropygus has been recorded from many localities, mostly in the Holarctic ( McInnes 1994 ). In general, our specimens correspond to the original description by Cuenot (1929 , 1932 ) and later descriptions by Marcus (1930) (= Hypsibius callimerus spec. nov.), and by Ramazzotti and Maucci (1983) . However, importantly, none of the above mentioned descriptions reported a bar between anterior and posterior claws IV, which is present in all our specimens. Given the bar is small, it is possible that it was overlooked by Cuenot and later authors. If, however, Hypsibius scabropygus does not have the bar, then our specimens should probably be classified as a new species. Thus, until Hypsibius scabropygus is redescribed, our Latvian and Estonian records should be regarded as Hypsibius cf. scabropygus. As there is a possibility of our specimens belonging to a new species, we provide standard morphometrics (Table 1) and photographs (Figs 1-7).