New tardigrade records for the Baltic states with a description of Minibiotus formosus sp. n. (Eutardigrada, Macrobiotidae)

Abstract

In sixteen moss, lichen and mixed (moss/lichen) samples, collected from Estonia, Latvia and Lithuania, 291 specimens, 48 simplexes, including one exuvium with 6 eggs, and 8 free-laid eggs of eutardigrades were found. In total, 17 species, together with one new to science, were identified (all are new records for the Baltic states): Astatumen bartosi, Diphascon (Adropion) prorsirostre, D. (Diphascon) bullatum, D. (D.) pingue pingue, D. (D.) recamieri, D. (D.) rugosum, Hypsibius convergens, H. dujardini, H. cf. scabropygus, Isohypsibius ronsisvallei, I. sattleri, Macrobiotus harmsworthi harmsworthi, M. hufelandi hufelandi, Milnesium asiaticum, Milnesium tardigradum tardigradum, Minibiotus formosus sp. n. and Paramacrobiotus richtersi. The new species is most similar to Minibiotus gumersindoi, but differs from it mainly by the presence of two types of cuticular pores, the absence of a triangular or pentagonal arrangement of pores above a single large pore on legs, the presence of granulation on all legs and a different macroplacoid length sequence. In this paper we also provide photographs and morphometrics of H. cf. scabropygus.

Milnesium berladnicorum sp. n. (Eutardigrada, Apochela, Milnesiidae), a new species of water bear from Romania

“…However, based on modern literature, all these records should be considered as dubious and need verification ( Michalczyk et al 2012a , 2012b ). This is now even more necessary due to the discovery in 2014 of two other Milnesium species in Romania ( Ciobanu et al 2014 ): a) Milnesium asiaticum Tumanov, 2006, previously known only from three localities in Kyrgyzstan ( Tumanov 2006 ), Spitsbergen ( Kaczmarek et al 2012b ) and Estonia ( Zawierucha et al 2014 ); and b) Milnesium granulatum (Ramazzotti, 1962) previously known only from three localities in Chile, Italy and USA ( McInnes 1994 ; Bartels et al 2014 ) (see map above).…”

“…Since the genus was recently re-described ( Michalczyk et al 2012a , 2012b ) new records and species have been reported from various localities (e.g. Kaczmarek et al 2012a ; Meyer et al 2013 ; Zawierucha et al 2014 ; Ciobanu et al 2014 ). Taking into consideration that some morphological characters were omitted in older records of Milnesium specimens, all such records should be verified ( Michalczyk et al 2012a , 2012b ).…”

Redescription of Milnesium alpigenum Ehrenberg, 1853 (Tardigrada: Apochela) and a description of Milnesium inceptum sp. nov., a tardigrade laboratory model

“…antarcticumTumanov, 2006, only recorded from the Antarctic(Smykla et al 2012), by the maximal length of the buccal tube (≤68 µm in M. alpigenum vs >68 µm in M. antarcticum), a smaller buccal tube standard width (8.6-23.6 µm in M. alpigenum vs 25.9-31.8 µm in M. antarcticum), and by a statistically lower pt of the stylet support insertion point (61.1-70.3, on average 64.9 in M. alpigenum vs 70.0-73.7, on average 71.5 in M. antarcticum; t 38 =16.708, p<0.001).• M. argentinumRoszkowska, Ostrowska & Kaczmarek, 2015, reported from Argentina, by the appearance of cuticle (faint pseudopores visible only with a high quality PCM on the caudal part of the dorsal cuticle in M. alpigenum vs well-visible pseudopores in M. argentinum on the entire dorsum with a standard PCM), and by the lower pt of the primary branches IV (46.9-63.2 in M. alpigenum vs 28.4-36.4 in M. argentinum). • M. asiaticumTumanov, 2006, recorded from Kirghizstan (type locality), China(Beasley & Miller 2007),Estonia(Zawierucha et al 2014) and the Svalbard archipelago (Kaczmarek et al 2012), by a statistically lower pt of primary branches III (39.7-51.7, on average 45.8 in M. alpigenum vs 51.5-58.3, on average 55.3 in M. asiaticum; t 36 =15.385, p<0.001) and by a lower pt of primary branches IV (46.9-63.2 in M. alpigenum vs 63.9-76.0 in M. asiaticum). • M. barbadosense Meyer & Hinton, 2012, only reported from the type locality in Barbados, by a lower pt of the stylet support insertion point (61.1-70.3 in M. alpigenum vs 71.6-82.1 in M. barbadosense) and by a higher pt of the primary branches IV (46.9-63.2 in M. alpigenum vs 28.4-42.2 in M. barbadosense).…”

Terrestrial Tardigrada (Water Bears) of the Słowiński National Park (Northern Poland)

“…Species with wide Holarctic distribution [38][39][40]. The original description is uncertain and the species needs a modern redescription [53]. Species new for the Polish fauna.…”