Minibiotus pseudostellarus, Roszkowska, Milena, Stec, Daniel, Ciobanu, Daniel Adrian & Kaczmarek, Łukasz, 2016

Roszkowska, Milena, Stec, Daniel, Ciobanu, Daniel Adrian & Kaczmarek, Łukasz, 2016, Tardigrades from Nahuel Huapi National Park (Argentina, South America) with descriptions of two new Macrobiotidae species, Zootaxa 4105 (3), pp. 243-260: 254-257

publication ID

http://doi.org/10.11646/zootaxa.4105.3.2

publication LSID

lsid:zoobank.org:pub:B0FEF435-9EBF-4C91-AFDB-6F616848FD44

persistent identifier

http://treatment.plazi.org/id/03E10656-FE4E-6A49-E4FB-FF5CE3CDFCE5

treatment provided by

Plazi

scientific name

Minibiotus pseudostellarus
status

sp. nov.

Minibiotus pseudostellarus View Treatment   sp. nov.

( Table 3, Figs 12–21 View FIGURES 12 – 14 View FIGURES 15 – 17 View FIGURES 18 – 21 )

http://www.tardigrada.net/register/0023.htm

Localities and number of specimens. VI (1), XIV (1), XXI (7 and 1 exuvium), XXV (5 and 1 exuvium)

Material examined. Holotype (slide: 2306 / 3), 13 paratypes (slides: 1437 / 1, 1462 / 7, 1472 / 2 and 2306 / 2), two exuviae (slides: 1437 / 1 and 2306 / 3).

Description (measurements and statistics in Table 3). Animals: Body length 241–320 µm ( Fig. 12 View FIGURES 12 – 14 ), white/ transparent after fixation. Eyes present in all specimens before and after fixation in Hoyer’s medium. Cuticle smooth with pores distributed randomly and not forming any specific design ( Fig. 14 View FIGURES 12 – 14 ). Generally two types of pores are present over the entire cuticle: round-shaped (0.3–0.9 µm in diameter) and in the shape of ‘pseudo-stars’ (i.e. not fully developed ‘stars’ but with 3–4 irregular ‘arms’ and poorly visible incisions) (0.6–2.5 µm distance from the farthest points of arms) ( Fig. 14 View FIGURES 12 – 14 ). Moreover, large star-shaped pores (with 5–6 ‘arms’) are present on legs (a single pore on leg I –III and two pores above legs IV ( Figs 18–21 View FIGURES 18 – 21 ). Pores around mouth absent.

Bucco-pharyngeal apparatus of the Minibiotus   type, with the ventral lamina and ten peribuccal papulae. Oral cavity armature absent or not visible under PCM. Pharyngeal bulb oval, with triangular apophyses (very near to first macroplacoid and ca. same size), three macroplacoids and small microplacoid. Macroplacoid length sequence 1 ≤ 2 <3 ( Fig. 13 View FIGURES 12 – 14 ).

Claws short and robust with obvious accessory points ( Figs 15–17 View FIGURES 15 – 17 ). Fine granulation only present on legs IV ( Figs 16, 17 View FIGURES 15 – 17 ). Cuticular bars under claws I –III present. Other cuticular thickenings on legs absent. Lunules under claws with smooth margins ( Fig. 16 View FIGURES 15 – 17 ).

Eggs: Not found.

Etymology. The new species is named after the characteristic pores on the cuticle—simulating (pseudo) stars (stellarum).

Type locality. 41 ° 12 ’S, 71 ° 51 ’W, ca. 1,200 m asl: Río Negro, Nahuel Huapi National Park, Bariloche, at the foot of the Tronador volcano, Garganta del Diablo waterfall, moss from rock, 17.01. 2012, coll. Dawid Diduszko.

Type depositories. Holotype, 12 paratypes and two exuviae are deposited at the Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61–614 Poznań ( Poland) and one paratype (slide 1472 / 2) is deposited at the Department of Entomology Institute of Zoology Jagiellonian University, Gronostajowa 9, 30–387, Kraków, Poland.

Differential diagnosis. By the presence of star-like pores in the cuticle (on the legs), the new species is most similar to Min. constellatus   Michalczyk & Kaczmarek 2003 b, Min. eichhorni   Michalczyk & Kaczmarek 2004, Min. sidereus   Pilato et al. 2003 and Min. vinciguerrae   Binda & Pilato 1992, but it differs from all of them by the presence of ‘pseudo-stars’ instead of fully developed stars on dorsal and ventral cuticle. Additionally, new species differs specifically from:

Minibiotus constellatus   , only recorded from Peru ( Michalczyk & Kaczmarek 2003 b), by absence of pores around the mouth, different arrangement of pores on the dorsal side of the body (randomly arranged pores in Min. pseudostellarus   sp. nov. vs. two rows of pores along the main axis of the body in Min. constellatus   ), the presence of eyes, absence of granulation on legs I –III (granulation present on all legs in Min. constellatus   ), different macroplacoid sequence (1 ≤ 2 <3 in Min. pseudostellarus   sp. nov. vs. 3 <2 <1 in Min. constellatus   ), longer third macroplacoid (2.4 – 3.6 µm in Min. pseudostellarus   sp. nov. vs. 1.4 – 1.9 µm in Min. constellatus   ), slightly longer macroplacoid row with higher pt (8.7 – 11.0 µm [35.5–38.9] in Min. pseudostellarus   sp. nov. vs. 6.7 – 8.6 µm [25.0–35.4] in Min. constellatus   ).

Minibiotus eichhorni   , only recorded from Peru ( Michalczyk & Kaczmarek 2004), by different arrangement of pores on the dorsal side of the body (randomly arranged pores in Min. pseudostellarus   sp. nov. vs. pores arranged in six transverse bands in Min. eichhorni   ), absence of granulation on legs I –III (granulation present on all legs in Min. eichhorni   ), shorter external primary and secondary branches of claws III (5.6 – 7.1 µm and 4.4 – 5.5 µm respectively in Min. pseudostellarus   sp. nov. vs. 7.6 – 11.4 µm and 5.7 – 8.6 µm in Min. eichhorni   ), higher pt of the buccal tube external width ([10.2–11.6] in Min. pseudostellarus   sp. nov. vs. [6.9–9.7] in Min. eichhorni   ), a slightly higher pt of the second macroplacoid length ([9.3–11.3] in Min. pseudostellarus   sp. nov. vs. [6.9–9.2] in Min. eichhorni   ), smaller pt of the external primary branches of claws II ([21.7–25.5] in Min. pseudostellarus   sp. nov. vs. [26.9–33.3] in Min. eichhorni   ), smaller pt of the external primary branches of claws III ([22.7–26.8] in Min. pseudostellarus   sp. nov. vs. [29.4–33.3] in Min. eichhorni   ), and smaller pt of anterior primary and secondary branches of claws IV ([26.6–31.7] and [19.1–22.4] in Min. pseudostellarus   sp. nov. vs. [34.6–41.7] and [23.1–27.8] in Min. eichhorni   , respectively).

Minibiotus sidereus   , only recorded from Ecuador ( Pilato et al. 2003), by stylet supports inserted in a more posterior position ([65.6–68.8 in Min. pseudostellarus   sp. nov. vs. [58.6–58.9] in Min. sidereus   ), a slightly higher pt of the second macroplacoid length ([9.3–11.3] in Min. pseudostellarus   sp. nov. vs. [7.9–9.1] in Min. sidereus   ), longer macroplacoid row with higher pt (8.7–11.0 µm [35.5–38.9] in Min. pseudostellarus   sp. nov. vs. 5.7–7.9 µm [26.6–29.9] in Min. sidereus   ) and longer placoid row with higher pt (10.4–13.0 µm [42.2–46.2] in Min. pseudostellarus   sp. nov. vs. 6.4–9.6 µm [29.9–36.4] in Min. sidereus   ).

Minibiotus vinciguerrae   , only recorded from Antarctica ( Binda & Pilato 1992), by the lack of oral cavity armature, absence of granulation on legs I –III, short and robust claws (long and slender in Min. vinciguerrae   ), different macroplacoid sequence (1 ≤ 2 <3 in Min. pseudostellarus   sp. nov. vs. 2 <3 <1 in Min. vinciguerrae   ), smaller body size (230–326 µm in Min. pseudostellarus   sp. nov. vs. 380–520 µm in Min. vinciguerrae   ), shorter buccal tube (23.5–29.3 µm in Min. pseudostellarus   sp. nov. vs. 35.1 µm in Min. vinciguerrae   (in specimen 520 µm in length)), lower width of the buccal tube (2.5–3.3 µm in Min. pseudostellarus   sp. nov. vs. 3.6 µm in Min. vinciguerrae   (in specimen 520 µm in length)), smaller first and second macroplacoid (2.2–3.2 µm [8.9–10.9] and 2.3–3.3 µm respectively in Min. pseudostellarus   sp. nov. vs. 4.4 µm [12.4] and 3.6 µm respectively in Min. vinciguerrae   (in specimen 520 µm in length)), smaller microplacoid (1.1–1.5 µm in Min. pseudostellarus   sp. nov. vs. 1.9 µm in Min. vinciguerrae   (in specimen 520 in length)), shorter macroplacoid and placoid rows (8.7–11.0 and 10.4–13.0 µm respectively in Min. pseudostellarus   sp. nov. vs. 13.1 and 15.39 µm in Min. vinciguerrae   (in specimen 520 µm in length)) and smaller length and pt values of the external primary branches of claws II, III, IV (5.7–7.3 µm [21.7–25.5], 5.6–7.1 µm [22.7–26.8] and 6.7–8.9 µm [26.6–31.7] respectively in Min. pseudostellarus   sp. nov. vs. (12.34 µm [35.1], 12.63 µm [35.9] and 14.6 µm [41.6] respectively in Min. vinciguerrae   (in specimen 520 µm in length)).

TABLE 3. Measurements [in µm] and pt values of selected morphological structures of Minibiotus pseudostellarus sp. nov. 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).

  14        
  14        
  14        
  14        
  14        
  13        
  14        
  14        
  14        
  14        
  14        
  14        
  10        
  10        
  12        
  10        
PCM

Polish Collection of Microorganisms