Pseudechiniscus ehrenbergi, Roszkowska & Grobys & Bartylak & Gawlak & Kmita & Kepel & Kepel & Parnikoza & Kaczmarek, 2020

Roszkowska, Milena, Grobys, Daria, Bartylak, Tomasz, Gawlak, Magdalena, Kmita, Han- Na, Kepel, Andrzej, Kepel, Marta, Parnikoza, Ivan & Kaczmarek, Łukasz, 2020, Integrative description of five Pseudechiniscus species (Heterotardigrada Echiniscidae: the suillus-facettalis complex), Zootaxa 4763 (4), pp. 451-484: 454-461

publication ID

http://doi.org/ 10.11646/zootaxa.4763.4.1

publication LSID

lsid:zoobank.org:pub:urn:lsid:zoobank.org:pub:0DE45665-F3A9-474B-B438-1022FABB6BD1

DOI

http://doi.org/10.5281/zenodo.3804847

persistent identifier

http://treatment.plazi.org/id/554F87D9-0772-F746-00C1-FE7D552DCCF1

treatment provided by

Carolina

scientific name

Pseudechiniscus ehrenbergi
status

sp. nov.

1. Pseudechiniscus ehrenbergi   sp. nov. Roszkowska, Grobys, Bartylak & Kaczmarek

( Tables 1–2 View TABLE 1 View TABLE 2 , Figs 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Pseudechiniscus   sp. 1 ( Grobys et al. 2020)

Pseudechiniscus aff. suillus   [Ca6] MONGOLIA C 2595-V06 ( Cesari et al. 2020)

Material examined: 35 animals (holotype (female) and 34 paratypes (31 females, 3 males )) mounted on microscope slides in Hoyer’s medium, 30 animals prepared for SEM and 5 prepared for barcoding.

Description

Animals (measurements and statistics in Tables 1 View TABLE 1 and 2 View TABLE 2 )

Females. Body ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 ) yellow-orange in living specimens (transparent after mounting on slides), black eyes present after mounting on slides. Apart from the head appendages (cirri interni and externi and spherical cephalic papillae [secondary clavae]), only lateral cirrus A present (with finger-like [primary] clavae near the base) ( Fig. 2B View FIGURE 2 ). Cephalic papillae smaller than clavae.

Dorsal plates with small hemispherical granules/upper ends of cuticular pillars (dots in LM) 0.3–0.8 μm in di- ameter, densely (spaces between granules 0.2–1.1 μm) and uniformly distributed and not joined by striae ( Figs 2A View FIGURE 2 , 3 View FIGURE 3 A–B). Granules/upper ends of cuticular pillars slightly larger in the centre of the plates.

Dorsal plates typical for the genus Pseudechiniscus   (cephalic plate (cp), neck plate (np) scapular plate (scp), median plates (m1, m2, m3), paired segmental plates I and II (s1, s2), pseudosegmental plate (psp), and the caudal plate (cap), see also Dorsal and ventral plates and sculpture in Grobys et al. (2020)) well developed. The cp with W-shaped pattern divided into five parts. The scp divided by a transversal fold, forming a long narrow stripe in posterior part of the plate. This narrow stripe often divided by three longitudinal folds resulting in four parts/subplates ( Fig. 2A View FIGURE 2 ). Entire scp divided by median longitudinal fold into two parts ( Fig. 2 View FIGURE 2 A–B, empty arrow). Lateral portions of the scp appear detached from the dorsal plate, forming small plate-like structures separated from the scp by a thin bright stripe ( Fig. 3A View FIGURE 3 , indented arrowhead). Plates m1 and m2 divided in two portions by transverse fold, plate m3 undivided ( Fig. 2 View FIGURE 2 A–B, filled indented arrowheads). Laterally to the median plates, lateral intersegmental plates (lip) present. On the plates s1 and s2 darker stripes (folds in SEM) visible ( Fig. 2 View FIGURE 2 A–B, filled arrows). The psp divided by a longitudinal fold. Posterior margin of psp straight, i.e. without projections, teeth or spines ( Fig. 2 View FIGURE 2 A–B, empty indented arrowheads). The cap concave with two Y-shaped bifurcated ridges ( Fig. 2B View FIGURE 2 , filled arrowhead). Ventral cuticle with tiny granulation (formed by dense granules/upper ends of cuticular pillars, 0.1–0.4 μm) forming a unique pattern ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D). Ventral patches of granulation present (granulation 0.5–0.6 μm in diameter, spaces between granules 0.5–1.0 μm) with configuration PG:I-II-III-IV-VI-VIII g ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D). The female gonopore with the typical six-petal rosette. ( Fig. 2 View FIGURE 2 C–D, asterisks).

The outer cuticle on legs I–III with round patches of granulation (with larger granules but more sparse in the centre and smaller and denser in peripheral parts), on legs IV with uniform wide stripes of granulation (slightly larger in the centre of these stripes) ( Fig. 3 View FIGURE 3 C–D). Triangular spine on leg I absent, instead a small papilla-like structure present, but very hardly visible under LM ( Figs 2D View FIGURE 2 , 3C View FIGURE 3 filled arrowheads). Dentate collar on leg IV absent. A finger-like papillae on leg IV present ( Fig. 3D View FIGURE 3 , filled arrow). External claws of all legs smooth, internal with spurs directed downwards, identical on legs I–IV ( Fig. 3E View FIGURE 3 ).

Males ( Figs 1 View FIGURE 1 , 4 View FIGURE 4 ). Body slenderer than in females. Dorsal plates and body appendages arranged identically like in females. Head appendages clearly longer than in females (compare Tables 1 View TABLE 1 and 2 View TABLE 2 ). Dorsal granules/upper ends of cuticular pillars larger than in females (0.4–1.3 μm in diameter), densely (spaces between granules 0.5–1.3 μm) and uniformly distributed, not joined by striae ( Fig. 4 View FIGURE 4 A–C). Ventral pattern (granules/upper ends of cuticular pil- lars, 0.1–0.4 μm) of different shape than in females ( Figs 1 View FIGURE 1 , 4 View FIGURE 4 D–E). Patches of granulation with configuration PG: I-II-III-IV-VI-VIII a (granules/upper ends of cuticular pillars, 0.4–0.7 μm) ( Figs 1 View FIGURE 1 , 4 View FIGURE 4 D–E). The gonopore round and without six-petal rosette and with more distinct PG in anterior and lateral parts ( Fig. 4E View FIGURE 4 ). The leg sculpture similar to females but with larger granulation ( Fig. 4F View FIGURE 4 ). Triangular spine on leg I absent, instead a small papilla-like structure present, but very hardly visible under LM ( Fig. 4F View FIGURE 4 , filled arrowhead).

Juveniles. Unknown.

Larvae. Unknown.

PG

PG

PG

PG

PG

PG

PG

PG

. suillus ( Ehrenberg, 1853)   Pse. ehrenbergi   sp. nov. Pse. ehrenbergi   sp. nov. Pse. dastychi   sp. nov. female female male female Pse. angelusalas   sp. nov. Pse. lacyformis   sp. nov. Pse. indistinctus   sp. nov. female female female

DNA sequences

We obtained good quality sequences for the applied molecular markers:

- COI sequence (GenBank: MN528470 View Materials ), 686 bp long;

- ITS-2 sequence (GenBank: MN537866 View Materials ), 405 bp long.

Etymology.

We dedicate this species to the distinguished German zoologist Christian Gottfried Ehrenberg, who described Pse. suillus   , the first species in the genus Pseudechiniscus   .

Type locality.

45°53’10’’N, 10°50’11’’E, 140 m asl: Italy, Trentino Province, Riva del Garda, on the way to the Bastion, moss from dead wood, 07.07.2016, coll. Daria Grobys and Hanna Kmita.

Type depositories.

Holotype: slide IT40/7 and 25 paratypes (slides: IT40/*, where the asterisk can be substituted by any of the following numbers: 3, 7, 9, 3/S, 4/S, 5/S, 6/S, 7/S) are deposited at the Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland; 16 paratypes (slide IT40/10) are deposited at the collection of Binda and Pilato, Museum of the Department of Animal Biology ‘Marcello La Greca’, University of Catania, Italy.

Morphological differential diagnosis*

*only measurements of adult females are used in differential diagnosis

Pseudechiniscus ehrenbergi   sp. nov. differs specifically from:

1. Pse. angelusalas   sp. nov., known only from Madagascar (the present study), by: a small papilla-like structure on leg I present, different ventral pattern ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D for Pse. ehrenbergi   sp. nov. vs Figs 1 View FIGURE 1 , 7B View FIGURE 7 for Pse. angelusalas   sp. nov.), different position of PG VIII (PG VIII placed around gonopore in Pse. ehrenbergi   sp. nov. vs PG VIII placed only above gonopore in Pse. angelusalas   sp. nov.), lower sp of cephalic papillae (12.8–17.1 in Pse. ehrenbergi   sp. nov. vs 18.3–20.8 in Pse. angelusalas   sp. nov.), lower sp of clavae (17.7–20.6 in Pse. ehrenbergi   sp. nov. vs 22.4–25.7 in Pse. angelusalas   sp. nov.), lower sp of cirrus A (95.1–112.6 in Pse. ehrenbergi   sp. nov. vs 129.2–152.2 in Pse. angelusalas   sp. nov.), lower cirrus A /body length ratio (14–17% in Pse. suillus   vs 19–22% in Pse. angelusalas   sp. nov.), higher cirri interni / externi length ratio (72–85% in Pse. ehrenbergi   sp. nov. vs 66–71% in Pse. angelusalas   sp. nov.), longer papillae on leg IV (2.8–3.3 μm in Pse. ehrenbergi   sp. nov. vs 2.0–2.4 μm in Pse. angelusalas   sp. nov.) and longer claws (see Tables 1 View TABLE 1 and 4).

2. Pse. beasleyi, known only from China ( Li et al. 2007), by: scp not divided in anterior part (scp divided into four parts in Pse. beasleyi), smaller granules of dorsal sculpture (0.3–0.8 μm in Pse. ehrenbergi   sp. nov. vs up to 1.6 μm in Pse. beasleyi), shorter cirri interni and externi (7.1–8.6 and 9.0–11.7 μm respectively in Pse. ehrenbergi   sp. nov. vs 10.4–15.7 and 13.1–18.3 μm respectively in Pse. beasleyi), different claw lengths arrangement (shortest claws II and III, and longest claws IV in Pse. ehrenbergi   sp. nov. vs shortest claws I and II, and longest claws III and IV in Pse. beasleyi) and shorter claws (see Table 1 View TABLE 1 in this paper and Table 2 View TABLE 2 in Li et al. 2007).

3. Pse. chengi, known only from China ( Xue et al. 2017), by: a small papilla-like structure on leg I present, plates m1 and m2 divided in two portions by transverse fold (unndivided in Pse. chengi), shorter claws I–III and lower sp of claws I–II (see Table 1 View TABLE 1 herein and Table 2 View TABLE 2 in Xue et al. 2017).

4. Pse. clavatus   , known only from Spain ( Mihelčič 1955), by: different shape of clavae (finger-like in Pse. ehrenbergi   sp. nov. vs club-shaped in Pse. clavatus   ) and normally developed cephalic papillae (reduced in Pse. clavatus   ).

5. Pse. dastychi   sp. nov., known only from Antarctica ( Dastych 1984 and present study), by: a small papilla-like structure on leg I present, different ventral pattern ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D for Pse. ehrenbergi   sp. nov. vs Figs 1 View FIGURE 1 , 5 View FIGURE 5 C–D for Pse. dastychi   sp. nov.), different ventral PG configuration (PG:I-II-III-IV-VI-VIII g in Pse. ehrenbergi   sp. nov. vs PG:I-II-III-IV-V-VI-VII-VIII a in Pse. dastychi   sp. nov.), dorsal granules not joined by striae, narrower scp (20.3–26.6 μm in Pse. ehrenbergi   sp. nov. vs 27.5–33.0 μm in Pse. dastychi   sp. nov.), shorter cirri interni (7.1–8.6 μm in Pse. ehrenbergi   sp. nov. vs 10.4–12.7 μm in Pse. dastychi   sp. nov.), shorter cirri externi (9.0–11.7 μm [sp=39.6–49.6] in Pse. ehrenbergi   sp. nov. vs 15.9–19.1 μm [sp=54.7–61.4] in Pse. dastychi   sp. nov.), shorter cirri A (21.6–26.8 μm [sp=95.1–112.6] in Pse. ehrenbergi   sp. nov. vs 40.0–45.0 μm [sp=135.2–149.1] in Pse. dastychi   sp. nov.), lower cirrus A /body length ratio (14–17% in Pse. ehrenbergi   sp. nov. vs 22–26% in Pse. dastychi   sp. nov.), higher cirri interni/externi length ratio (72–85% in Pse. ehrenbergi   sp. nov. vs 62–69% in Pse. dastychi   sp. nov.) and shorter claws (see Tables 1 View TABLE 1 and 3).

6. Pse. facettalis   , known from distant localities throughout the world ( McInnes 1994). Based on present study, an inaccurate description of this species makes it impossible to differentiate this taxon from Pse. ehrenbergi   sp. nov.. See also Morphological differential diagnosis of Pse. suillus   and Discussion in the paper Grobys et al. (2020).

7. Pse. indistinctus   sp. nov., known only from Norway (present study), by: a small papilla-like structure on leg I present, different ventral pattern ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D for Pse. ehrenbergi   sp. nov. vs Figs 1 View FIGURE 1 , 13 View FIGURE 13 C–D for Pse. indistinctus   sp. nov.), different ventral PG configuration (PG:I-II-III-IV-VI-VIII g in Pse. ehrenbergi   sp. nov. vs PG: I-II-III-IV-V-VI-VIII a in Pse. indistinctus   sp. nov.), granules on cap similar in size to other dorsal plates (granules visibly larger on cap in comparison with other dorsal plates in Pse. indistinctus   sp. nov.), lower sp of cirri externi (39.6–49.6 in Pse. ehrenbergi   sp. nov. vs 54.3–59.3 in Pse. indistinctus   sp. nov.), shorter cirri A (21.6–26.8 μm [sp=95.1–112.6] in Pse. ehrenbergi   sp. nov. vs 27.6–34.2 μm [sp=123.0–144.9] in Pse. indistinctus   sp. nov.), lower cirrus A /body length ratio (14–17% in Pse. ehrenbergi   sp. nov. vs 18–22% in Pse. indistinctus   sp. nov.), higher cirri interni/externi length ratio (72–85% in Pse. ehrenbergi   sp. nov. vs 62–70% in Pse. indistinctus   sp. nov.) and lower spur/branch length ratio of all claws (17–24% in Pse. ehrenbergi   sp. nov. vs 28–34% in Pse. indistinctus   sp. nov.).

8. Pse. juanitae   , known from Austria, Brazil (type locality), Italy and Galapagos Islands ( McInnes 1994). Based on present study, an inaccurate description of this species makes it impossible to differentiate this taxon from Pse. ehrenbergi   sp. nov.. See also Morphological differential diagnosis of Pse. suillus   and Discussion in the paper Grobys et al. (2020).

9. Pse. lacyformis   sp. nov., known only from Norway (the present study), by: a small papilla-like structure on leg I present, different ventral pattern ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D for Pse. ehrenbergi   sp. nov. vs Figs 1 View FIGURE 1 , 10B View FIGURE 10 for Pse. lacyformis   sp. nov.), different position of PG VIII (PG VIII placed around gonopore in Pse. ehrenbergi   sp. nov. vs PG VIII placed above gonopore in Pse. lacyformis   sp. nov.), shorter cirri interni (7.1–8.6 μm [sp=32.3–37.4] in Pse. suillus   vs 10.6–14.0 μm [sp=48.4–53.9] in Pse. lacyformis   sp. nov.), shorter cirri externi (9.0–11.7 μm [sp=39.6–49.6] in Pse. suillus   vs 14.1–19.4 μm [sp=66.5–77.8] in Pse. lacyformis   sp. nov.), shorter clavae (4.0–4.7 μm [sp=17.7– 20.6] in Pse. ehrenbergi   sp. nov. vs 5.1–6.4 μm [sp=23.4–26.8] in Pse. lacyformis   sp. nov.), lower sp of cirrus A (95.1–112.6 in Pse. ehrenbergi   sp. nov. vs 114.1–142.5 in Pse. lacyformis   sp. nov.) and lower sp of papillae on leg IV (11.3–13.7 in Pse. ehrenbergi   sp. nov. vs 14.7–17.2 in Pse. lacyformis   sp. nov.).

10. Pse. megacephalus   , known only from Austria (type locality) and Turkey ( McInnes 1994), by: different shape of cephalic papillae (spherical in Pse. ehrenbergi   sp. nov. vs mushroom-like in Pse. megacephalus   ), absence of papilliform projection between external buccal cirri and cirri A.

11. Pse. suillus   , known only from Italy and Portugal ( Grobys et al. 2020), by: different ventral pattern ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D for Pse. ehrenbergi   sp. nov. vs Figs 1 View FIGURE 1 herein and 4C–D in Grobys et al. (2020) for Pse. suillus   ), well developed ventral patches of granulation, shorter cirri interni (7.1–8.6 μm [sp=32.3–37.4] in Pse. ehrenbergi   sp. nov. vs 8.7–11.1 μm [sp=44.0–49.6] in Pse. suillus   ), lower sp of cephalic papillae (12.8–17.1 in Pse. ehrenbergi   sp. nov. vs 19.1–24.3 in Pse. suillus   ), shorter cirri externi (9.0–11.7 μm [sp=39.6–49.6] in Pse. ehrenbergi   sp. nov. vs 12.0–16.8 μm [sp= 62.1–75.0] in Pse. suillus   ) lower sp of clavae (17.7–20.6 in Pse. ehrenbergi   sp. nov. vs 20.9–26.8 in Pse. suillus   ), shorter cirrus A (21.6–26.8 μm [sp=95.1–112.6] in Pse. ehrenbergi   sp. nov. vs 28.4–34.4 μm [sp=134.9–156.9] in Pse. suillus   ) and lower sp of papillae on leg IV (11.3–13.7 in Pse. ehrenbergi   sp. nov. vs 14.7–18.4 in Pse. suillus   ).

12. Pse. xiai   , known only from China ( Wang et al. 2018), by: different ventral pattern ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 C–D for Pse. ehrenbergi   sp. nov. vs Figs 1B, F View FIGURE 1 and 2E View FIGURE 2 in Wang et al. 2018 for Pse. xiai   ) and higher cirrus A /body length ratio (17–21% in Pse. ehrenbergi   sp. nov. vs 13–16% in Pse. xiai   ).

Genotypic differential diagnosis

The ranges of genetic distances between Pse. ehrenbergi   sp. nov. and species of the genus Pseudechiniscus   , for which DNA sequences are available in GenBank, are as follows:

COI: 0.4–29.3% (22.4% on average), with the most similar being Pse. aff. suillus   ( MK804906 View Materials , Cesari et al. 2020) and the least similar being Pseudechiniscus   sp. ( KJ857008 View Materials , Velasco-Castrillón et. al. 2015 (described in Gen- Bank as Echiniscus   sp.); for more details see Discussion section in Grobys et al. 2020).

ITS-2: 7.7–35.5% (25.1% on average), with the most similar being Pse. dastychi   sp. nov. ( MN537865 View Materials , present study) and the least similar being Pse. lacyformis   sp. nov. ( MN537868 View Materials , present study).

Kingdom

Animalia

Phylum

Tardigrada

Class

Heterotardigrada

Order

Echiniscoidea

Family

Echiniscidae

Genus

Pseudechiniscus

Loc

Pseudechiniscus ehrenbergi

Roszkowska, Milena, Grobys, Daria, Bartylak, Tomasz, Gawlak, Magdalena, Kmita, Han- Na, Kepel, Andrzej, Kepel, Marta, Parnikoza, Ivan & Kaczmarek, Łukasz 2020
2020
Loc

Pseudechiniscus

Grobys et al. 2020
Loc

Pseudechiniscus aff. suillus

Cesari et al. 2020