Tardigrades of North Carolina
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View PDFEchiniscidae Members: 3 NC Records

Pseudechiniscus suillus group (Ehrenberg, 1853) - No Common Name


Dorsal and Ventral, PC Grobys et al. 2020 Specimen from Mt. Rosa, Alps
Taxonomy
Class: HeterotardigradaOrder: Echiniscoidea Family: Echiniscidae Checklist Number: 2110.0
Taxonomic Comments: Pseudechiniscus was subdivided into two subgenera by Gasiorek et al. 2021. Pseudechiniscus (Pseudechinsicus) contains species with pseudohemispherical cephallic papillae as opposed to dactyloid papillae. The description for Pseudechiniscus (Pseudechiniscus) suillus s.s. was amended by Grobys et al. 2020.
Species Notes: Terrestrial. This species has been reported from all around the world, but it is a pseudocryptic complex. Pseudechiniscus suillus s.s. is likely to be localized around Sweden and Switzerland. Thus, we have changed these records to P. suillus group.
Identification
Online resources:Online Photographs: Google, GBIF                                                                                 
Species Description: For Pseudechiniscus suillus s.s.:
Females: Body (Fig. 4) yellow-orange in living specimens (transparent after mounting), eyes black after mounting. Apart from the head appendages [cirri interni and externi and spherical or slightly elongated cephalic papillae (secondary clava)], only lateral cirrus A present [with finger-like clava near the base (primary clava)] (Fig. 4A, B). Cephalic papillae smaller than primary clava. Dorsal plates with small hemispherical granules/ upper ends of cuticular pillars (dots in LM) 0.3–0.7 μm in diameter, densely (spaces between granules 0.3– 1.1 μm) and uniformly distributed and not joined by striae (Fig. 5B). Granules/upper ends of cuticular pillars are slightly larger in the centre of the plates. Dorsal plates typical for the genus Pseudechiniscus [single 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 ‘Dorsal and ventral plates and sculpture’ above] well developed. The cp facetted (with W-shaped pattern) divided into five parts (Fig. 4A, empty arrowhead). The scp divided by a transversal fold, which forms a long, narrow stripe in the posterior part of the plate. This narrow stripe is often divided by three longitudinal folds, resulting in four plate parts/subplates (Fig. 4A, B). Besides, the entire scp is divided by a median longitudinal fold into two parts (Fig. 4A, B, empty arrow). Additionally, lateral portions of the scp appear to be detached from the dorsal plate, forming small plate-like structures separated from the scp by a thin, bright stripe (Fig. 4A). Plates m1 and m2 are divided in two portions by a transverse fold; plate m3 is undivided (Fig. 4A, B, filled indented arrowheads). Laterally to the median plates, lateral intersegmental plates (lip) are present. On plates s1 and s2, darker stripes (folds in SEM) are also visible (Fig. 4A, filled arrow). The psp is divided by a longitudinal fold. Posterior margin of psp is straight, i.e. without projecting teeth or spines (Fig. 4A, B, empty indented arrowheads). The cap is concave with two Y-shaped bifurcated ridges (Fig. 4A, B, filled arrowhead). Ventral cuticle with tiny granulation (formed by dense granules/upper ends of cuticular pillars, 0.2–0.4 μm) forming a unique pattern (Figs 3, 4C, D, 5C). Ventral patches of granulation present, but most of them poorly marked and visible sometimes as a smooth areas almost without granulation (if granulation is present it is 0.3–0.5 μm in diameter, spaces between granules 0.2–0.3 μm), with configuration PG:I-II-III-IV-VI-VIIIg (Figs 3, 4C, D). The female gonopore with the typical six-petal rosette (Fig. 4C, D, asterisks). The outer cuticle on legs I–III has round patches of granulation (with larger granules but sparser in the centre and smaller and denser in peripheral parts); on legs IV, uniform wide stripes of granulation (slightly larger in the centre of these stripes) (Fig. 5D–F). Triangular spine on leg I absent, instead a small papilla-like structure present, but very hardly visible under LM (Fig. 5A). Dentate collar on leg IV absent. A finger-like papilla on leg IV present (Fig. 5E, filled arrow). External claws of all legs smooth, internal with spurs directed downwards (Fig. 5F).
-Grobys et al. 2020
Body Length: 142-186 microns.
Key Characters: Ventral sculpture and morphometrics, DNA.
Key Character Images
ID Requirements: Identifiable only by close inspection of key characters or by DNA analysis.
Distribution in North Carolina
Distribution:
County Map: Clicking on a county returns the records for the species in that county.
Dates:
 High Mountains (HM) ≥ 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

Click on graph to enlarge
Habitats and Life History
Habitats: Moss and liverworts.
Abundance: Common in Nelson's Roan Mt. inventory.
Diet: Herbivorous.
Reproduction: Smooth eggs deposited in exuvium.
Observation Methods: PC, DIC, SEM.
Wikipedia

 Photo Gallery for Pseudechiniscus suillus group - No common name

Photos: 3

Recorded by: Nelson on 1971-10-15
Mitchell Co.
Comment: Dorsal and Ventral, PC Grobys et al. 2020 Specimen from Mt. Rosa, Alps		Recorded by: Nelson on 1971-10-15
Mitchell Co.
Comment: Dorsal and ventral SEM, specimen from Mt. Rosa, Alps, Grobys et al. 2020
Recorded by: Nelson on 1971-10-15
Mitchell Co.
Comment: Fig. 5, Grobys et al. 2020, Specimen from Mt. Rosa, Alps