Richtersius sp.
Creators: name: Vecchi, Matteo
name: Godziek, Jakub
name: Kristensen, Reinhardt M.
name: Piemontese, Lucia
name: Calhim, Sara
name: Stec, Daniel
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Tardigrada
Eutardigrada
Parachela
Macrobiotidae
Richtersius

description: Richtersius sp. [Ca1 MK214326]
Richtersius sp. 6 – Stec et al. 2020b.
Description
No information on this species morphology is available.
Reproductive mode
Gonochoric (Stec et al. 2020b).
DNA sequences
– 18S: MK211387 (Stec et al. 2020b)
– 28S: MK211385 (Stec et al. 2020b)
– COI: MK214326 -8 (Stec et al. 2020b)
– ITS2: MK211382 -3 (Stec et al. 2020b)
Distribution
Genna Silana, Sardegna, Italy (40°09′04″ N, 9°30′23″ E; 1047 m a.s.l.). Moss (sample IT. 317 in Stec et al. 2020b).
Richtersius sp. [Ca2 KT778685]
Richtersius Mongolia – Guidetti et al. 2016.
Richtersius sp. 2 – Stec et al. 2020b.
Description
In the newborns, many small cuticular pores (diameter 1–2 µm) with regular margins are present. Claw common tract shorter than half of the total claw length. The buccal tube walls are extremely enlarged after the stylet support insertions (Guidetti et al. 2016). Additional morphometric data for this species are presented in Guidetti et al. (2016).
Reproductive mode
Gonochoric (Guidetti et al. 2016).
DNA sequences
– 18S: KT778708 -10 (Guidetti et al. 2016)
– 28S: KT778699 -701 (Guidetti et al. 2016)
– COI: KT778683 -9 (Guidetti et al. 2016)
Distribution
Mongolia (46°47.311′ N, 101°57.848′ E; 1790 m a.s.l.). Moss (samples C2592 and C 2595 in Guidetti et al. 2016).
Richtersius sp. [Ca3 GU237485]
Description
No information on this species morphology is available.
Reproductive mode
Unknown.
DNA sequences
– COI: GU237485, GU339056 (unpublished).
Distribution
Unpublished, probably Asia.
Dichotomous key of the genus Richtersius
Here we provide a taxonomic key which include six nominal species that are currently recognized within the genus.
1. Egg with processes having proximal portion in shape of wide domes while distal portion elongated and slender; crown of thickenings distributed around the bases of the egg processes ....................... ........................................................................................... Richtersius mazepi Kiosya & Stec, 2022
– Egg different ..................................................................................................................................... 2
2. Egg bare diameter ≥170 µm; in newborns, pore density ≥ 60 pores/ 2500 µm 2 ................................ ............................................................................................... Richtersius coronifer (Richters, 1903)
– Egg bare diameter <170 µm; in newborns, pore density <60 pores/ 2500 µm 2 .............................. 3
3. In newborns, pore density ≥ 20 pore /2500 µm 2 ........... Richtersius ziemowiti Kayastha et al., 2020
– In newborns, pore density <20 pore / 2500 µm 2 ............................................................................... 4
4. In newborns, pore density ≥ 9 pore / 2500 µm 2 ........................................ Richtersius nicolai sp. nov.
– In newborns, pore density ≤ 7 pore / 2500 µm 2 ................................................................................. 5
5. Macroplacoid 1 pt> 13 .................................................... Richtersius tertius Pogwizd & Stec, 2022
– Macroplacoid 1 pt <13 ......................................................................... Richtersius ingemari sp. nov.
description: Published as part of Vecchi, Matteo, Godziek, Jakub, Kristensen, Reinhardt M., Piemontese, Lucia, Calhim, Sara & Stec, Daniel, 2025, Taxonomic reanalysis of the genus Richtersius (Tardigrada; Eutardigrada), with description of two new species from Italy and Sweden, pp. 155-188 in European Journal of Taxonomy 981 on pages 181-182, DOI: 10.5852/ejt.2025.981.2823, http://zenodo.org/record/15023722