Echiniscus testudo ( Doyère, 1840 )

Gąsiorek, Piotr & Vončina, Katarzyna, 2023, Atlas of the Echiniscidae (Heterotardigrada) of the World-part I: West Palaearctic Echiniscus species, Zootaxa 5344 (1), pp. 1-72 : 55

19. Echiniscus testudo ( Doyère, 1840)

Figures 34–36

Synonyms

Echiniscus bellermanni C.A.S. Schultze, 1840 : C.A.S. Schultze (1861)

Echiniscus biunguis C.A.S. Schultze, 1861 : Cuénot (1932)

Echiniscus filamentosus Plate, 1888 : Gąsiorek et al. (2017)

Echiniscus glaber Bartoš, 1937 : Gąsiorek et al. (2017)

Echiniscus inermis Richters, 1902 : Cuénot (1932)

Echiniscus peruvianus Binda & Pilato, 1994 : Gąsiorek et al. (2021d)

Emydium testudo Doyère, 1840

Echiniscus trifilis Rahm, 1925 : Cuénot (1932)

Locus typicus: France, Paris.

New type locality: 48°53’10’’N, 2°19’54’’E, 70 m asl: France, Paris, Montmartre Cemetery.

Etymology: From Latin testūdō = tortoise, probably stressing the presence of dorsal armour. A noun in apposition.

Shortened description. Medium-sized to large (ca. 280–360 μm). Body appendage configuration A-(B)-C- Dd- E, with frequent asymmetries. All lateral appendages cirrous, whereas Dd –spiniform ( Fig. 34A ). Dorsal plate sculpturing of the testudo type, with small, numerous and randomly distributed pseudopores ( Fig. 35 ). Dentate collar IV with usually less than 10 short and irregular teeth. Claws elongated and strongly heteronych, with minute, needle-like primary spurs closely positioned to claw bases ( Fig. 36 ). Larvae with reduced chaetotaxy, their body appendage formula: A-Dd- E ( Fig. 34B ). Pseudopores poorly developed, so sometimes the surface of plates may seem to be smooth in LM.

Phylogenetic position: Echiniscus testudo is an isolated evolutionary lineage, currently with no revealed close relatives (Fig 1–2, see Remarks).

Remarks: The species is cosmopolitan ( McInnes 1994; Jørgensen et al. 2007, 2013; Gąsiorek et al. 2017, 2019c, 2021d), probably as a result of anthropogenically-mediated dispersal. The closest relatives of E. testudo likely are E. ehrenbergi Dastych & Kristensen, 1995 and another dark-pigmented species from the Himalayas (termed “ E. cf. testudo ” in Jørgensen et al. 2007), based on an identical chaetotaxy and similar dorsal plate sculpturing.

Figures

FIGURE 34. Echiniscus testudo from France (PCM; modified from Gąsiorek et al. 2017): A—female (neotype), B—larva. Scale bars = 50 μm.

FIGURE 35. Echiniscus testudo from France—dorsal plate sculpturing (PCM; modified from Gąsiorek et al. 2017): A— scapular plate, B—median body portion. Scale bars = 10 μm.

FIGURE 36. Echiniscus testudo from France (claws; modified from Gąsiorek et al. 2017): A—claws II (PCM), B—claws II (SEM). Arrowheads indicate minuscule primary spurs. Scale bars in μm.