Echiniscus arctomys Ehrenberg, 1853 sensu

Kaczmarek, Łukasz, Michalczyk, Łukasz & Mcinnes, Sandra J., 2015, Annotated zoogeography of non-marine Tardigrada. Part II: South America, Zootaxa 3923 (1), pp. 1-107 : 10

10. Echiniscus arctomys Ehrenberg, 1853 sensu lato [T]

Terra typica: Switzerland (Europe)

Argentina:

• 41°59′S, 71°34′W; 300 m asl: Rio Negro Province, El Bolsón, Valley of Rio Azul, mosses on tree ( Myrceugenia exupca ) in the Myrceugenia exupca - Nothofagus dombeyi marsh forest. Iharos (1963)

• 41°59′S, 71°31′W; 360 m asl: Rio Negro Province, El Bolsón, foot of Piltriquitron Mt., mosses on wet cliff of promontory, partly on soil and mosses on dry ledge (2 samples). Iharos (1963)

• 41°59′S, 71°31′W; 460 m asl: Negro Province, El Bolsón, foot of Piltriquitron Mt., live and decayed mosses on and under stones on cliff. Iharos (1963)

Brazil:

• 22°58′S, 43°15′W; 450 m asl: Rio de Janeiro State, neighbourhood of Rio de Janeiro, Tijuca National Park, mosses and algae. Rahm (1931, 1932)

Record numbers: Argentina: 3, Brazil: 1; total: 4.

Remarks: Currently E. arctomys is considered a species complex nested within a larger group ( arctomys group - sensu Ramazzotti & Maucci 1983), defined via a single pair of body cirri but with variable cuticle sculpture and other morphological traits. The loss of body cirri is a potential homoplasy while diverse cuticular sculpture and other traits require a number of evolutionary steps, so it is very likely that the arctomys group (sensu Ramazzotti & Maucci 1983) is polyphyletic, but this has to be verified via integrated morphological and molecular techniques.

The nominal species of the complex was originally described from Europe ( Ehrenberg 1853), so this South American record requires confirmation.