Accepted: 29 July 2019
First Online: 11 August 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors that require approval by the ethical committee. In fact according to present regulation studies on invertebrates, such as <i>Eisenia andrei</i> do not need ethical authorization.