Using earthworms as model organisms in the laboratory: Recommendations for experimental implementations

Earthworms are used in an increasing number of microcosm experiments that investigate their behaviour and biology or that consider earthworms an environmental factor that influences soil properties and biological interactions. However, there exists no standardized protocol for performing comparable studies. After giving a short overview of the different experimental approaches using earthworms as model organisms, the present paper provides recommendations for the planning and execution of earthworm experiments that help in achieving comparable results. The recommendations, summarized in a workflow diagram, pertain to the acquisition, treatment and description of earthworms for experimentation, the description and preparation of test soils and the criteria that should be met for valid experimental results.