Don't toss your worms, forward them!

By George Brown, Embrapa Forestry/Federal University of Paraná (BRAZil)

Approximately one quarter of the world's animals live in the soil (Anthony et al. 2023), and yet samples taken in even well studied regions can yield new species, particularly in the tropics and subtropics. This is true even for well-known taxa such as earthworms for which around 5,750 species have been discovered, although it estimated that there are over 30 thousand species of earthworms. This can lead to a deficit in biological information that is worsened by inadequate preservation of soil fauna specimens collected worldwide.

Periscolex brachycystis, a native earthworm of Mexico, with a tissue sample taken from the posterior part of the body and placed in the Eppendorf vial, for posterior DNA extraction and molecular analysis (Photo: Carlos Fragoso). 

In a paper co-authored by earthworm taxonomists Marie Bartz, Samuel James, Csaba Csuzdi, Daniel Marchán, Carlos Fragoso, Thembeka Nxele, and Chih-Han Chang, recently published in the journal Biodiversity, we make an appeal to researchers who work with or collect soil fauna to adequately preserve and forward their samples to institutions that can store this material over the long-term. The article includes a list of specialists and institutions worldwide that can receive earthworm specimens, aiming to preserve them for future research, thus avoiding the loss of global genetic heritage. It also provides step-by-step instructions on how to sacrifice, preserve and forward the specimens.

A new species of earthworm in the genus Glossoscolex, in the Natural History Museum of the Federal University of Paraná in Curitiba, Brazil (Photo: George Brown). 

Importantly, after carrying out the often-arduous field work needed to collect soil fauna specimens, one must also undertake the equally arduous subsequent work of cleaning, sorting, cataloging, and finally, preserving and maintaining these samples for future studies. Unfortunately, we have seen many situations where this latter process, a routine in museums and zoological collections, was not adequately conducted. This occurs especially in institutions with limited infrastructure or support for preserving fauna samples. Consequently, many samples often collected in biologically rich locations can dry out or rot, and are subsequently discarded and/or lost, as there is no infrastructure or space available to accommodate the material and maintain it with due curatorial care.

One of the moving cabinets of the earthworm collection (Fritz Müller Oligochaete Collection - COFM) at Embrapa Forestry in Colombo, Brazil. (Photo: George Brown).

Although focused on earthworms, this appeal can be equally applied to many other taxa of soil or epigeic invertebrates collected using Pitfall traps, Winkler, Berlese, or Tulgren extractors, or by hand sorting of monoliths with the Tropical Soil Biology and Fertility (TSBF) method. However, for non-Annelid taxa different sample preparation techniques may be required, so if you have specimens of other taxa that you wish to forward, please contact regional or state zoological museums, to get advice on the fixing, processing and shipping of your specimens (contact information for some countries can be found in the manuscript). If you have specimens collected using any of these methods, and you believe that you cannot adequately preserve and maintain them over the long-term, please forward them as a donation to appropriate institutions. Besides guaranteeing their conservation, this additionally provides specimens for future studies (especially of taxonomic, genetic and biogeographic nature) and helps avoid the loss of important biological information!

Finally, please remember to adhere to the Nagoya protocol for signatory countries, which includes obligations on the protection, use and sharing of benefits derived from biodiversity. Furthermore, remember to follow the laws and regulations concerning the shipment of biological specimens within-country or to other countries. If specimens are to be shipped or donated to other countries/institutions, various other official scientific or bureaucratic documentation may be necessary. Please certify that all the necessary permits and documents are in order before mailing your specimens.

We thank you in advance for your efforts and contributions towards the long-term preservation of our world’s rich soil biological heritage!