Imaging Soil Mesofauna. The Land in Between

Abstract

This chapter will try to make some generalisations on current approaches to the imaging of small specimens. By that, we mean those with sizes lying typically between that of microphotography and that of macrophotography. These constraints do not necessarily mean a requirement for taxon-specific techniques. Rather, mainstream imaging procedures can be successfully used, although it is advisable to consider certain characteristics of the taxa in question. A case, or rather ‘bookcase’, study (i.e. different taxonomic groups) depicting our laboratory’s procedures will act as a basis for discussing several issues. Assemblages of the largest specimens can be pictured, though rarely, with SLR cameras fitted with a good macro lens. However, mesofauna are usually imaged under the stereomicroscope or by transmitted light microscopy. Preserved specimens are typically mounted on slides and imaged at low power under optical or scanning electron microscope, and details are captured at higher magnifications. Surfaces, and superficial features, are targeted more often than internal structures, and optical techniques are much more common for contrast improvement than chemical stains. The main drive should be directed at ensuring a good scientific usability of the images. Thus, compromises will be needed where feature visibility, enhancement, and fidelity conflict with aesthetic qualities.The wide spectrum of soil mesofauna means that a variety of handling and preparation procedures, as well as several observation and imaging techniques, are applied even within a group. Thus, the proposed ”bookcase” study will have several tiers at times, where techniques differ for specific groups.