A simple technique for digital imaging of live and preserved small fish specimens
The present methodological paper presents a simple technique for digital imaging of small fish specimens using conventional flatbed scanners. Preparing such scanners with a plasticine pool enables fish specimens to be scanned under submerged conditions in water, ethanol or glycerine, depending on whether they are alive or preserved. This technique relies on a quickly prepared, less complicated setup than in photography and provides the opportunity to gain digital images of small fish in the laboratory as well as – with some restrictions – in the field. Lateral scans can be easily made of live specimens after narcotisation or of preserved fish. The scanning method yielded high-quality images of near- live colours of live fish and of preserved coloration. Images had good contrast, sharpness and illumination, minimal or no shadows and high resolutions when scanned on high-quality scanners. Depth of field in images was good for fishes of less than 20 cm length and less than 2 cm body width. The method is recommended for applications where digital images are required for body shape analyses, such as geometric morphometric approaches, for qualitative or quantitative analyses of coloration patterns, for fish (re-)identification, and as a basis for illustrations or for publication in electronic sources or print media.