Images used in Algaevision

Image Types

About two thirds of the 2,300 images are colour photographs of living algae in which every attempt has been made to focus on features (eg cell or colony morphology, chloroplasts, or other cytological features) required for identification. These photomicrographs are intended to be an identification aid and have been taken using various light microscopy techniques, such as brightfield illumination, differential interference contrast and phase contrast.

Some of Peter York's images from the 2005 version of AlgaeVision were produced using digital image auto-montaging software designed by the Synoptics Company (developed in collaboration with the Natural History Museum) to produce in-focus photomicrographs from an electronically processed series of optical slices. Many of the new images taken by Chris Carter used similar software called Helicon Focus. However, sometimes several images are presented of the same species to demonstrate morphological variation. Occasionally a single specimen is photographed at different focal points or in more than one plane. As for desmids and other three-dimensional algae, a single image will not include all features required for identification. Several such images are sometimes arranged as a montage and may include close views of empty cells since wall ornamentation is frequently more clearly visible in cells lacking contents. 

The database includes images of reproductive structures, which are especially relevant in those genera (eg Vaucheria, Spirogyra, Oedogonium) where species identification is dependent on features associated with reproduction. Some scanning electron microscope (SEM) photographs are included to assist in the interpretation of structures visible under the light microscope, particularly in the case of some dinoflagellates and the euglenoid genus Trachelomonas. There are also images of algal habitats, conspicuous macroscopic growths and discolouration of water bodies caused by the presence of large quantities of planktonic microalgae ('plankton blooms').


A feature of the new version is the presence of anaglyphs (see Sphaeroplea soleiroli, Hydrodictyon reticulatum and Chara vulgaris var. papillata) which are three-dimensional images requiring special glasses to view (the left lens is red, the right lens cyan). These glasses are widely available. 

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith