Photodocumentation
Photodocumentation - defined and purpose 
What and how to document
Microscopy issues
Image manipulation
Photodocumentation - defined and purpose
The purpose of photoducumentation, in the context of descriptions of protists, is to produce an uninterpreted record of an organism that documents that characterustics that make the organism distinctive.
The identities of plants and animals are ultimately tied to a real specimen using sets of rules and conventions that are established by the Codes of Nomenclature. The identity of bacterial species are locked into cultures and DNA sequences. This is called 'typification' and places something objective and uninterpreted as the foundation for an identity. Unfortunately, many protists are soft bodies and do not culture or preserve well. Over 200,000 species have been described and comprehensive catalogues of sequences are many years off. This creates a problem as to how to best leave an objective record of what a name refers to.
In a series of studies of flagellates from topical sandy beaches (Larsen, J. & Patterson, D. J. 1990. Some flagellates (Protista) from tropical marine sediments. Journal of Natural History, 24: 801-937) Larsen and Patterson acknowledged the tradition of documenting protists by light and electron microscopy and proposed to adapt a ruling in the Botanical Code that allows for the use of images to document taxa. In essence, the images act as a surrogate 'voucher' specimen.
The approach required that organisms are documented using uninterpreted means (photography or video microscopy). This is to overcome problems in which the artist's rendition of an organism may be fanciful (right) or inaccurate (below).
Euglena acus, after Saville-Kent 1880-182. Manual of the Infusoria, Bogue, London.
The image on the left is an electron micrograph of Paratetramitus jugosus, and clearly illustrates the four basal bodies characteristic of many flagellated members of this group. The image on the right is an interpretative drawing (Kinetid structuire, diagrammatic representation) based on the ultrastructural study and suggests that the organism has just two basal bodies. After Enzien, M., McJKhann, H. I and Margulis, L. 1989. Ecology and life history of an amoebomastigote, Paratetramitus jugosus, from a microbial mat: new evidence for multiple fission. Biological Bulletin, 177: 110-129.
A particular reason for wanting to have documentation is that sequence information is being added to databases such as Genbank without any evidence as to the identity of the source of the organism. 'Trees' based on comparisons of sequence information have been assembled in which misidentified organisms have been included. Other problems arise when sources of nucleic acids are contaminated cultures. The result is evolutionary models that are inaccurate because they have been misinformed. We therefore advocate the development of 'vouchers' using uninterpreted photographic records, and that such vouchers be deposited in a stable and publicly visible location.
(example to be added of the 'opalines' that in reality were oomycetes)
This document deals primarily with documentation by light microscopy.
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