Why not just take a picture?
Noumea sulphurea, Noumea closei, Noumea haliclona and scanning electron microscope images of their radula.
Photos by B Rudman. Scanning electron microscope photos by G Avern.
These Sea Slugs from northern Tasmania are almost impossible to tell apart from the photographs alone. Australian Museum scientist Bill Rudman only realised they were actually three different species after he examined an internal feature the radula (a tooth-covered tongue found in most molluscs which isused like a rasp or file to remove food from hard sufaces).
The Palespotted Podge, Pseudogramma polyacantha is a very common reef fish that lives deep inside coral. It is never seen or photographed by divers and can only be recorded from areas where intensive collecting techniques have been used. Photo: J Williams
A photographic record and even a sight record can be very useful. It can greatly enhance the value of a specimen or object and form an important part of the data collected. A photograph can capture details such as the bright colour of most seaslugs which is lost once the specimen is preserved. Photographs can also record a specimen or object in its natural habitat or cultural setting, and record movements too fast for the human eye. Macro photography, scanning electron microscope (SEM) images and x-rays also provide information often not visible to the naked eye without damaging the specimen.
Without an actual specimen or object, however, problems can arise if the validity of a record is ever questioned. A photograph often doesn't display important characteristics or any internal features that may be required to confirm the identification of the specimen or help in a revised identification based on new data. There are also many species which stay hidden and can only be found using intensive collecting techniques. These could never be photographed.
Copyright © Australian Museum 2004