So, what help is available?
The following are easily available, cheap and when used together will enable anyone to get started identifying Cladocera. See also our hints and tips page (coming soon) .....
A Key to the British Species of Freshwater Cladocera, with Notes on their Ecology
D.J. Scourfield & J.P. Harding
Third edition, 1966 (reprinted 1994), 61pp. ISBN 978-0900386-01-5 Freshwater Biological Association ... £10
As stated above this rather old key from the FBA is reprinted from the last 1966 edition and is still available from the FBA website. There is also link to their website on our links page.
There are a number of problems with this key, especially for newcomers to the Cladocera, the main ones being:
- Some species are included which later work has shown either not to occur in the British Isles or to be synonyms.
- A number of the species names have been revised since 1966 as taxonomy has progressed. (But see note on British list below)
- The illustrations are rather small, the printing does not aid their clarity and in fact the original 1941 edition highlit the main characteristics, a feature removed in the second edition.
- The reference list is of course woefully out of date by now.
A key to the freshwater cladocerans of France and the neighbouring countries of western Europe, 'Crustacés cladocères'
Société Linnéenne de Lyon Tome 53 (1984) n°3-4 ... Free (This key has recently been giving problems but is now working again.)
This is a very visual key which is just as well for it is written entirely in French. However non French speakers should not be put off at all. In fact for the rare occasions when the text is not immediately obvious the Google translation service will turn the key-questions into English very well indeed. The author also notes in the abstract that it was written for 'non-specialists'. Fortunately the Micscape website has made the key freely downloadable in pdf form at:
Microscopy UK, Micscape magazine article library
..... and do also explore the rest of the Micscape site via our links page.
Although this publication is also a quarter of a century or more in age it suffers from slightly fewer of the problems of taxonomic revision than Scourfield & Harding. It does cover some non-British species but includes the vast majority of our own fauna. Where it does score is that the scanning for the pdf download is of sufficient quality to give the illustrations great clarity and so the key features are easily compared with your specimen. This is especially true if using the Amoros key on a laptop next to your microscope which facilitates enlargement at will.
An Updated Key ? What is the best approach?
The FBA has informed us that they are keen to see a new key written and indeed one was started a few years ago but the project eventually came to a halt. So until a new and up to date key is produced the best approach would seem to be to use both of the two keys outlined above in conjunction with an up to date species list.
The updated species list is now available from the Cladocera Interest Group, just go to the downloads
link on the left. In April 2013 one of our members Dave Bentley produced a document which allows users
to annotate a copy of Amoros in line with the new checklist for Britain & Ireland. This makes it easy
to update species names, points out the species in Amoros that do not occur in Britain & Ireland and
shows where in Amoros the few unlisted British species would key out. More information on the download
Additionally you can also go to our downloads page and save a copy of the NINA posters for 71 British species and compare the information / illustrations as confirmation of your identification.