On Noumea norba, N.purpurea, N.varians etc

Dear Maki,

Your message arrived just as I was finishing a series of pages on a group of species which are very similar in colour to Noumea purpurea. In 1986 I thought N. purpurea and N. norba were the same species, but not N. varians. If you look at my message about those pages, it should answer your question.

The reason we consider some of these species to be different is nothing to do with slight colour differences (an extra spot here or a coloured line there), it is based on quite major differences in their internal anatomy, such as the shape of their reproductive system and radular teeth. After the anatomy has told us that there are different species, we have to find some way to identify the living animals without having to cut everyone of them up! That is why we have to look very carefully at their colour patterns to find differences, however slight, which are unique to a particular species.

You mention that Noumea purpurea wasn't in the Species List. The list only includes those species that I have a page for in the Forum. It is not a list of all the world's species. Now that I have included a page for Noumea purpurea it is in the list.

If you have any other questions or photos you want identified I am happy for you to send them.

Best wishes,
Bill Rudman.