RE: What do var, cf. etc mean?

June 8, 2001
From: Nishina Chikako

Hello Dear Dr.Rudman,

Thank you very much for your kind explanation. I guess I could understand the part about 'cf' and 'var'. but I have more question on sp. It's a bit difficult for me.

Does sp. means 'one of' or 'a kind of'? For example does 'Atys sp.' mean a kind of 'Atys? Do you use it when you are sure that it's a kind of Atys but it's not A.cylindrica, A. naucum, A. semistriata or any other species of Atys you know?

When you said: "It does not necessarily mean that the species does not have a name. It just means that the person using 'Tritonia sp.' does not know if the species has a name".
I got confused with this. Do you mean 'the species might have a name but you don't know it?' And you mention about a 'local name' which a local diver might use or some like a Japanese name decided in the academy of Japan?

And another question: In the Forum you have numbered these unnamed species sp1, sp2 etc. Is it possible that for example Chromodoris sp. 1. in your Forum is called Chromodoris sp. 2 or 'Chromodoris A' in another Forum or country?

Sincerely yours

Nishina, C., 2001 (Jun 8) RE: What do var, cf. etc mean? . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Chikako,
I think the answer to all your questions is yes.

The only universal and unambiguous name for a species is its scientific name. That is why we have so many rules and an International Committee to supervise naming of species and to sort out problems as they arise.

However it is not always practical to formally name or identify every apparent species we find in our day to day work. For example when we get material to identify for ecological studies and surveys the ecologists are usually more interested in how many different kinds of animals are present and are not willing to wait for the few taxonmists available to either identify all the animals present or if necessary give them new names. So we have these conventions Atys sp. 1, Atys cf. naucum, etc. They do not have universal meaning and only apply to the immediate job, report, or book. For example there is a species which Terry Gosliner has called in his South African book Glossodoris sp. 4 which in the Forum I have called Glossodoris sp. 1. As long as future workers note where the 'name' is used there is no confusion. And yes calling something Glossodoris sp. 1 does not necessarily mean that the species does not have a species name, it could just mean that I don't know it.

Concerning 'Common names' and 'Local names'. I could be wrong but I think in Japan you have a formal system of giving animals a Japanese language common name. For example when Hamatani described Cyerce kikutarobabai he also gave it the Japanese name Kanoko-urokoumiushi. I think this is unique to Japan. In other countries 'common names' or 'local language names' have either existed for hundreds of years in very small geographic regions, or have been made up quite recently either in local communities, or have been invented by authors or publishers for popular books. In Sydney local divers call Pteraeolidia ianthina the Blue Dragon because they think it looks like the heraldic dragons on Chinese temples, but I don't know of people anywhere else calling it that. I guess the Spanish Dancer for Hexabranchus is one of the few common names which are really common.

I realise this is probably difficult and complicated to follow in English, so if it still puzzles you please don't hesitate to ask again.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Jun 8). Comment on RE: What do var, cf. etc mean? by Nishina Chikako. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


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