Hi! I am happy I found this site. I've been collecting shells for a few years now and I am trying to catalogue my shells. I am no expert but I'm learning fast through research and passionate collecting. I have lots of questions especially in identifying the shells and I will appreciate any help. Please
What is the difference between a cyprae zebra and a cervinetta? I have three big ones they all look similar.
How about a cypraea leviathan from just a cypraea carneola. I have several huge "carneolas" (60-70+mm) and I'm thinking they are leviathans because I find only small carneolas on the internet.
These two for now.
Chris

Hi Chris,
Welcome to the site. Both pairs of species you mentioned have to be separated on fairly fine points when working from the shell alone.

C. zebra, as compared to C. cervinetta, is relatively more plump and more cylindrical. Which is to say that C. cervinetta is relatively more elongate (has a higher length-to-width ratio) and relatively more depressed (dorso-ventrally flattened). The apertures of both species widen anteriorly, but more so in C. cervinetta. In C. zebra the anterior aperture is about twice as wide as the posterior aperture; in C. cernivetta about three times as wide. In C. zebra many of the spots low on the lateral margins, where the dorsum meets the base of the shell, are ocellated, that is the white spots have dark centers so they look like "rings". In C. cervinetta all or most of the spots on the lateral margins are solid white, though I have seen specimens with a few lightly ocellated spots mixed in. Using these criteria I would estimate that 90% of specimens can be identified with certainty quite easily, but there may be 10% that are more ambiguous. Of course if you have reliable locality data this will help since C. zebra is Atlantic/Caribbean while C. cervinetta is Pacific.

The carneola/leviathan question offers us less to work with. Locality data won't help since C. carneola is found everywhere that C. leviathan is found. The mantles of the two species are quite distinct, however that doesn't help when we have only the shell to work with. C. leviathan grows considerably larger than C. carneola. C. carneola seldom exceeds 50 mm and almost never exceeds 60 mm. C. leviathan often exceeds 70 mm and sometimes exceeds 100 mm. When C. leviathan reach a large size the lateral margins begin to develop raised smooth tubercles (bumps). Therefore a shell larger than 60 mm with tuberculate margins is almost surely C. leviathan. However, a small, young C. leviathan which has not yet developed such tubercles cannot reliably be separated from C. carneola by shell characteristics alone.

Hi! That is the information I've been looking for!!! Thank you so much!!!! Definitely big big help! I'll study those shells immediately. The "carneolas" given to me are all more than 50mm. Yes, one of them has nodes on the margin. All came from Negros, Philippines.

I have another one, please. I have lots of mappas in my collection. I've been researching on the net but can't find an answer. I'm not even sure how to group them because some have pink base, some offwhite, some have brownish/purplish base. Some have this dark brown dorsum and others tan. Are all mappas found in the philippines just the typical mappa mappa? HOw is a mappa rosea identified?

Chris  

Wow. I just found out one shell labeled cervinetta is actually zebra. It was easy identifying them with your help. Just by the apertures alone and the spots. Thanks much!
Chris

Btw, how about a carneola bouteti?  

Chris

I just grouped my carneolas from the leviathans. The carneolas are from 72-75mm. Big sizes but no bumps on the margins. The leviathans from 74-80mm they all have those bumps on the margin with callousing.
One mystery to me - one, size 62mm, is calloused and with typical bumps on the margin. Good gloss and aside from a thin growth line, no dorsal problems. Not a carneola, right? Because of the marginal nodules.  

Chris