Dear Paola,
Perhaps someone is keeping a list and can give us a 'guesstimate'
Cheers,
Bill Rudman

Dear Amanda,
Your project sounds very interesting and I look forward to hearing of your results. I don't know of any life history / life cycle studies on Oxynoe viridis but I am pretty sure it has planktotrophic eggs so will be difficult to breed in aquarium conditions unless you have facilities to culture phytoplankton-feeding veliger larvae. Concerning feeding, have a look at the Sacoglossan Feeding and Sacoglossan Biology pages for some background information. There are references and messages there discussing the food of Australian species.

There is also a lot of information on feeding scattered through various messages so it would pay to use the search facility on the Forum to search for food and feeding. Another way would be to look through the sacoglossan species in the Species List. There are many photos of species on their probable food algae.
Best wishes,
Bill Rudman

Dear Victor,
The short answer is I know of no reason why they should store old teeth. Perhaps its to do with the way they feed. Certainly in molluscs which treat their teeth relatively roughly - grazers and scrapers for example, the worn teeth are broken off just through the nature of the feeding behaviour of the animal. However sacoglossans feed by piercing the cell wall of their algal food. Perhaps the way they feed means the functional teeth need to be strongly attached to the underlying ribbon, so strongly attached in fact that once the tooth is blunt and of no further it can't be easily broken off during the feeding movements of the sacoglossan. A sac would be a place for the useless teeth to accumulate out of 'harm's way'.

Just a flight of fancy on my behalf. Hopefully one of our sacoglossan experts can give us a better explanation.
Bill Rudman.