Species of sap sucking slug?

Found at 10 feet in Bequia, St Vincent and the Grenadines. An interesting type of sap sucker that I haven't seen here before. Identification help please!

Possibly Chelidonura berolina

Am I right in my research that they are now classified as Chelidonura africana?

According to WORMS C, berolina is an accepted species - http://www.marinespecies.org/aphia.php?p=taxdetails&id=532602

but Rudman believes C. berolina is 'is almost certainly a synonym' of C. africana - http://www.seaslugforum.net/find/chelafri

Take your pick!

As far as we know Chelidonura species eat flatworms rather than green algae like the true sap-suckers.

As far as we know Chelidonura species eat flatworms rather than green algae like the true sap-suckers.

I'm curious about this term "sap-sucker" being applied to marine creatures. I didn't realize algaes had sap. Any idea why they have that name?

Thanks,

Gina

You're right, algae don't have sap. I suspect the name is just a catchy alliteration & over-simplification of what's really happening. "Sap-suckers" are members of the opisthobranch order Sacoglossa and feed by sucking out the internal contents of algal cells.

For more info about sacoglossans check out the wikipedia entry - http://en.wikipedia.org/wiki/Sacoglossa - or browse through some of the posts on the Sea Slug Forum - www.seaslugforum.net -

Thanks for the links Leslie