Notaspids from Colombia

Dear Phanor,
Thanks for the interesting photos of the two pleurobranchs. Like many Caribbean opisthobranchs, there is still some problems in identifying species from your region. The biggest problem being that the original descriptions were not very detailed and there were no accompanying illustrations. Later workers may have compounded the problem by misidentifying these earlier names. There is no easy way to be sure but I think these photos are of Pleurobranchus areolatus Moerch, 1863. I have reached that conclusion, not because there are any characters positively identifying it with Moerch's original description but because chracters found in two other species from the Caribbean are absent from Moerch's description of P. areolatus. In particular, the Mediterranean Pleurobranchus testudinarius is recorded f rom the Caribbean but has large pointed tubercles. The other distinctive species I have seen photos of from the Caribbean is the animal in your second message which is characterised by the white triangular makes on some tubercles.

So I can't be sure that this is P. areolatus, but I am not sure we are ever going to be sure just what Moerch's species was.
Best wishes,
Bill Rudman.