@Tarsius : I hope you forgive me for saying this, but with your posts it is sometimes difficult to tell if you are being sarcastic or not. Assuming you are not, in this case at least, yes you are right, both species - not subspecies-, the Amazonian manatee (Trichechus inunguis) and the West Indian manatee (Trichechus manatus) are relatively easy to tell apart, although maybe not as easy as African and Asian elephants to everyone. Amazonian manatees are smaller and darker, they also often have white patches. As far as I know, Amazonian manatees are not kept anywhere outside of South America (maybe not even outside of Brazil).
Hopefully Nürnberg can continue its long tradition of keeping and breeding their manatees successfully, now that they have this very nice new home