A peculiarity of the human being is never to be satisfied. Over the years this has also been true for marine aquariums and we have gone from breeding fish, which populate the seas on the other side of the world, to much more unusual animals. Nowadays it is more and more common to find tanks dedicated to jellyfish, octopus, squid, cuttlefish and much more. I recently had a video where in a tank it was not an octopus or a cuttlefish that was raised, but a distant relative: the Nautilus. At first glance I thought: “wow”!Wonderful! A fantastic, almost epic animal. I thought about it a lot and developed my idea. Before explaining it to you, however, let's first introduce who is this "little" animal that fascinated me so much.
The Nautilus (from the Greek “nautilos”, navigator) is the only representative of a once very diversified group: the nautiloids. It is part of the phylum mollusca, precisely to the class of cephalopods, to which octopus, cuttlefish and squid also belong. A typical feature of the nautilus, which allows us to identify it and distinguish it from other cephalopods, is the presence of an external shell that protects the animal's body. This shell has a spiral winding and is very different from the shells of gastropods and bivalves in that it has internal chambers containing gas, which allows it to swim. The animal occupies only the outermost chamber of the envelope, has a number of tentacles ranging from 60 to 90 and secretes specific secretions for the capture of prey. The Nautilus is the only cephalopod to have two pairs of gills, and has very simple eyes that are not comparable to those of vertebrates. This fascinating mollusk is capable of reaching depths of about 400m, which makes it an abyssal animal, and which we almost never find on the surface. Its characteristics different from those of the animals we are used to observe make it extremely fascinating and mysterious, arousing in hobby enthusiasts the desire to raise one.
It is precisely these characteristics that led me to further reflection. Is it a livable animal? Surely by making a purely ethical speech we would be pushed to say no, as for all animals. In this case, however, I think the answer is: "No!". Deep-sea animals live in areas that are so dark and quiet that they would certainly be bothered by home lighting and the comings and goings of people in a normal apartment.
Coming to a conclusion, I believe that the Nautilus is an invertebrate unsuitable for captivity and perhaps it would be better to leave it in the depths of the sea, well away from prying eyes.