There are almost 20,000 species of marine fish in the world, but only a small minority is of any interest to the aquarist. Of these, most come from the Pacific and Indian oceans, although a few are native to Australia and the tropical Atlantic ocean.
Marine fish are usually collected in their natural environment and rarely reproduce in captivity. They find it more difficult to acclimatize than freshwater fish, particularly as regards feeding: some refuse to eat artificial food, and others have very special dietary requirements.
The smallest marine fish require a minimum water volume of 150-200 liters. Medium-sized species (around 20 cm) must he kept in tanks of 300 liters, or at least 400 liters if they are active. It is advisable to obtain juvenile (or sub-adult) specimens, as they are generally easier to acclimatize and feed.
Cohabitation of Marine Fish
Bearing in mind their behavior (aggression, need for territory, group life), not all marine fish can live together in the same aquarium, and any mistakes in this respect may prove tragic for your residents. The table below therefore indicates how to fill a marine tank, on the basis of the characteristic traits of each species.
Marine Fish For Beginners
The term beginners refers here not only to newcomers to fishkeeping, whose first tank will be a marine one, but also to aquarists who have already had experience with freshwater tanks. Beginners are recommended some species of clownfish (Amphiprion darkii and A. sebae) and blue damsels, all of which belong to the Pomacentrid family. Also suitable are the smaller Labrids and the Blennies (family Blenniidae). The more experienced can try, in addition to these species, other clownfish and damsels, as well as some more regal species: queen angelfish (Holacanthus ciliaris, Pomacanthidae), auriga and raccoon butterfly fish (Chaetodon auriga and C lunula, Chaetodontidae), clown and hippo tangs (Acanthurus lineatus and Paracanthurus hepatus, Acanthuridae).
For The Experience, More Delicated Marine Fish
Once an aquarist is familiar with the problems of saltwater aquariums and how to deal with them, he or she can investigate other, more delicate species: annularis angelfish (Pomacanthus annularis), some dwarf angelfish such as Centropyge acanthops (yellow and blue angelfish), all from the Pomacanthid family, the Naso and Zebrasoma genera (Acanthuridae), yellow boxfish (Ostracion cubicus, Ostraciontidae), foxface fish (Lo vulpinus, Siganidae).
On the other hand, some species can be recommended only to the most experienced hobbyists: the Pakistani butterfly (Chaetodon collare), the copperband butterfly (Chelmon rostratus), the yellow longnose butterfly (Forcipiger flavissimus), all from the Chaetodontid family. Also considered delicate are the Acanthuridae, Balistids and Pomacanthidae not mentioned above, and the Zanclidae.