Although most of the reef fishes in our aquariums are imported from the tropical Indian and West Pacific oceans, some of the more popular imports are instead from the Caribbean, home to a Western Atlantic fauna. One such fish is the tobaccofish or tobacco bass, Serranus tabacarius, which is distributed from Florida to Brazil. This is a common, carnivorous fish that grows to 22 centimeters or just under 9 inches. More commonly they are 16 centimeters or over 6 inches long. Although the Caribbean members of the genus Serranus are referred to as 'basses', this word may denote a number of other percomorph fishes, and is thought to have initially referred to freshwater percids - from a root word for a spine or thorn.
During the genesis of our modern English language, the word 'bass' came to refer to the saltwater moronid fishes of European shores; the percids came to be referred to by words that have other etymologies, although the cognate 'baas' is still used in modern German, and is understood to conserve the original meaning. Other marine fishes called 'basses' are so named for their similarity to the European percids and moronids - ambush predators with large maws. As a rule of thumb, the freshwater fishes of these types tend to be called perches, and their marine counterparts basses; but it is not a strict rule, nor is it zoologically inspired. As Europeans explored colonized the world, they encountered previously unknown fauna and flora, that they had to give vernacular names. Often these were references to European animals, ie. American badgers and porcupines, and Australia's native 'cats' and marsupial 'mice'.
The genus Serranus is related to the fish we call groupers, hinds, and fairy basslets or anthias. In the Western hemisphere, English speakers may refer to the Serranus genus as 'dwarf basses' although they actually vary in size, and some species do become larger. The tobaccofish is too big to be comfortably described as a basslet, a name for a number of small serranids and superficially similar fishes, though they are sometimes mistreated as such - they grow too large for nano reef setups. In British English, the Serranus genus are usually called the combers. These are slender predators that evolved to hunt crustacean prey. The genus has been very successful in the Caribbean and surrounding waters, but as they are far from the Indo-West Pacific, they are usually underestimated as aquarium fishes.
Tobaccofishes are seen by divers at shallow depths, over low relief rock and coral bottoms, in clear water conditions. Reportedly they are found as derp as 70 meters, and it seems that they are mildly gregarious at deeper depths than when they are in more shallow water, in which situation they are seen hunting alone. This species is noted to be commonest on rhodolith plains, or swathes of coralline algae. Members of the genus Serranus are suction feeders, which limits the size of prey that they are able to handle. Although they will eat other kinds of prey as well, their primary diet is arthropods, and they are regarded by ecologists as crustaceivores.
Tobaccofishes are often seen following another kind of fish, the goatfishes - schooling, benthic foragers - that rove around in groups in search of small prey hidden in the seabed. Disturbed and fleeing animals understandably move away from the goatfishes, and into the jaws of the waiting tobaccofishes. Such behaviors in the animal kingdom are not unique to tobaccofishes, but it is an interesting and charming behavior. It is actually similar to the way seagulls and the crow family follow tractors, or egrets that associate with herds of cattle, to seize upon the insects avoiding their hooves.
In the aquarium, all Serranus species are harmless to other fish if they are too large to be inhaled as potential prey. Due to their niche on the reef, however, they will consume smaller fishes and other vagile animals, especially shrimp. Due to their diets and the way they identify items as foods, Serranus are harmless to sessile organisms such as corals. There are records of other species of Serranus consuming small echinoderms. Part of the appeal of tobaccofish in the aquarium is that they are diurnal hunters, whereas many of their fellow serranids are nocturnal. They have the habit of sleeping under stones, so all rockwork must be safe and stable. Naturally they eat fresh or defrosted, meaty foods.