Taxonomy: assigning the "right" scientific name
Taxonomy is the art or science of giving the "right" scientific name to organisms. Taxonomy used to chug along in a scientific backwater, but for the last couple of decades, taxonomy has been in a revolutionary uproar. New techniques that involve sequencing mitochondrial and ribosomal DNA are providing biologists with entirely new bases for confirming or rewriting the historical family relationships of species, in the genealogical patterning of cladistics. Perhaps gene sequencing offers sounder evidence than the traditional comparisons of body structures, such as shapes of teeth and fin-ray counts. The new area is sometimes called "molecular systematics." I thought when I first posted this in 2002 that in another decade or so, the dust will have settled, and it has: cladistics is the new norm, though some large groups like the Characiformes remain to be disentangled.
"The value of scientific names is that they unlock the door to information hobbyists will need to be successful," wrote Kathleen Wood, when she was editor of Aquarium Fish. When you see people posting simple requests for the most fundamental information about their fish at web forums, generally you'll note that they only have a "common name" for the fish. Armed with the authentic scientific name of a fish, you can google it or find it at FishBase. Some of what you turn up will be over your depth, but you'll never really learn to swim if you can always touch bottom.
It certainly helps to have one agreed-on name for the fish that you're talking about. Especially if you can keep up with what that universal name currently is. Names have been changing, and a fishkeeper just has to go with the flow. It's wholesome that scientific names are changing: the changes reflect that information itself is in flux. It's surprising to me to watch aquarists sometimes get involved in discussions over the right naming of the fishes we enjoy keeping. I know I'm not competent to judge. Maybe aquarists should take a tip from gardeners, who are wise never to wade into scientific discussions about species and their naming. Instead, sensible gardeners adapt a tip from Lord Chesterfield: never to be the first to take up a new genus designation, nor the last to leave behind an old one. When you're fretting over the latest change in the names of Lake Malawi cichlids, it's good advice.
Making an end run round such difficulties, gardeners have that good old disclaiming designation "of gardens." Since I don't have any legit independent opinion on such questions, I sometimes use the expression "of aquariums:" to write of "Puntius tetrazona of aquariums" helps avoid controversies that surround Barbus versus Puntius, or perhaps Pethia, not to mention Capoeta.
Still, sometimes you want to check the latest opinions about where your fishes fit in the Tree of Life. This international collaborative web project, which links individual phylogenetic diagrams of related families or genera with one another to form the whole vast tree is just beginning to fill out; it already offers a good general orientation to the modern teleost fishes. Check out its general orientation page and the Tree of Life structure. The Taxon pages formerly at Ichthyological Web Resources have been superceeded by Google and other search engines, and by FishBase.
The veteran Swedish ichthyologiust Sven Kullander made the fooferaw over naming of the fruit fly Drosophila melanogaster the subject of his almost-monthly blog in April 2010.
The variety of fishes Americans keep. A manual on breeding Tiger Barbs from the Center for Tropical and Sub-Tropical Aquaculture, Hawaii, notes that a 1992 analysis of species of tropical fish imported into the U.S. revealed that twenty species accounted for over 60% of the total number of specimens. The authors didn't seem to think this was as healthy a spread as I do. Look at it the other way: almost 40%, that is, two of every five imported fish sold, were species that weren't represented among the twenty most common species of tropical fishes. Are two out of five of the fishes in your tanks right now to be counted among the less common species?