THE COMMON DOLPHIN COULD BE THE POSTER FISH FOR THE SCIENTIFIC SYSTEM OF SPECIES NAMES. Yep, poster fish, not one of the 40 or so species of the charismatic marine mammals. This one’s definitely a fish, despite its common name.
The fishy dolphin is shaped vaguely like a baseball bat with a long dorsal fin and a dour expression. Found in open waters around the world, it’s regarded as a good sport fish, as a good commercial food fish – and as good eating.
A FISH OF MANY ALIASES
And as interpreted by the Florida Museum of Natural History, the common dolphin – the fish – has more than 80 localized names around the world, from “masimasi” in Samoan to “chapeau governeur” in French. If you’ve eaten dorado in Latin America or mahi mahi in restaurants in North America, you’ve eaten dolphinfish. Mahi mahi itself is taken from the Hawaiian language, adopted for its exotic sound by seafood sellers who saw a market for a tasty fish.
WHY SPECIES NAMES MATTER
The scientific naming system was created in order to talk about masimasi, mahi mahi and chapeau governeur and know for sure you’re what talking about – in this case, a Coryphaena hippurus. This isn’t to say that marine biologists stand around chatting up Latinized species names like Coryphaena hippurus all the time.
Rather, it’s that the accepted convention of citing an animal or a plant and indicating its scientific name right afterwards ensures that everyone knows they’re talking about the same slice of life.
ENTER CAROLUS LINNAEUS
The system for species names grew from the work of Carl Linnaeus, a Swedish professor who was the most famous scientist of the 18th Century. He didn’t so much invent scientific classification as standardize the use of binomial nomenclature for individual animals. It was already a well-established convention to name things in Latin, the universal language of erudition, so his Latinizing wasn’t an affectation.
If this seems cumbersome today, remember that while we’re stuck with it, so was Linnaeus. Writing in Latin, he became Carolus Linnaeus.
Linnaeus recognized classes, orders, genera and species – and got a lot of things wrong. But the 10th edition of his Systema natura, published in 1758, is regarded as the starting place for binomial nomenclature and from there the scientific approach to species names has been expanded, tinkered with and refined.
The definition of species can seem a little circular – groups of organisms that are like each other (see “The Specifics of Species – By the Numbers”). Not only do they have to have genetically determined traits in common, they must be able to breed with other group members to produce offspring with the same traits, and be unable to produce fertile offspring with members of other species.
Still, taxonomists make a point of emphasizing that there are no such things as explicit characteristics that rigidly define phyla, species or any other rankings. Damselfishes, black bears, bristleworms, day lilies and cyanobacteria all represent species in their very different kingdoms and phyla, each with their own sets of genetic characteristics that they pass on to succeeding generations. That’s what matters. And it’s why a systematic approach to species names matters.
Nowadays, the rules for biological names are laid out by worldwide scientific conventions like the International Commission on Zoological Nomenclature.
Beyond actually finding it, the most difficult part of identifying a new species is proving that it’s new. This requires research through books and journals to see if it’s been described somewhere. A holotype – or single, representative specimen – must be placed in the collection of a reputable institution where other taxonomists can examine them and described in a peer-reviewed article in an appropriate journal.
USING BINOMIAL NOMENCLATURE
While the species is the most basic division of classification, a species name is not really very exacting. The northern lobster may be Homarus americanus but the black bear is Ursa americanus. This theoretically leaves room for dangerous confusion if only the species names were in play. Rather, the binominal naming system combines an organism’s genus name and its species name, generally referred to as its species epithet.
Actually, the only real rule for coming up with new species names is that it has to be Latinized. That doesn’t mean it has to be a classical Latin term. A lot of organisms are named descriptively, as with Spirobranchus giganteus, a Christmas tree worm with large spiraling gills. Some species are named after their finder or in honor of someone else, as with, apparently, Periclimenes pedersoni, the Pederson cleaning shrimp.
ABBREVIATING BINOMIAL NOMENCLATURE
In addressing an individual species in an article, the convention is to write out both the genus and species name in full on first reference and then use only the genus initial with the full species name in subsequent mentions. Thus, our Pederson cleaning shrimp in the next mention would be P. pedersoni.
Another convention is to italicize genus and species names but not family, class, order or any of the other terms. I don’t know why.
PRINCIPAL SOURCES: Marine Biology, Fourth Edition, Peter Castro, Michael Huber; All Species Foundation; “Explore Biodiversity, Topics in Diversity and Evolution,” www.explorebiodiversity.com; Britannica Online Encyclopedia; “Naming a New Mollusk Species,” Thomas E. Eichorst; “Dolphinfish,” Florida Museum of Natural History.