Word About Species Names...
Many people wonder why
scientists use complicated, hard to pronounce names when speaking about familiar
animals and plants. Common
names such as blue crab, redfish, and dolphin are successfully used in casual
communication, and convey an immediate idea of what a particular animal or plant
like. Scientists avoid using common
names because they are often not specific to a particular species. For
instance, the blue crab is only one of many species of crabs
that can be described as blue. In the Indian River Lagoon alone, there are
several species of "blue crabs": the blue crab (Callinectes
sapidus), the lesser blue crab (Callinectes similis), the red blue
crab (Callinectes bocourti), the ornate blue crab (Callinectes ornatus),
and the blue land crab (Cardisoma guanhumi).
Common names can also be
confusing in other respects. Another familiar problem occurs when a species has more than one common
name. For example, the striped mullet, Mugil cephalus, is found all
over the world, and has a variety of common names (striped mullet, black mullet, sea mullet, flathead mullet,
and gray mullet) which are used in different regions. Still
another problem arises when a species is so obscure that it has no common name.
Thus, to avoid any confusion or ambiguity in scientific research, biologists use scientific names in identifying species.
What's in a Name?
The system of naming species was first developed by Swedish botanist and
physician, Carolus Linnaeus in the mid- 1700s. Linnaeus is the father of
the branch of biology called taxonomy, which seeks to describe, name and classify
organisms. His system of naming species, still in use today, begins with
assigning all species a two-part Latin name called a binomial. The first
word of the binomial is the genus name of the species, and the second word is
the specific epithet for the species. For example (see figure above), the scientific name
for the blue crab is Callinectes sapidus. Callinectes,
the genus name, is the collective term which includes many species of crabs closely related to the blue crab. The specific epithet, sapidus,
describes exactly which of the Callinectes species is being
How does Taxonomy Work?
Linnaeus' original classification system
is based on 2 main goals. The first is to distinguish between
closely related species and assign them as separate species based on differences
in specific traits called diagnostic characters. The second goal of
taxonomy is to organize groups of similar species into broader and more
collective categories. For example, the species name for the
domestic cat is Felis catus. Felis denotes the genus name
for this species, while catus denotes the unique specific epithet for the
The housecat is closely related to several other feline species
such as the bobcat, Felis rufus, and the cougar, Felis concolor,
so they are all placed in the same genus.
Members of the genus Felis are also
related, though less closely, to other cat genera such as Panthera, which
includes lions, leopards and tigers; and Leopardus, which includes
the ocelots. Because the members of all of these genera are cats, they can
be grouped together under the family Felidae.
At the Order level, cats are grouped with
other animals that are quite different in physical appearance and general
behavior, but with whom they share other basic attributes. In this case,
cats, dogs, bears and some other groups are all predators that hunt and prey
upon other animals. They are thus grouped together in the Order Carnivora,
which includes meat eating animals.
At the Class level, cats and other
predatory animals are grouped with non-predators with whom they share specific
biological traits. In this case cats, dogs, bears, sheep, horses, cows,
giraffes, whales, and many other groups, including people, belong
to Class Mammalia (mammals). All mammals have hair, are warm-blooded, and give birth to live young which feed
via mammary glands.
At the Phylum level, cats are included with all other
vertebrate animals in the subphylum Vertebrata, in the Phylum Chordata.
This large grouping includes all animals having either a notochord, or an actual
spine. Lastly, the most inclusive taxonomic
grouping is the Kingdom. Biologists often delimit the basic taxonomic groupings used to
classify all living things into a 5 kingdom scheme. Kingdom Monera
includes all the bacteria and other Prokaryotic cell types; Kingdom
Protista includes all the algae and single celled Eukaryotes; Kingdom Animalia
includes all the animals; Kingdom Plantae includes all the plants;
and Kingdom Fungi includes all of the fungi and molds.