What's In A Name? - Part One By David Rentz

 

The two-word system we use (genus and species) is called the 'Binominal System of Nomenclature'. It was devised by the Dahish scientist, Linnaeus, in a series of ‘Systemae' begun in 1739. It literally means 'two name system'. He published twelve editions, the last of which appeared in 1768. The 'two name system' was first employed consistently in his Tenth Edition of 1758. This is the starting point of the Binominal System we use today.

 

The reasons for the development of an international naming system are quite obvious. Communications among countries was becoming commonplace in the late 1700's and a mammal or bird that might be called by a name in one country might be called by another name in another country or even the same country. For example, the Mallard duck, scientific name Anas platyrhynchos, in America alone is called greenhead, gray duck, English duck, stock duck and by some. thirty other names. It has only one scientific name. A different example using birds is seen with the name Magpie. The Australian species is not closely related to the American and European species for which it was named by early settlers. Using fish examples, how many different and unrelated fish can you think of named 'bass'? The scientific name, however, defines one kind of bass. This provides a basis tor communication.

 

Scientific names are mostly derived from the Latin language. Why Latin? At the time Linnaeus was working, Latin was considered the only international language and the language of scholars. To this day legal documents in some countries are still being written in Latin. So it was natural tor Linnaeus to have chose that language. No matter what language a scientist uses in the text of his books or articles, the scientific name of his animals are always the same.

 

Linnaeus' system is based on the logical hierarchy of organisms. Using the guppy as an example consider the following:

 

 

One can ascend up the hierarchy much further but for our purposes, the above is sufficient. Each family generally consists of a number of genera (Latin plural of genus) and above that level other genera in the family Cyprinodontidae are classified exactly as the guppy.

 

There are a few basic rules that are standard conventions which you may have already detected. In animals, the family name always ends in 'idae'. Each genus begins with a capital letter and the species name always begins with a small letter. This is true even if the species is named after a person such as the Black Neon Tetra, Hyphessobrycon herbertaxelrodi, or Hart's Rivulus, Rivulus harti. The genus and species names are always italicised (printed in Italic characters) or underlined (when in English),

 

You May also have noticed that frequently after the Latin name there is the name of a person, often in brackets. This is the author's name, that is, the name of the person who first described and named that species. If the name is enclosed in brackets, this indicates that the species was originally described in a different genus from the one in which it is now placed. To a person who wants to find more about a species, the presence of brackets around the original describer's (author's) name signals that some work has been done on the group after the original description of the species. To cite the examples above, the Guppy Poecilia reticulata (Peters), was originally described by Peters as Lebistes reticulata, but later transferred to the genus Poecilia by another author. You will discover that most fish have been originally described in genera other than the ones they are in now. This is because there is much 'taxonomic' (the study of the classification of organisms) interest in fishes and new discoveries often lead to the other. And, not too infrequently, a taxonomist discovers the original genera was the proper one for the species after all. This is all very confusing to the non-specialist but it is generally not unexplainable. Incidentally, you way have noticed the name of the Carp as Cyprinus carpio (Linne). The author is actually Linnaeus. After he was knighted he became Baron Karl von Linne and the species he described after that event have his name spelled that way but it is, in fact, the same person we have been talking about.

 

You may have seen this combination as the scientific name of the green discus fish A Symphysodon aequifasciata aequifasciata (Pellegrin). This three part name indicates that a taxonomist has divided the species Symphysodon aequifasciata into subspecies. Subspecies (also known as races) are populations that have some characteristics in common with one another but differ slightly from other populations. Subspecies are based solely on geographical separation. The members of one subspecies are able to successfully interbreed with members of another subspecies but being separated geographically (in the case of the discus by different rivers and lakes in brazil) they rarely come together in nature. Of course, in our aquariums anything can happen!! By definition two subspecies of the same species cannot occur at the same locality. It they do, then either the taxonomist has made an error or a catastrophe, such as a flood or river-course change caused by an earthquake, has occurred to get them together. When, and it they do, their distinctive characteristics will be 'blended' in their offspring.

 

To follow up on the subspecies situation, in the discus fish we have the following combinations which were listed in the 1976 version of Axelrod et al. loose-leaf 'Exotic Tropical Fishes'.

 

 

 

All of the above occupy different river or lake systems in Brazil. They have distinctive characteristics but can, and do, interbreed freely with one another producing fertile offspring when they are given the opportunity in an aquarium.

 

Generally, the scientific names have logical meaning. Many Of the names are from Latin origins, others are from Greek. There is no general rule for this but it is usually so. Once you begin to pull apart some of the words and learn their derivatives, you will find the names more interesting and meaningful. In the next part we will look at some familiar names and their origins.

 

End of Part One.