Scientific names, or taxonomic names, are the unique nomenclature used in biology to refer to specific species. The purpose of these names is to standardize species names across regions, languages, and cultures to avoid confusion and ambiguity.
While these Latin names may seem intimidating (they even confuse journal editors), they become easy to use once you understand where they come from and how to use the formatting, notations, and abbreviations associated with them.
What is scientific/binomial nomenclature?
In the 1750s, Carl Linnaeus developed the system of binomial nomenclature (a two-part naming system) that we use today to name and classify living things. Species names consist of two parts: the first part is the generic name (genus name), while the second is the specific epithet (species name).
Species with the same generic name are closely related species grouped into the same genus. The specific epithet by itself is meaningless, almost like an adjective without a noun. Unrelated species can have the same specific epithet, such as Melilotus albus (white sweetclover) and Procnias albus (white bellbird). Albus means white.
Some animals have species names where the specific epithet repeats the genus name, such as Gorilla (Western gorilla). This is called a tautonym. While often used in animal names, tautonyms aren’t allowed in plant, fungi and algae names according to the International Code of Nomenclature for Algae, Fungi, and Plants guidelines.
Some examples of common and scientific animal names:
Some examples of common and scientific plant names:
Rules for writing scientific names of plants and animals
Scientific names are made up of Latin, or latinized, words. The scientific name often describes some aspect of the organism. For example, the blue jay’s scientific name is Cyanocitta cristata, which means chattering, crested blue bird.
Sometimes, species are named after a person (e.g., a black-eyed satyr butterfly, Euptchia attenboroughi, was named after David Attenborough), or the place where it occurs (e.g., the Arabian gazelle is called Gazella arabica).
How to format scientific names
Scientific names are in Latin, so, similar to other words from foreign languages, they’re always written in italics. The generic name is always capitalized, while the species epithet is never capitalized.
If the species name appears in a sentence where the text is already italicized, such as in a heading or figure legend, the species name can be unitalicized to distinguish it from the rest of the text. If written by hand, the name should be underlined.
How to abbreviate scientific names
If a species name is repeated multiple times in a written piece, such as a research paper, it can be abbreviated after the first time the name is written out in full. For example, the mosquito Anopheles stephensi can subsequently be abbreviated as A. stephensi. In the same written piece, you can also refer to another species from the same genus in the same way, such as A. funestus. In some journals, this must be done in both the abstract and main text of the paper.
If there are two genus names in the text that start with the same letter, the genus name can be abbreviated using its first two letters.
For example, if you also mention Aedes vexans mosquitoes in your text, you can abbreviate the two species as An. stephensi and Ae. vexans.
However, as with all abbreviations, these abbreviations should be used sparingly and only if there is no possibility for confusion. Only use an abbreviation if you use the term multiple times in your text. The general guideline is three or more times, but this will depend on the length of your text, so use your own judgement.
Always keep your reader in mind. If there are genera with similar names, rather write them out in full. If you only have one species name in your text that you use repeatedly, abbreviating it is not a problem, but if you mention 10 different species, abbreviations could confuse and frustrate your reader.
When referring to an unknown species in a genus, you can write the generic name followed by the abbreviation “sp.” The plural form is “spp.” The abbreviation “sp. novo” indicates a species that hasn’t been described yet.
For example: “During their bat survey in Guinea, they caught a Myotis sp. in one of their traps. Its distinctive coloring set it apart from other Myotis spp. and they knew it had to be a new species. The discovery of Myotis sp. novo highlights the importance of these surveys.”
How to add the taxonomic authority of a scientific name
Sometimes, the taxonomic authority is added to the scientific name. The taxonomic authority is the surname of the person who first described the species.
In plant names, the taxonomic authority is abbreviated (e.g., Panicum virgatum L., where the L is the abbreviation for Linnaeus). In animals, the surname is written out in full followed by the date when it was first described (e.g., Balaena mysticetus Linnaeus, 1758). A name following in brackets means that the name has been amended subsequent to first descriptions (e.g., Pulchrapolia gracilis (Dyke and Cooper).
How to indicate subgenus, subspecies, form, and variety
Other information that can be added include subgenus, subspecies, forms, and varieties. Subgenus is a classification level below genus, but above species level. If a subgenus is included in the scientific name, it’s placed in parentheses between the generic and specific name, with the first letter capitalized, for example Nereis (Hediste) diversicolor.
A subspecies is a further division of a species into groups of individuals that are distinguishable, but not different enough to be classified as a separate species. In animal names, the subspecies name is written after the species name, in lowercase italics. For example, the Bengal tiger is Panthera tigris and the Sumatran tiger is Panthera tigris sondaica. The Bengal tiger is found in India, while the Sumatran tiger is only found on the island of Sumatra and is much smaller than the Bengal tiger. Despite the differences in their distribution and appearance, they can interbreed, making them subspecies and not different species.
In plant names, the abbreviation subsp. is added between the species and subspecies name. For example, Cornus sericea subsp. sericea.
A variety is a population of individuals with distinct, inheritable differences and are indicated with the abbreviation var., for example Gleditsia triacanthos var. inermis refers to the thornless variety of the thorny honeylocust. Form refers to occasional variations in individuals, such as variation in flower color. For example, Cornus florida f. rubra refers to individuals of the flowering dogwood with pink flowers instead of the usual white.
How to write the name of a hybrid
Hybrids are indicated with an “x”. Hybrids that have been named are written with the x between the genus and species name. For example, Solanum x procurrens is the hybrid between S. nigrum and S. physalifolium. If a hybrid hasn’t been named, or if you want to specify the parentage, the same hybrid can be written as S. nigrum x S. physalifolium.
How to write the name of a cultivar
Cultivar names are written inside quotations, capitalized, and not italicized. If the cultivar was bred from a single species, the cultivar name follows the specific epithet; for example Zea mays “Wisconsin 153.” If the cultivar was bred by hybridizing several species, the cultivar name replaces the specific epithet, for example, Rosa “Iceberg” is a cultivar derived from crosses between Rosa chinensis, Rosa multiflora, Rosa gigantea, and several other Rosa spp.
Can two species have the same scientific name?
When two genera from the same kingdom have the same name, this is called a homonym. This is similar to homonyms in grammar, which refers to words with the same spelling but different meanings. While homonyms aren’t allowed in scientific nomenclature, errors sometimes slip through as shown in this online list of homonyms. For example, Colobus is a genus of beetles and a genus of primates.
When two genus names from different kingdoms have the same name, this is called a hemihomonym. For example, Ficus is a genus of plants and a genus of snails.
Hemihomonyms are allowed since the scientific names of different kingdoms are governed by different regulatory bodies. The International Code of Nomenclature (ICN) governs the naming of algae, fungi, and plants, while the International Commission on Zoological Nomenclature (ICZN) regulates the naming of animals. A recent publication highlighted the problem with and extent of this phenomenon and compiled an online list of hemihomonyms.
It can happen that two species from generic hemihomonyms also have the same specific epithet, resulting in identical scientific names. In the previous example of the hemihomonym, Ficus, there’s both a sea snail and a fig named Ficus variegata. Another example is Orestias elegans, which is the scientific name of both an orchid and a fish.
Resources for finding scientific nomenclature
The Integrated Taxonomic Information System (ITIS) and The Catalogue of Life are online data bases where you can find the scientific name of any life form by searching either the common name or the scientific name. They provide the full taxonomic classification, from kingdom to species level, the taxonomic authority, and references to the publications where these species were described.
The IUCN Redlist is another trusted source and provides a list of animal, plant, and fungi species with their taxonomic information and conservation status details, including population numbers, distribution, and current threats.
However, species names can change when new taxonomic information becomes available. Keeping track of the taxonomic changes of all organisms is a huge task. While the above-mentioned lists are a good starting point to finding a species name, do some further research to be sure you have the latest accepted scientific name.
A scientific name in a database might have been correct at the time it was last updated, but it could be outdated. For example, the name of the sweet thorn tree was changed to Vachellia karroo as described by Banfi and Galasso in 2008. However, in the ITIS database, Acacia karroo is still listed as the correct name, while the IUCN Redlist and The Catalogue of Life have the correct accepted name, with Acacia karroo listed as the synonym.
Region- or taxon-specific resources such as recent, regional field guides or online databases are often better resources. For example, a good reference for bird species would be the Birdlife International website. The World Register of Marine Species (or WORMS) is a database of marine organisms. However, the gold standard would be the most recent taxonomic publications on the species.
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