New Zealand has a number of scientific collections of plants and animals. These are part of a worldwide network of collections that ensure that the same scientific names are used all over the world. Identifying plants and animals accurately allows us to find those that are unique (endemic) to New Zealand, and recognise harmful introduced organisms.
The internationally accepted system of classifying and naming plants and animals – called taxonomy – was developed by the Swedish naturalist Carl Linnaeus in the 18th century.
This system classifies living organisms in a hierarchy. Organisms are first assigned to a kingdom – for example, the animal or plant kingdom – and then to progressively smaller groups: phylum, class, order, family, genus and species.
A New Zealand company that had exported milk powder to the US was told that its product was contaminated with insects, and it would have to pay for fumigation. Scientists in New Zealand compared the bugs with those in the arthropod collection at Landcare Research. They showed that the insects had never previously been recorded in New Zealand, and probably got into the milk powder in a US warehouse.
A species is a group of organisms that is seen as distinct from other groups – for example, tūī and bellbird are two different species of birds. A species is often defined as a group of individuals that can or do interbreed in nature. However, there are exceptions. Some separate but related species may interbreed and hybridise. Other species may reproduce asexually.
Naming a species
The scientific name of each species has two parts, both in Latin: a collective name for the genus and a species name.
When a new species is found, there are rules about how to name it.
- Every name must be unique.
- A description and illustration must be published in a scientific journal.
- A specimen must be chosen for a collection that other scientists can access. It is known as a type specimen.
- If the same species has been given several names independently, the oldest name has priority.
There are international codes of zoological and biological nomenclature, with detailed guidelines to ensure stability and sort out disagreements about scientific naming.