Classifying spiders
Garden Orb Weaver. Photo: M Gray © Australian Museum.
There are many different kinds of spiders. By studying and classifying them, scientists learn about their diversity, biology, distribution patterns and evolutionary relationships.
Australia's described spider fauna consists of about 2000 species, perhaps as little as half of the total spider fauna. Most of these species come from the eastern and southern regions of Australia. Even in the better known areas, surveys of ground spider faunas can still identify to species less than 50% of the spiders sampled.
- World-wide, about 38,000 species of spiders have been described.
- Australia's described spider fauna consists of about 2000 species
- To make sense of this diversity scientists recognise taxonomic groups, of which the most natural is the species.
- Spider species are separated from each other by differences in the structure of their mating organs (genitalia). Related species share similar genitalic structural patterns
- Related species are classified into groups called genera and related genera into larger groups called families.
- Spider families are placed within the order Araneae which forms part of the class Arachnida within the phylum Arthropoda (sub-groupings of these categories are also used).
- At each of these taxonomic levels a unique set of structural identifying features (morphological characters) identifies the particular taxonomic group. Other characters may be derived from examination of chromosomal, protein and genomic (DNA, RNA) data.
- Relationships between groups of species, genera, families, etc. can be studied by examining the distribution of derived characters within the group using cladistic techniques.
- Taxonomic keys - in the form of manual text, interactive CD-ROMs or internet-based - are constructed using key structural features to allow rapid identification of taxa.
- Taxonomic descriptions and revisions, with keys and data on distribution patterns, relationships and biology, are published in scientific journals.
Find out more:
- The major groups of living spiders (order Araneae)
- Classification of the Sydney Funnel-web Spider, Atrax robustus
