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Athropoda is a phylum of segmented invertebrates which have jointed legs. This phylum includes arachnids (e.g. spiders, mites and scorpions), crustaceans (e.g. crayfish, prawns and barnacles), insects (e.g. bugs, beetles and dragonflies) and myriapods (e.g. millipedes and centipedes). Over 80% of invertebrates are grouped into the single phylum Arthropoda[1].

Quick facts

(the preferred food of some whales) are tiny marine copepod crustaceans which are thought to have one of the greatest biomasses on the planet. As such, crustaceans are a crucial component of most marine food webs[2].


The arthropods are the largest assemblage of species in the animal kingdom. Arthropods generally posses a chitin-protein exoskeleton which is divided into segments of plates and cylinders. Segmented body parts, rather than body deformation, allows athropods to move. Arthropods also moult and shed their exoskeleton as they grow in size. The number of body and appendage segments across athropod groups varies greatly, but they generally have a form of head, thorax and abdomen[3].


Arachnida—spiders and other arachnids
Crustacea—crabs, crayfish and other crustaceans
Insecta—dragonflies, mayflies and other insects

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  1. ^ CSIRO, All insects are invertebrates!. [online], CSIRO. Available at: [Accessed 24 February 2016].
  2. ^ Queensland Government (Queensland Museum), Crustaceans. [online], Queensland Government (Queensland Museum). Available at: [Accessed 26 July 2012].
  3. ^ Ruppert, EE & Barnes, RD (1994), Invertebrate Zoology, Thomson Learning.

Last updated: 12 April 2017

This page should be cited as:

Department of Environment, Science and Innovation, Queensland (2017) Arthropoda, WetlandInfo website, accessed 18 March 2024. Available at:

Queensland Government
WetlandInfo   —   Department of Environment, Science and Innovation