Arthropoda

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Arthropods (phylum Arthropoda) are the phylum which includes insects, crustaceans, and all organisms with a hard shell-like segmented body, such as spiders, horseshoe crabs, and centipedes.

Identification[edit]

Arthropods have a hard outer shell, or exoskeleton, which is periodically shed and regrown. The body is segmented, usually with 2-3 distinct groupings. Paired and segmented appendages are usually present.

Life Cycle[edit]

With the exception of insects, arthropods undergo little to no metamorphosis. Immature arthropods resemble adults. A few crustaceans have a immature form that differs significantly from that of the adult. Some Celicerata have fewer legs in the immature form.

Habitat[edit]

Arthropod habitats are very diverse. Arthropods are found in almost every habitat. Feeding is equally varied.

Taxonomy[edit]

Formerly, arthropods were divided into only two subphyla, Manibulata and Celicerata. Mandibulate arthropods include crustaceans, hexapods, and Myriapoda.

Number of species[edit]

There are 104,000 species found in North America, and 840,000 worldwide.

Subdivisions[edit]

There are 4 subphylums in this phylum.