Tanaidacea
From Wikipedia, the free encyclopedia
Tanaids | ||||||||||||
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Tanaisus lilljeborgi
(a tanaid from the North Sea) |
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Scientific classification | ||||||||||||
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Families | ||||||||||||
Family Anthracocarididae
Superfamily Apseudoidea
Family Neotanaidae
Superfamily Cretitanaoidea |
Tanaids (order Tanaidacea) make up a minor crustacean group within the class Malacostraca. There are about 940 species in this order.
[edit] Morphological characteristics
Most tanaids are small (2 to 5 mm long), but adult size reaches 0.5 to 120 mm. They have a carapace formed via fusion of the first 2 thoracic somites. They also have chelate first pereiopods, 6 free thoracic somites, 5 abdominal somites bearing pleopods and a pleotelson with a pair of terminal or subterminal uropods.
[edit] Habitat
Most are marine, but some are also found in freshwater coastal habitat or estuaries. They can live in very deep water environment, exceeding for some species 9,000 m. In some deep sea environment, they represent the most abundant and diverse fauna to be found.
[edit] Life cycle
Tanaids do not undergo a true planktonic stage. The early developmental period is spent while young are within the marsupium of the mother. Subsequently, post-larvae, called mancas, emerge as epibenthic forms.