Nannastacidae is a family of crustaceans belonging to the order Cumacea. They have no free telson. The endopods (interior branches) of the uropods are present on one segment. There are exopods (outer branches) on the maxillipeds and generally one on pereopods 1–4 in males and 1–2 in females. In the females the second antenna is much shorter than the first. It contains the following genera:

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