Aplousobranchia is an order of sea squirts in the class Ascidiacea, first described by Fernando Lahille in 1886. They are colonial animals, and are distinguished from other sea squirts by the presence of relatively simple pharyngeal baskets. This provides the etymology of their name: in Ancient Greek, ἁ.πλοος-ους (ha.ploos-ous) means "simple". The posterior part of the abdomen contains the heart and gonads, and is typically larger than in other sea squirts.

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