Cyclopoida


The Cyclopoida are an order of small crustaceans from the subclass Copepoda. Like many other copepods, members of Cyclopoida are small, planktonic animals living both in the sea and in freshwater habitats. They are capable of rapid movement. Their larval development is metamorphic, and the embryos are carried in paired or single sacs attached to first abdominal somite.
Cyclopoids are distinguished from other copepods by having first antennae shorter than the length of the head and thorax, and uniramous second antennae. The main joint lies between the fourth and fifth segments of the body.
The Cyclopoida contain 30 families:
Several more families are included in Suborder Poecilostomatoida, a temporary name for the "poecilostome lineage" The Poecilostomatoida were previously treated as a separate order, but molecular phylogenies show that this lineage is nested within the Cyclopoida.