Copepods are small crustaceans that can be found almost everywhere, where water is available. Most of the 12.000 known species live in the sea, and are the biggest biomass in the oceans. Sometimes they are known as the insects of the sea. Mainly, they swim the through the water, burrow through the sediment at the bottom of the seas, found on tidal flats and in the deep sea trenches. One third of all species live as associates, commensals or parasites on invertebrates and fishes. One of the hotspots where copepods are present are the tropical coral reefs in the Indopacific, and some coral species hosts to up to 8 copepods.(Johannes Dürbaum & Thorsten-D. Künnemann )

How they move:

"The locomotion of species that live on the sea-bottom or on water plants is different. The four first swimming legs are primarily used for a kind of swimming-crawling. Their cylindrical body wriggles around between obstacles or over the substrate( Johannes Dürbaum & Thorsten-D. Künnemann )."