Dinoflagellate Ceratium gravidum. In the video one can observe the movement of one of the two flagella. (Video : Sophie Marro)

Siphonophores - The longest animals on the planet
Cousins of corals, siphonophores are colonies of specialized individuals called zoids. Some catch and digest their prey, others swim, or lay eggs or sperm.

Seasonal evolution of the chlorophyll a concentration as obtained by the ocean color sensor SeaWiFS in the Atlantic Ocean.

Illustration in synthesized images of the seasons of the ocean: a year from the Antarctic - Animation Clement Fontana

Colony of diatoms genus Bacillaria whose single cells slide against each other (Video : Sophie Marro)

Embryos and larvae
Drifting in the currents, embryos and larvae perpetuate the species and are food for multitudes.