Plankton collected during winter in the bay of Villefranche-sur-Mer, using a 0.2mm mesh net. The longest organism here is the pteropod mollusc, measuring about 7mm.

The life cycle of Pyrocystis lunula includes a phase known as the coccoid stage, during which cells at different stages of division are contained within the same shell.

Phronima sedentaria uses two large claws to catch its prey. The claws can change colour by means of pigmented cells.

Gripping the inside of its barrel with two front and two hind legs, this phronima moves its tail to swim with the currents.

Plankton collected in Shimoda bay in autumn with a 0.2mm mesh net. Organisms measure a maximum of 5 to 7mm.

Diatom and dinoflagellate bloom in Toba Bay.

Diatoms in chains: Thalassionema nitzschioides is a pennate diatom. The cells, each measuring 10 to 20 microns, are joined together in chains by mucilaginous links

Two solitary diatoms. These centric diatoms measure 100 to 200 microns (0.1-0.2mm). The small particles within the cells are chloroplasts. Left: Odontella sinesis. Right: Odontella mobiliensis

Four pink-coloured female gonads surrounded by four oral arms and eight tentacles lie beneath the umbrella of Pelagia noctiluca.

Juvenile galathea. This small crustacean (2mm) survived for a few days aboard the schooner Tara during our voyage in the Indian Ocean. With repetitive, robot-like motions the juvenile squat lobster used its pincers to clean its antennae and collect the edible particles clinging to bristles on its legs.

Penaeid shrimp larva Solenocera crassicornis. Collected in the bay of Villefranche-sur-Mer.

Female sapphirina copepod.

A close-up of the compound eyes of a megalopa larva.

Oceania armata. Its closely related cousin, Turritopsis dohrnii, was recently featured in the media as an example of an organism that may achieve immortality.

Tomopteridae polychaetes such as this Tomopteridae annelid Eunapteris sp. can measure just a few millimetres, or tens of centimetres.