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Christmas Gift Guide

Pulsating neon rainbow

The queen of the Xenomorphs?

Miniature cyclops

Tiny and abundant

Shell of glass

Shimmering iridescence

Tiny squid

Snacking jellyfish

Underwater wings

Ancient worm of the sea

In a special issue of Science magazine, a team of 160 scientists has published a series of papers detailing the findings of the Tara expedition. What did they discover? A massive world of microscopic creatures dwelling in seas all around the globe.

Comb jellies are the largest animals that use combs of hair-like cilia for swimming. This is one of the smaller species, which start at just a millimetre or so in length, but larger species range up to 1.5 metres.

When comb jellies swim, the rippling of their cilia causes light to refract, resulting in a rhythmic rainbow of neon colours. You can see a video of this effect in action here, and another here.

Caption by / Photo by Christian Sardet, "Plankton -- Wonders of the Drifting World", University of Chicago Press, 2015

This semitransparent prawnish-looking creature is an amphipod -- a type of crustacean with no carapace.

The female of the species feeds on jelly-like salps, leaving just a hollow gelatinous shell behind. It will then climb inside and use the empty barrel-shaped shell of the salp as a sort of mobile home, sailing the seas and snagging food, keeping her young safe inside.

Rumour has it that the tiny amphipod inspired the design of the Alien queen, Xenomorph Regina, from James Cameron's 1986 film, "Aliens." It's never been confirmed, but the resemblance is uncanny.

Caption by / Photo by M. Ormestad/KahiKai/Tara Oceans

Copepods -- a group of tiny crustaceans -- live all over the ocean. Some live on the seafloor, but this blue specimen was retrieved drifting in the ocean's current.

Most copepods are very small, measuring just a millimetre or two, and have a single compound eye in the centre of their transparent heads.

Caption by / Photo by Noan Le Bescot/CNRS/Tara Oceans

These little fish in the genus Cyclothone grow to just 6 centimetres long, and live at ocean depths greater than 300 metres.

This makes them difficult to catalogue, but the numbers found are extremely abundant. Although it is a small fish, ichthyologists theorise that the Cyclothone genus contains more individuals, and possibly more biomass, than any other fish genus in the world.

Caption by / Photo by M. Ormestad/KahiKai/Tara Oceans

At 200 microns (0.2 millimetres), Lauderia annulata is one of the largest known kinds of single-celled algae. This one was found in the Indian Ocean.

The green and yellow speckles are chloroplasts, the algae's food-producing organelles; the entire organism is encased in a shell of silicon dioxide, a type of naturally occurring glass, similar to quartz or sand.

Caption by / Photo by Christian Sardet/CNRS/Tara Expéditions

This copepod, found in the Mediterranean Sea, is called Sapphirina -- the Sea Sapphire.

The male shimmers with an iridescent array of colour, created by microscopic layers of hexagonal crystal plates inside its skin cells. You can see a video of the phenomenon here.

To reproduce, the females parasitise salps. Poor salps, they can't seem to catch a break.

Caption by / Photo by Christian Sardet/CNRS/Sharif Mirshak/Parafilms/Tara Expéditions

A tiny squid hatchling.

Caption by / Photo by C. Guiguand/Tara Oceans

The Lyriopemedusa is a very small jellyfish, measuring just 10 to 30 millimetres across. This individual has caught and devoured a juvenile fish in its tentacles. Photographer and Centre National de la Recherche Scientifique research director Christian Sardet captured the process.

Caption by / Photo by Christian Sardet, "Plankton -- Wonders of the Drifting World", University of Chicago Press, 2015

On the right, with what looks like butterfly wings, is what is known as a sea butterfly (funnily enough).

Sea butterflies are a type of sea snail, that, unlike their mollusc cousins, can swim, using a foot that forms a pair of wing-like flaps. It lives close to the sea's surface and doesn't usually get bigger than 10 millimetres long.

Caption by / Photo by Christian Sardet/CNRS/Tara Expéditions

Marine ragworm Platynereis dumerilii isn't your ordinary ragworm. It's considered a living fossil, having survived for millions of years in the same environment, still with many of the same features as its ancestors.

This makes it a very good study case for evolution -- in particular its eyespots. Eyespots are the most primitive form of eyes, able only to detect the presence of light, which allows the worm to navigate. Everything else, it performs using touch. These eyespots, scientists theorise, are the nearest existing formation to the earliest evolution of eyes.

Caption by / Photo by Eric Roettinger/KahiKai/Tara Oceans
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