50 Fun Facts About Plankton

The word 'plankton' comes from a Greek word meaning what?

Plankton are defined by their inability to swim against currents, not by what species they are.

What is a single individual plankton organism called?

And the study of plankton is planktology.

Which German marine biologist coined the word 'plankton' in 1887?

He shortened 'halyplankton', from the Greek for 'sea' and 'I drift', and founded quantitative biological oceanography.

Organisms such as fish and squid that can swim against currents, unlike plankton, are called what?

Bottom-dwellers are the benthos.

Roughly what share of Earth's oxygen production comes from phytoplankton?

They do this despite making up only about 1% of global plant biomass.

Photosynthesising plankton are phytoplankton. What are the animal-like consumers called?

A third group does both, and a fourth are decomposers such as fungi, bacteria and viruses.

What are plankton that are planktonic only as larvae called?

Sea urchin, starfish, crab and most fish larvae fall into this group before settling or swimming off.

What are the drifting organisms of the atmosphere, such as spores and pollen, called?

They rain hundreds of millions of viruses and tens of millions of bacteria on every square metre of the planet daily.

What is the shower of organic detritus that sinks from the sunlit ocean to feed deep-sea life called?

The term was coined by explorer William Beebe, watching from his bathysphere.

Marine viruses are estimated to kill what proportion of ocean microplankton biomass every day?

They are the main agents that wipe out harmful algal blooms.

Which micronutrient is missing in the ocean's 'HNLC' regions?

It arrives mostly as dust, which is why the eastern Atlantic downwind of the Sahara teems with phytoplankton.

Diatoms are encased in a cell wall made of what?

The glassy frustule produces structural colours that earned them the names 'jewels of the sea' and 'living opals'.

Diatoms are estimated to generate what share of the oxygen produced on the planet each year?

They also draw more than 6.7 billion tonnes of silicon a year out of the water they live in.

Fossilised diatom shells form a soft rock used in cat litter, toothpaste and to stabilise what explosive?

Alfred Nobel patented the nitroglycerine-and-kieselguhr mixture in 1867.

Dinoflagellates take their name from Greek and Latin words meaning what?

They carry two flagella and can bloom into red tides or glow blue-green in the dark.

A 'red tide' is a harmful bloom of which kind of plankton?

Eating shellfish contaminated by such blooms can cause poisoning; Karenia brevis is the Florida culprit.

Which glowing organism, whose name means 'light at night', makes seawater glow bright blue after dark?

Ernst Haeckel moved it out of the jellyfish and in with the dinoflagellates in 1873.

Coccolithophores cover themselves in plates made of what?

They are the most productive calcifying organisms on the planet; their coccoliths are essentially chalk.

Which coccolithophore, the most abundant in modern oceans, forms milky blooms visible from space?

Now often called Gephyrocapsa huxleyi, it blooms in nutrient-poor water after the summer thermocline forms.

Copepods, the tiny crustaceans of the plankton, typically have how many eyes?

Most have a single, usually bright red, compound eye in the middle of a transparent head, and no heart.

Roughly how many species of copepod are known?

About 2,800 of them live in fresh water; most are only 1-2 mm long.

The word 'krill' comes from which language, where it means 'small fry of fish'?

Krill are shrimp-like crustaceans that filter phytoplankton and feed whales, seals and penguins.

Antarctic krill has a total biomass of roughly how much?

Whales, seals, birds, squid and fish together eat between 152 and 313 million tonnes of it a year.

Antarctic krill swarms can reach densities of how many animals per cubic metre?

Their 12-hour vertical migrations help mix nutrient-rich deep water up to the surface.

Which cyanobacterium, found in 1986, is probably Earth's most abundant and smallest photosynthetic organism?

Its discoverer Sallie Chisholm won the 2019 Crafoord Prize; it is a major producer of the ocean's oxygen.

Which bacterium, perhaps Earth's most abundant, makes up a third of surface-ocean microbes?

It is unusually small and busy recycling nutrients in the microbial loop.

What is the name for the daily rise and fall of drifting animals, the largest synchronous movement on Earth?

Some plankton swim hundreds of metres up and down in a single day.

What is the plankton-driven ocean process that carries carbon from the atmosphere to the deep sea called?

Marine microbes make up the great majority of ocean biomass.

In the 'viral shunt', viruses do what to bacteria in the plankton?

This keeps nutrients in the microbial loop instead of passing them up to grazers and fish.

Foraminifera, or 'forams', are single-celled plankton whose Latin name means what?

They build shells called tests, some with many elaborate chambers.

How big are radiolarians, the single-celled plankton famed for their intricate mineral skeletons?

Their elaborate glassy skeletons enclose a central capsule dividing the cell into inner and outer parts.

What is a salp?

Solitary salps reproduce by budding chains of tens to hundreds of clones.

The planktonic snails known as 'sea butterflies' and 'sea angels' belong to which group?

Sea butterflies have shells and sea angels do not; the split was made in 1810.

The eggs and larvae of fish drifting in the plankton are collectively called what?

Fish eggs cannot swim at all, so they are unambiguously planktonic.

The Continuous Plankton Recorder, running since 1931, catches plankton on what material?

Sir Alister Hardy's torpedo-shaped device has used the same 270-micrometre silk since 1948.

Which is the largest fish in the sea, a filter-feeder that lives mainly on plankton?

It also hoovers up krill, fish eggs and small schooling fish such as sardines.

Bright green blooms in lakes are usually caused by which organisms, popularly called blue-green algae?

Microcystis, for example, produces toxins; freshwater blooms are fed by excess phosphates.

What is the group of plankton that can both photosynthesise and eat called?

Some coccolithophores and whip-tailed protists once filed under phytoplankton are now placed here.

Marine microorganisms are estimated to make up what share of total ocean biomass?

Together they form the marine microbiome and drive nearly all photosynthesis in the sea.

Airborne marine microbes in sea-spray aerosols can stay suspended in the atmosphere for about how long?

They can travel hundreds of kilometres and remain viable if humidity stays above 70%.

What are organisms floating on or just below the sea surface, a subgroup of plankton, called?

Those on the surface film are epineuston; those in the top few centimetres are hyponeuston.

The smallest known photosynthetic organism, a marine bacterium, measures roughly how much across?

This picoplankter, found in 1986, is also probably the most abundant photosynthesiser on Earth.

Which fungi-driven process transfers nutrients from large inedible phytoplankton to grazers via parasites?

Parasitic chytrids do the work; the microbial loop and viral shunt are the bacterial and viral equivalents.

The tiny drifters were only discovered to include huge numbers of nano- and picoplankton in which decade?

They are now thought to make up the largest share of plankton by number and diversity.

Sheldon J. Plankton, the tiny green villain of SpongeBob SquarePants, owns which failing restaurant?

He spends his life trying to steal the Krabby Patty formula from his former best friend Mr. Krabs.

In SpongeBob SquarePants, what is Plankton's wife Karen?

Creator Stephen Hillenburg named her after his own wife, Karen.

Who voices Plankton in SpongeBob SquarePants?

Jill Talley voices Karen; the pair started as minor characters before Lawrence built them into the main antagonists.

Where did researchers in 2025 find a sharp rise in microbial diversity they named the 'prokaryotic phylocline'?

Samples were taken along the full water column from Easter Island to Antarctica.

Which wind-driven circulation pattern, named for a physicist, affects the local distribution of plankton?

Light is the primary driver of plankton distribution and nutrients the second.

Diatoms are estimated to be responsible for roughly what share of photosynthesis in the global oceans?

They bloom massively every spring and autumn.