Smallest migrant

Who

Copepods (subphylum Crustacea)

Where

Not Applicable

When

2010

Details

Copepods (subphylum Crustacea) are planktonic organisms measuring on average 1–2 mm (0.04–0.08 in) long, although some polar species might reach 1 cm (0.4 in) in length. Despite their tiny size, they are the principle diet of much of the oceans´ inhabitants – including whales. Copepods live predominantly at the bottom of the ocean to avoid predators, although make a nightly ascent to the surface to feed. This vertical migration is also considered the most massive migration.

Smallest double landlocked country

Who

Liechtenstein

Where

Liechtenstein

When

2010

Details

Double landlocked countries are defined as being completely surrounded only by other landlocked countries, which means two borders must be crossed in order to reach the sea. Liechtenstein is the smallest, with a population of just 35,000 and an area of 160 km2. Liechtenstein is surrounded by Switzerland and Austria.

World’s smallest nematodes

Who

Nematode 

Where

Not Applicable

When

2010

Details

The world’s smallest nematodes or round worms have no common names and live in marine sediments. They are only 80 µm long, which means that it would take 20-30 of these minuscule worms lying end to end to equal the thickness of a single average coin.

Smallest organism capable of independent reproduction and growth

Who

Mycoplasma genitalium

Where

Not Applicable

When

2010

Details

The smallest organism capable of independent reproduction and growth is Mycoplasma genitalium, a parasitic species of ultramicrobacterium that lives in the respiratory and genital tracts of primates. Its size is approximately 200-300 nanometres.

Smallest living organism

Who

Nanoarchaeum equitans

Where

Not Applicable

When

2002

Details

The smallest entity universally recognised to be a living organism (not everyone considers the slightly smaller nanobes to be alive) is Nanoarchaeum equitans. This minuscule microbe was only discovered in 2002, in a hydrothermal vent on the seafloor off the coast of Iceland, and its cells are only 400 nanometres across. In addition, its genome is only 490,885 nucleotide bases long, which makes it the smallest non-viral genome ever sequenced.