Greenland shark
Somniosus microcephalusA slow giant of cold, deep water. Dating of eye-lens tissue suggests it can live for centuries, longer than any other known vertebrate.
Deep waterArctic and North AtlanticLife in the Atlantic,
one fathom at a time.
A small notebook about the animals of the second-largest ocean: who lives where, how deep, and what makes each of them odd enough to remember.
Meet the creaturesAn ocean shaped like an S
The Atlantic runs from the Arctic to the Southern Ocean, split down the middle by the longest mountain range on Earth. Cold currents and warm ones meet along its edges, and that mixing is why some of its waters are among the most productive anywhere.
These pages are a reader's notes, not a field guide. Each entry sticks to a few things that are well established and worth knowing.
- ~20%of Earth's surface is covered by the Atlantic
- ~3,600 maverage depth
- ~8,400 mdeepest point, in the Puerto Rico Trench
- 16,000 kmapproximate length of the Mid-Atlantic Ridge
Three to start with
Portuguese man o' war
Physalia physalisNot a jellyfish and not one animal. It is a colony of specialised units that drifts under a gas-filled float and sails with the wind.
SurfaceStingsAtlantic horseshoe crab
Limulus polyphemusCloser to spiders than to crabs, with a body plan that has changed little in hundreds of millions of years.
ShallowsWestern Atlantic