AMAZING
It's estimated that there's more than one million species in the ocean, but only about a quarter of them are known and have been scientifically described. With those huge numbers, and with the evolutionary process having started in the sea, it's little wonder that many marine creatures have weird and amazing capabilities. Here are just a few of the incredible facts. More will be added over time, but please send an email if there are hot contenders for the page.
SPERM WHALES - They can dive deeper than 600 metres, twice as deep as any human has managed. They have the biggest brains in the world and appear to make decisions together. They produce clicks called codas. Baby sperm whales, before they can click proficiently, babble. Sperm whales chatter all the time.
BLUEBOTTLES - Also known as the Portuguese Man'o War, these animals might look like one creature, but each one is actually made up of a colony of four different types of animals. Some form the float on top, some form the stinging tentacles, others perform digestion and the rest are for reproduction.
SHARKS - Sharks have what's called the Ampullae of Lorenzini, which are visible, gel-filled pores on and around their snouts. These are used for electroreception, meaning that sharks can detect electrical impulses. Sharks use this sense to 'hear' muscle contractions and even heart beats.
TURTLES - When injured sub-adult and adult turtles are being rehabilitated, each one can be taught to come to the surface for their specifically prepared meal with the use of differently coloured and patterened paddles dangled in the water . Called target training, it's amazing how each one knows their own paddle.
LIMPETS - They may seem cemented to rocky shores, but limpets are able to move and to grow and harvest their own food in the form of algae. They tend the algae around them and only eat what's needed in a systematic pattern, allowing time for the algae to grow back before they graze in a particular spot again.
SEA STARS- Also called starfish, these usually five-limbed animals can grow another limb if one is eaten or broken off. Sometimes they have more than five limbs; like any species, their genetics can go awry. And they should never be picked up because they have delicate, tiny tube feet underneath that help them to move.
SEA CUCUMBERS - First, they've got nothing to do with cucumbers other than being shaped like them. They can be just millimetres long to over six feet. But what they're renown for is breathing through their anuses. They pull water in through the anus and into respiratory trees. Hence the nickname 'butt breathers.'
SPONGES - They don't look like it, but these are animals and thought to have been of the first life in the sea. What's incredible is that a fair-sized sponge can filter more than 20,000 litres of water a day. They filter it for food, but as they do that they improve water quality by collecting bacteria and processing nutrients.
HAGFISH - They're creepy looking, but amazing. When touched they can almost instantly produce a bucketful of slime, and much more if need be. This deters predators and gets in the gills of fish, but the hagfish doesn't get trapped because it can tie its body in a knot and slide from head to tail, wiping off the slime.
MANDELA'S NUDIBRANCH - There's a nudibranch (pronounced noo dee brank) named for the late President Nelson Mandela. Nudibranchs are beautiful and multi-coloured sea slugs. What's special about this one, dedicated in 1999, is that unusually it's the only one of its genus, which was named Mandelia.
KELP - Kelp is a type of brown algae and one of the best-known species, the sea bamboo, can grow about 15 centimetres a day and be more than 12 metres long when mature. It's found from South Africa's west coast round to De Hoop. And its fronds produce slime so as to keep from being damaged in stormy weather.
UPRIGHT CODIUM - This seaweed is a green algae and can be found close to or on rocky shores. Because it's sometimes smothered in sand or just has the tips of its branching fronds poking above the sea's surface, the movement of its photosynthesising chloroplasts can be regulated so that the use of light is maximised.
SHORTFIN MAKO SHARK - This is the fastest shark in the sea. Sadly they're endangered because they've been hunted and overfished. But they can reach speeds of more than 70 kilometres an hour. That's faster than the speed limit in town. And they're not particularly agressive, scuba divers can dive with them quite easily.
RAGGED TOOTH SHARKS - They're found south of Durban at Aliwal Shoal in winter. In summer, pregnant females go north to Sodwana and up to Mozambique. When they're pregnant they tend not to eat and green algae grows on their teeth. In the uterus, the biggest embryos will eat the others for nutrition before birth.
HARD CORAL - These are actually animals. They're made up of vast colonies of polyps closely related to anenomes. In their tissues they have photosynthetic cells called zooxanthellae, forming a mutualistic relationship. But if the sea is too hot for too long, the corals expel the zoonxanthellae and die in a bleaching event.
DECORATER CRABS - The clowns of the sea, these crabs camouflage themselves by sticking seaweeds and bits of shell, anenomes, sponges and more to their carapaces, which is the upper shell. When the crab grows and moults, climbing out of its old exoskeleton, it can transfer its camouflage to its fresh carapace.
FEATHER STARS - These look like fern fronds swaying in the sea, but they're animals with little feet that can run pretty fast for their size. They're related to sea urchins, sea cucumbers, sea stars and brittle stars and below their filter-feeding arms, they have cirri, which are tendrils that can hold on to a substrate or 'walk.'
OCTOPUSES - There are many amazing facts about octopuses. They're part of the phylum Mollusca, which includes animals with shells, but the only hard part of an octopus is its beak. What's incredible is that if its small beak can fit through a tiny hole, then the whole octopus will be able to squeeze through.
CONE SHELLS - These are one of the very good reasons not to touch anything underwater. The shells are quite pretty, but inside there's a snail with a radula that can dart out and harpoon prey. There are many species, but some of them have a venom that's lethal for humans, even if it's just a small jab.
WHITE MUSSELS - They're not seen clinging to rocks with black mussels and that's because they live under the sand on the shore. While they're under there, they extend siphons to the surface for respiration and feeding. They have a muscular "foot" to burrow and they recycle nitrogen - a vital element for marine life.
MANTIS SHRIMP - They're cute, but they'll break your finger. A mantis shrimp's punch is of the strongest in the world. It's so fast and hard with its punch that it vaporises water. These animals also have what may be the most complex eyes of all animals and they can see wavelengths and light that humans can't.
“Underwater I hear the water coming to my body, I hear the sunlight penetrating the water.”
James Nestor, Deep: Freediving, Renegade Science, and What the Ocean Tells Us about Ourselves
James Nestor, Deep: Freediving, Renegade Science, and What the Ocean Tells Us about Ourselves