BEAUTIFUL BUT DEADLY
Famous for being some of the world's deadliest animals, blueringed octopuses are usually quite docile and spend most of their time hiding in rubble and shells. There are between 4 and 10 species in the Hapalochlaena genus, living in shallow seas from Australia to Japan. They are all less than a handspan in size, and each has around 60 bright blue rings which flash as a warning when the octopus feels threatened. The rings contain multilayer reflectors, arranged to reflect blue-green light. The flashing is controlled by muscles that pinch in a surrounding layer of black pigmented chromatophore cells that cover the blue iridescence. When the muscles relax the blue iridescence is exposed. The warning flashes come before the octopus deploys its deadly defensive bite. Bacteria living in their salivary glands make tetrodotoxin, TTX, the same toxin that makes pufferfish deadly to eat. Female blue-ringed octopuses cover their eggs in TTX to protect them from getting eaten.
SPECTACULARLY SEE-THROUGH
Denne historien er fra November 2021-utgaven av BBC Focus - Science & Technology.
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Denne historien er fra November 2021-utgaven av BBC Focus - Science & Technology.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
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COULD MARINE CLOUD BRIGHTENING HELP US FIGHT CLIMATE CHANGE?
The theory behind marine cloud brightening is that brighter or whiter clouds reflect more sunlight back into space.
IS IT SAFE TO RUN EVERY DAY, OR SHOULD I DITCH MY RUN STREAK TO SAVE MY KNEES?
A running streak, where you run every day without taking rest days, can be highly motivating and beneficial for overall fitness. Running is great cardiovascular exercise and isn't to be discouraged (and finding a routine with some consistency is great). Getting a bit of exercise as often as possible is also hugely beneficial for your mental health.
WHAT MAKES THE MEDITERRANEAN DIET SO GOOD FOR US?
The Mediterranean diet may help you live longer, especially if you also adopt the lifestyle of people living near the Med during the 1950s.
WHAT IS MEXICO'S BLUE HOLE?
The world's deepest blue hole (marine sinkhole) lies off the coast of Mexico's Yucatán Peninsula. It's at least 420m (1,378ft) deep, but explorers still haven't found its bottom.
HOW CAN I TELL IF I'VE GOT HIGH CORTISOL LEVELS?
Cortisol is a hormone produced by glands in our bodies called the adrenal glands, which sit above the kidneys. It plays a critical role in various bodily functions, including regulating metabolism, reducing inflammation and helping the body respond to stress. While essential for our health, chronic elevation of cortisol levels can lead to several issues.
THE LUNGFISH
In 1836, European scientists discovered a peculiar animal from the River Amazon that they struggled to identify. Its eel-like body was a few feet long and its air-filled lungs persuaded anatomists it must be a reptile.
ARE WE THE ONLY SPECIES TO HAVE BEEN THROUGH A STONE AGE?
The Stone Age might conjure up images of early humans, sitting around a campfire or hunting prehistoric beasts, but evidence shows that we're not the only species that has learned how to work with stone tools. Wild chimpanzees (Pan troglodytes) use stone tools to crack open nuts.
Should we scrap daylight saving time?
Most of us look forward to the extra hour we get in bed every October, but researchers argue that changing the clocks twice a year harms our health
THE INTERNET OF ANIMALS
SCIENTISTS ARE USING ELECTRONIC TAGS AND SATELLITES TO TRACK WILD ANIMALS AND CREATE A DATA NETWORK THAT COULD HELP US ADDRESS THE BIODIVERSITY CRISIS
MUSIC FOR A DISTRACTED GENERATION
The number of things competing for our attention is often overwhelming. Can dreamy soundscapes created with neuroscience help our bewildered brains to concentrate?
