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
This story is from the November 2021 edition of BBC Focus - Science & Technology.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 8,500+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the November 2021 edition of BBC Focus - Science & Technology.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 8,500+ magazines and newspapers.
Already a subscriber? Sign In
5 SIMPLE WAYS TO RECLAIM YOUR ATTENTION
Primed for constant interruptions, your brain is now distracting itself, says science. It's time to break the cycle and retrain your focus
GOING ROGUE
Some planets are stuck following the same orbital paths their entire lives. Others break free to wander alone through the vast, empty darkness of interstellar space and there's a lot more of them than you might think
BED BUGS VS THE WORLD
When bloodthirsty bed bugs made headlines for infesting Paris Fashion Week in 2023, it shone a spotlight on a problem that's been making experts itch for decades: the arms race going on between bed bugs and humans. Now, with the 2024 Summer Olympics fast approaching, the stakes are higher than ever
THE EYES THAT WATCH THE SKY
When it launches in 2026, the Copernicus programme's Anthropogenic Carbon Dioxide Monitoring satellite will give us a new window on to Earth's atmosphere... And how we're altering it
TIME-RESTRICTED EATING LINKED TO HIGHER RISK OF CARDIOVASCULAR DEATH
Skipping breakfast might not be so good for your health, after all
INSIDE THE PROJECT TO SCAN THOUSANDS OF RARE SPECIMENS
A major collaborative project has created 3D reconstructions of previously locked away museum specimens
VIDEO IS FIRST EVIDENCE OF AN ORCA KILLING A GREAT WHITE
Tourists sailing off the South African coast film a never-before-seen event: a lone orca attacking a 2.5m shark
AI REVEALS PROSTATE CANCER IS NOT JUST ONE DISEASE
DNA analysis carried out by artificial intelligence has helped scientists make a discovery that could revolutionise future treatment
MYSTERIOUS WAVES DETECTED IN JUPITER'S CORE
Scientists hope unusual fluctuations in the gas giant's magnetic field might reveal what's inside
MINI ORGANS GROWN FROM UNBORN BABIES MARK A BREAKTHROUGH IN PRENATAL MEDICINE
A new technique could allow congenital conditions to be diagnosed and treated before birth