The deep-sea fish that hunts with a glowing lure
This deep-sea monster fishes with a glowing lure on its head — and the males fuse into its body forever.
Which one is REALLY true about the Anglerfish?
The short version
The deep-sea anglerfish dangles a glowing, bacteria-filled lure to draw prey into its needle-toothed mouth, and can swallow victims twice its size. The tiny male bites onto a female and permanently fuses to her body, dissolving into a sperm-supplying appendage.
Why it's so weird
- ✓The Anglerfish fishes with a glowing lure that grows right out of its own forehead.
- ✓The Anglerfish glows because the bulb on its lure is packed with living bacteria, dangled like bait.
- ✓The Anglerfish can swallow twice its own size by stretching its stomach.
- ✓The Anglerfish lures curious into the light, straight into a mouth full of long, needle-like teeth.
- ✓The Anglerfish ends up with a tiny male permanently fused into its body, dissolving into a sperm-supplying appendage.
You could line up about 1 of them along a 7-year-old!
The full story
Deep in the pitch-black ocean, this monster goes fishing with a glowing rod on its own head. Meet the anglerfish, one of the strangest predators in the entire deep sea. A long spine grows out of its forehead, tipped with a bulb full of glowing bacteria that it dangles like living bait. Curious prey swim toward the light, straight into a mouth full of long, needle-like teeth that snap shut in an instant. Its stomach can stretch so much that it swallows victims twice its own size. But the weirdest part is its love life. The male is tiny, and when he finally finds a female in the darkness, he bites onto her body and never lets go. His skin fuses to hers, his organs dissolve, and he becomes a permanent part of her, just supplying sperm for the rest of her life. Follow for more weird animal facts.
The glowing "fishing rod" on the anglerfish's head is really a stretched-out fin spine, and the bright bulb on its tip is packed with billions of tiny living bacteria. The fish can't make light on its own, so it grows these bacteria inside the bulb and feeds them; in return, a chemical reaction inside the bacteria combines with oxygen to give off a blue-green glow. A young anglerfish actually takes the bacteria in from the seawater around it. Its very stretchy stomach and loose jaw let it swallow prey bigger than itself, and the strange mate-fusing trick works because anglerfish lost part of the immune defense that would normally reject another fish's body.
📚 Source: Meet the Tiny Bacteria That Give Anglerfishes Their Spooky Glow — Smithsonian Ocean ↗Scientists sequenced the genomes of many deep-sea anglerfish species and found that the fusing species had lost key adaptive-immunity genes (such as aicda and rag). Without these genes a female's body cannot mount the normal rejection response, so it can accept a fused male.
📚 Source: Sea of love: Behind the unusual sexual parasitism of deep-water anglerfish — Yale News ↗Watch the 45-second version
Anglerfish gallery
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“The Anglerfish fishes with a glowing lure that grows right out of its own forehead.”
“The Anglerfish is the only known vertebrate on Earth with no red blood cells at all.”
“The Anglerfish glows because the bulb on its lure is packed with living bacteria, dangled like bait.”