The Greenland Shark - World's Oldest Shark | 500+ Years Old Legendary Shark | Dr. Binocs Show

Summary

The script discusses the Greenland shark, the longest living vertebrate with a lifespan of 400 years. These sharks reveal their age not through rings on their vertebrae but through eye lens tissue samples. Reaching sexual maturity at 150 years, they grow slowly and have a sluggish metabolism. Despite moving slowly, Greenland sharks are potential apex predators, using circular motions to tear flesh from prey with their unique teeth. Facing vision issues from parasites and human hunting, urgent conservation is needed for these mysterious giants reaching 7,200 ft in extremely cold Arctic waters.

Takeaways

• 😲 The Greenland shark is the world's longest living vertebrate, with a lifespan of 400 years
• 🐢 These sharks grow very slowly, not reaching maturity until around 150 years old
• 🚤 Their bodies have antifreeze-like substances, allowing them to live in frigid Arctic waters
• 😴 They move very slowly, earning the name 'sleepy small head'
• 🦷 Unique teeth allow them to rip chunks of flesh off large prey
• 🥩 Their diet includes fish, squid, polar bears, horses and reindeer
• 🦠 A parasite attaches to their sides, damaging their vision
• 🌊 They can dive to depths of over 7,000 feet in pitch blackness
• 😷 Their flesh is toxic if consumed by humans
• ⏳ The oldest Greenland shark found was estimated to be about 390 years old

Q & A

How old is the oldest Greenland shark found?

The oldest Greenland shark was estimated to be 392 years old plus or minus about 20 years.

Why is the Greenland shark difficult to determine the age of?

Most sharks show their age through rings on their vertebrae, but Greenland sharks lack these rings. Instead, scientists determine their age by peeling layers of the lens in their eyes and through radiocarbon dating of lens tissues.

At what age do Greenland sharks reach sexual maturity?

Greenland sharks don't reach the baby making stage until they are around 150 years old.

Why is it difficult to determine the growth rate of Greenland sharks?

Figuring out how fast Greenland sharks grow is difficult since they are not often caught. One tagged shark grew only 2.3 inches over 16 years.

What enables Greenland sharks to live so long?

Researchers know very little about the Greenland shark's metabolism so it's unclear what enables their longevity.

How does the parasite Oomacta elongata affect Greenland sharks?

The parasite typically latches onto the shark's side, damaging the cornea and leaving scar tissue and infection, thereby affecting their vision.

How do Greenland sharks hunt without good vision?

Despite blindness, Greenland sharks depend on their other sharp senses adapted for the cold and dark ocean depths they inhabit.

Why is Greenland shark flesh toxic to humans?

While the reason is uncertain, consuming Greenland shark flesh can cause symptoms ranging from diarrhea to convulsions.

Why are urgent conservation efforts needed for Greenland sharks?

Humans have been hunting Greenland sharks for their liver oil, putting them on the verge of extinction.

What was the misconception about the oldest Greenland shark?

The oldest shark was estimated to be 392 years old, but there was a widely held but debunked claim that the oldest shark was 512 years old.