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Jellyfish's 120-Foot Tentacles Shock Scientists
21 Mar
Summary
- A jellyfish discovered in 1865 held the record for the longest animal.
- Its tentacles stretched 120 feet, longer than any blue whale.
- Jellyfish are 94% water, making them metabolically cheap to build.
In 1865, a lion's mane jellyfish discovered in Massachusetts measured 7 feet across its bell and boasted tentacles of 120 feet, making it the longest animal ever recorded. This contrasts with the blue whale, which remains the heaviest animal. The lion's mane jellyfish's extraordinary length is a survival strategy, compensating for its weak propulsion.
This massive jellyfish, composed of 94% water and lacking bones or a centralized brain, has an incredibly low metabolic cost. Its mesoglea structure, mostly seawater, allows it to grow to remarkable sizes in nutrient-poor Arctic waters, though it also makes them fragile.
Recent research indicates that the widely held belief of increasing jellyfish blooms is contested. While populations have pulsed globally, a slight increase since the 1970s correlates with warming temperatures and overfishing. These conditions favor jellyfish, which are more tolerant than many other marine species.
