How does a jellyfish sting? - Neosha S Kashef | Summary and Q&A

TL;DR

Jellyfish stings are caused by nematocysts shooting venom through harpoons upon stimulation, with various species and predators involved.

Key Insights

• 🪆 Jellyfish stings are caused by nematocysts, specialized stinging cells containing venom.
• 🪼 Different jellyfish species have varying sting abilities and venom toxicity.
• 🐢 Predators like turtles and sunfish have adaptations to consume jellyfish despite their stings.
• 🪼 Some organisms, like nudibranchs and fish, utilize jellyfish defenses for their protection.
• 😷 Scientists are exploring using jellyfish venom for medical applications.
• 💦 Proper treatment for jellyfish stings involves avoiding fresh water and using vinegar or seawater.
• 🪼 Indo-Pacific box jellyfish can pose a deadly threat due to the toxicity of their venom.

Transcript

You're swimming in the ocean when something brushes your leg. When the tingling sets in, you realize you've been stung by a jellyfish. How do these beautiful, gelatinous creatures pack such a painful punch? Jellyfish are soft because they are 95% water and are mostly made of a translucent gel-like substance called mesoglea. With such delicate bo... Read More

Questions & Answers

Q: How do jellyfish sting humans?

Jellyfish sting humans through nematocysts, specialized stinging cells that shoot venomous harpoons upon stimulation, causing pain and irritation.

Q: Can all jellyfish species sting?

Yes, all jellyfish species possess cnidocytes with nematocysts, allowing them to sting for defense or prey capture, although the severity of the sting varies.

Q: How do predators like turtles and sunfish deal with jellyfish stings?

Predators like leatherback turtles and ocean sunfish have adaptations to prevent jellyfish from escaping after engulfing, using spines and teeth to handle the stings.

Q: In what ways are humans exploring the potential of jellyfish venom?

Scientists are researching using jellyfish venom for medical purposes, with potential applications in drug delivery due to the unique properties of nematocysts.

Summary

Jellyfish are soft creatures made mostly of water. They rely on venom-containing stinging cells called cnidocytes for protection and prey capture. Tentacles, which can be extremely long in some species, contain the majority of the stinging cells. These cells use a whip-like hollow tubule to inject venom into their victims. Jellyfish stings can be painful, and certain species can even be deadly. However, jellyfish have their own predators and some organisms have found ways to benefit from their stinging abilities.

Questions & Answers

Q: Why are jellyfish soft?

Jellyfish are soft because they are 95% water and mostly made of a translucent gel-like substance called mesoglea.

Q: How do jellyfish protect themselves?

Jellyfish rely on thousands of venom-containing stinging cells called cnidocytes for protection. These cells can inject venom into their prey or potential threats.

Q: Can baby jellyfish sting?

Yes, even baby jellyfish, as small as a pencil eraser, have the ability to sting.

Q: How does a jellyfish develop from a larva?

Larval jellyfish, called ephyrae, start as tiny flowers pulsating in the sea. As they grow, they become umbrella-shaped with a bell at the top and descending tentacles around the margin.

Q: How long can a jellyfish's tentacles be?

The largest species of jellyfish, like the lion's mane, can have tentacles that extend more than 100 feet, longer than a blue whale.

Q: How does a jellyfish sting its victim?

The venom is ejected through a nematocyst, a whip-like hollow tubule, which lies coiled under high osmotic pressure. When triggered, the nematocyst shoots out, injects venom, and can penetrate the victim.

Q: Can a jellyfish's tentacles continue to sting after the jellyfish has died?

Yes, nematocysts can continue to fire even after a jellyfish has died, so it's important to remove lingering tentacles stuck to the skin.

Q: How can nematocysts be inactivated?

Rinsing with vinegar usually renders undischarged nematocysts inactive. Seawater can also help remove residual nematocysts. However, using fresh water is not recommended as it may trigger the nematocysts to fire.

Q: Are all jellyfish stings painful?

Most jellyfish stings are a painful nuisance, but some can be deadly. The Indo-Pacific box jelly, also called a sea wasp, releases venom that can cause contraction of the heart muscles and rapid death in large doses.

Q: Are there any predators that can consume jellyfish?

Yes, leatherback turtles and ocean sunfish are thick-skinned predators that can consume jellyfish. They have adaptations such as backward pointing spines or recurved teeth to prevent the jellyfish from escaping.

Q: Do other organisms benefit from jellyfish stinging abilities?

Yes, small lobster slipper larvae can cling to the bell of a jellyfish and feed on the jelly while conserving their own energy for growth. Some small fish also use jellies as moving reefs for protection, darting between tentacles without touching them. Nudibranchs, sea slugs covered in protective slime, can eat cnidocytes and transfer them to specialized sacks for later use as weapons against their own predators.

Q: How are scientists exploring the potential benefits of jellyfish stings?

Scientists are working on manipulating cnidocytes to deliver medicine, with nematocysts being just about 3% of the size of a typical syringe needle. This could lead to the development of new drug delivery methods.

Takeaways

Jellyfish are fascinating creatures that use venom-containing stinging cells called cnidocytes for protection and capturing prey. Their tentacles, which can have an incredible length, house most of these stinging cells. While jellyfish stings can be painful and even deadly, jellyfish are not invincible. They have predators that have adaptations to consume them or use them for their own benefits. Additionally, scientists are exploring ways to harness the stinging abilities of jellyfish for potential medical applications.

Summary & Key Takeaways

• Jellyfish, composed mostly of water, use venom-containing stinging cells called cnidocytes for protection and prey capture.

• Nematocysts, triggered by stimuli, shoot harpoon-like structures with venom in less than a millionth of a second.

• Various predators have adaptations to feed on jellyfish, while some organisms, like nudibranchs, use jellyfish's defenses for their own protection.