Echinoderms
Silo of starfish, sea urchins and sea cucumbers.
Sea cucumber
Holothuria sp.
Sea cucumber
A true vacuum cleaner of the seafloor, continuously recycling sand and sediment — some species defend themselves by expelling their own internal organs at an attacker.
🌊 0–1000 m
- ⚡ Can expel its own internal organs to repel a predator, then regenerate them entirely
- ⚡ Recycles a considerable amount of marine sediment every year, an essential ecological role
Crown-of-thorns starfish
Acanthaster planci
Crown-of-thorns starfish
Able to devour an entire coral reef within months during massive outbreaks, it is also one of the few starfish with genuinely venomous spines.
🌊 0–30 m
- ⚡ Can regenerate a whole individual from a fragment of its body
- ⚡ Can devour an entire coral reef within months during a massive outbreak
Sunflower sea star
Pycnopodia helianthoides
Sunflower sea star
One of the largest starfish in the world, able to move surprisingly fast thanks to more than 15,000 tube feet, but today decimated by over 90% by a mysterious disease.
🌊 0–120 m
- ⚡ Can have up to 24 arms and more than 15,000 tube feet
- ⚡ One of the fastest starfish known, over a metre per minute
Diadem sea urchin
Diadema setosum
Diadem sea urchin
Its long, thin black spines, able to break off and remain lodged in the skin, make it one of the sea urchins divers fear most, despite its essential ecological role.
🌊 0–40 m
- ⚡ Its entire body is light-sensitive, acting like one giant, distributed eye
- ⚡ Plays an essential role in controlling algae populations on coral reefs