Black sea cucumber

When these sea cucumbers are disturbed, such as when they are attacked by a predator, they release a sticky, white, thread-like secretion from their anus called Cuvierian tubules. This is used as a defense mechanism against threats. They are the only poisonous species of sea cucumber.

Scientific Name
Holothuria leucospilota
Order: Aspidochirotida, Family: Holothuriidae
South of the Kii Peninsula, Indian Ocean, Pacific Ocean