This siphon acts as a breathing tube...and a warning.
Emerging from the sediment is its owner, a six-inch-long toxic killer-the cone snail.
Snails are usually thought of slow, slimy and delicious in a garlic-butter sauce.
But with some 40,000 different species of snails, a few are bound to buck the system.
In the waters of Southeast Asia, this is the underwater version of a tank-with a hard spiral shell...flexible treads...and down in front-a cannon.
It has eyestalks on either side, but it hunts primarily by scent, using its siphon.
The target: a nearby fish.
The fish hides deeper under the rock rather than swimming away.
Bad idea. It still has room to move.
But inside this probing tube, called a proboscis, the cone snail has a long-range weapon-a harpoon.
Made of a modified tooth, the harpoon can be launched by a quick muscular contraction.
Fish-hunting snails are particularly dangerous, with venom strong enough to kill a human.
This harpoon is cocked and loaded. Target is within range.
The cone snail strikes.
The fish is paralyzed within seconds, reeled back in, and swallowed.
With a full belly, the cone snail returns under the sediment, its siphon peeking out as a reminder and a warning.