Showing posts with label Symbiotic Relationships. Show all posts
Showing posts with label Symbiotic Relationships. Show all posts

Monday, April 27, 2009

Pistol Shrimp


Pistol Shrimps are tiny creatures with a deadly weapon. They are capable of shooting supersonic blasts from their fingertips with enough force to instantly stun or kill their prey.



You may notice that one claw of a pistol shrimp is much larger than the other, and very strangely shaped. This claw serves as both its lethal weapon, and its voice. This claw can be forcefully snapped shut, shooting a jet of water out at such a high speed that it actually vaporizes the water. This causes a small air bubble to form. The bubble collapses with enough force to send concussive shockwaves capable of stunning and incapacitating prey.

A pistol shrimp will lie in wait under a rock or in a burrow until food comes along. When it is in range, the shrimp will forcefully snap its oversize claw shut, shooting out sonic waves that incapacitate its prey. The helpless victim is dragged unconscious into the burrow and eaten by the pistol shrimp.

Another unusual thing about pistol shrimps is that they often allow a fish to live with them. Certain kinds of goby fish often share burrows with pistol shrimp. The fish serves as a guard dog, protecting the shrimp from bigger predators. In return, the pistol shrimp works hard to keep the burrow clean and excavate their home.


The loud blast created by a pistol shrimp's claw can be heard from great distances. Because of this, they also use their claw for communicating with other pistol shrimps. When you listen underwater you may hear a lot of popping sounds. Some of them may be made by pistol shrimps firing off their sound waves to communicate with each other.



Monday, October 6, 2008

Sea Anemones

Sea anemones resemble flowers, but they are actually cnidarians, related to coral and jellyfish. They spend their lives rooted to surfaces using a big sticky foot. Their tentacles wave in the currents and catch any pieces of food or animals that pass by.

Sea anemones spend their larval stage as zooplankton floating in the currents. When they reach maturity, they settle on the sea bottom and anchor themselves.

The tentacles of a sea anemone are lined with tiny cells called nematocysts. These cells contain a microscopic spring loaded harpoon. When an unfortunate animal brushes by, the harpoon fires, ensnaring the victim and delivering deadly poison. Once the hapless victim is entangled, the anemone pulls it into its mouth. It digests the food in its stomach and excretes the waste back out through its mouth.
Sea anemones are often sought out as partners for other organisms which use their powerful poison as defense. Hermit crabs will often uproot small sea anemones and stick them on their backs. This serves the anemone well because it is now mobile and can more easily catch bits of food. It also gets to snack on any of the crab's leftovers. The crab benefits by having added protection from predators. Anything trying to eat the crab gets a powerful sting.

Another animal that uses the sea anemone as protection is the clown fish. These fish are adapted to keep the sea anemone from stinging them, and spend their entire lives nestled safely in their deadly tentacles.

Sea anemones come in many shapes, sizes, and colors, and can be found throughout the world, from the cold oceans of North America to tropical Australian coral reefs.