Showing posts with label Amazing Fish. Show all posts
Showing posts with label Amazing Fish. Show all posts

Wednesday, October 27, 2010

Video of Cuttlefish Hunting

I mentioned in my earlier post that cuttlefish not only use their camouflage to hide, but also to confuse their prey. I finally found a good video of a cuttlefish trying to do this. This is a great example of how quickly the skin of a cuttlefish can change colors too.



In this case its prey is actually a plastic toy put there by a scuba diver, so it's attempts to confuse it don't seem to get much of a response. The only one confused here is the cuttlefish. The next video shows a cuttlefish hunting real fish.



When the diver gets too close, the cuttlefish suddenly switches from hunting prey to camouflaging from what he sees as a predator.

Monday, January 25, 2010

Cuttlefish

Cuttlefish have some of the most incredible camouflage of anything in the animal kingdom. Their highly complex brain allows them to control the cells in their skin to blend in perfectly with their surroundings, or flash colorful displays much like an LED billboard.

The cells on the skin of a cuttlefish are covered in tiny dots of all colors, much like the tiny dots that make up the screen of your computer. A cuttlefish can make their cells grow or shrink to bring out the perfect blend of colors to match whatever is around it.



Its skin can also change shape from its usual smooth texture to whatever matches its surroundings. When it combines its color and texture adaptation, a cuttlefish can become nearly invisible even in plain sight. Because it can change its camouflage almost instantly, cuttlefish are very good at stalking prey, or avoiding becoming a meal themselves.

Cuttlefish are excellent predators, feeding on small fish and crustaceans. They will sneak up on their prey until they are close enough to strike, then shoot out two of their longest tentacles like harpoons to grab onto their prey with their suction cups. Then they reel their victim back into their mouth. Cuttlefish will also sometimes flash waving patterns of bright colors to confuse their prey while they move in for the kill.

Cuttlefish are not actually fish as their name implies. They are mollusks, close relatives of octopus and squid. Unlike their boneless cousins, cuttlefish have an internal shell which acts a skeleton to help them hold their shape. Cuttlefish shells are often sold at pet stores as calcium supplements for birds.

Cuttlefish use their skin for more than just camouflage. They can also use their amazing control of color to communicate. They often change to bright colors when they are angry to warn other sea creatures or other cuttlefish to stay away. They also use their arms to communicate, holding them in certain positions as if they are using sign language.

I once found a cuttlefish while I was snorkeling in Cozumel. Unlike most marine life, it seemed genuinely curious about me. I swam in close and moved my fingers into the position it had its tentacles in. It waved its arms back and flashed bright colors at me as if it was trying to carry on a conversation. After a few minutes, the cuttlefish darted away and disappeared. I still wonder if I said something mean or just wasn't much fun to talk to.



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.



Sunday, April 5, 2009

Frogfish



Frogfish are some of the most bizarre looking fish in the ocean. They are a type of angler fish with amazing adaptations for camouflage. Their bodies are oddly shaped and they can change colors to blend in with their environment. Most frogfish mimic corals, sponges, seaweed, or rocks. This camouflage keeps predators from identifying them as food, and it keeps their food from identifying them as predators.


Frogfish spend most of their lives scooting along the bottom of the ocean. They lie motionless, resting on specially modified fins that act almost like legs.

Like most angler fish, frogfish have a very clever method of hunting prey. Instead of going out to find their food, they bring their food to them. Frogfish have a small growth on their heads that looks like a small worm or fish. They dangle this lure in front of their mouth, tricking other fish into thinking it is food.


The fish come close, thinking they will eat an easy meal. Instead they become the meal for the frogfish.


Frogfish are found in oceans throughout the world, and they take on a staggering variety of shapes and colors.


Thursday, January 29, 2009

Manta Rays

Manta rays are the largest member of the ray family, growing up to 25 feet across. While most fish swim, rays fly gracefully through the water by flapping the edges of their fins like wings. Rays are actually relatives of sharks.

Manta rays are a favorite among divers because they are so large and beautiful, but also very gentle. They are said to often become curious about divers and interact with them. They have the largest brain-to-body ratio of any of the shark family. They are also sometimes found in groups or even large schools.

Manta rays are sometimes referred to as devil rays because of the hornlike projections around their mouths. These are actually used to funnel food into their gaping mouths. They feed exclusively on plankton, which they scoop into their mouths as they glide along the currents. Manta rays swim slowly, often doing loops and dives as they seek out plankton.

With their huge wingspan, one often wonders if they could fly. In some ways, they do. Rays have been observed leaping completely out of the water for short periods of time. Naturally gravity takes its toll but they get some considerable air time before plunging back under the waves.

If you want to see a giant manta ray in person, you can find one swimming along with 3 whale sharks in the Georgia Aquarium. I got to watch this graceful giant up close on my recent visit there.

Monday, October 27, 2008

Puffer Fish

Puffer fish have a very unique defense mechanism. They are able to swallow water to inflate their bodies like balloons. Most fish will eat anything that will fit into their mouth, and avoid anything bigger than themselves. By puffing up like this, a puffer fish quickly jumps to a much bigger size, and becomes inedible to most fish.

A puffer fish spends most of its time deflated. In this state, it is much more streamlined and can swim unhindered in search of food. When it puffs up, it moves extremely slowly. I used to catch puffer fish by startling them into puffing up. This made them suddenly almost immobile. I could then easily pick the little ball up with my hands.

If I caught them in a net before they managed to puff up with water, they would fill up with air. This turned them into little living balloons. I would put them on the surface and they would float down the beach until they relaxed and deflated.

Puffer fish come in many colors, shapes, and sizes. Most can easily fit into the palm of your hand, but some grow as big as a person. Some species are decorated with beautiful colors as well.

Monday, October 20, 2008

Mandarin Goby

One of my favorite fish in the whole ocean is the Mandarin Goby. Its lifestyle and behavior are much like any other goby, but its colors are absolutely stunning.

These vibrant and flashy fish can be found as the centerpiece of many saltwater aquariums. They are heavily sought after because of their beautiful display.


Friday, October 10, 2008

Flying Fish

Flying fish are some of the most amazing organisms in the ocean, and believe me there are lots of amazing creatures in the sea. Flying fish have a very unique defense mechanism for escaping predators. They have found that the best way to avoid other fish in the water is to get out of the water. As their name suggests, flying fish can actually leap out of the water and fly short distances.

Flying fish have very specialized pectoral fins (the fins on their sides) which can actually function as wings. While underwater, they fold the fins close to their bodies so they can swim just like normal fish. When a flying fish feels threatened, it will take a running start and jump out of the water.
Some flying fish have been clocked to fly for over 45 seconds, but most flights are relatively short. Like all fish, flying fish still breathe through gills, and must return to water before they run out of oxygen. Still, that quick flight is plenty of time to escape most predators. As far as most fish are concerned, if their prey leaves the water, it is out of reach.