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.

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.

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.

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.

Sea Snakes

Sea Snakes are some of the many land animals that have adapted to live in the ocean. They seem completely out of place, yet these unusual marine reptiles are perfectly adapted for life below the waves. I'm sure it is hard to picture a snake under water, so I posted the video below of a sea snake gliding across a reef. It seems just as natural swimming underwater as it would slithering on dry land.



There are over 60 different species of sea snakes found in tropical seas throughout the world. Most are brightly colored, and nearly all sea snakes have a flattened tail that works as a paddle. Unlike their terrestrial cousins, many species of sea snakes lack the ability to crawl on land. Others are known to spend a good amount of time out of the water. Sea snakes may live underwater for most of their lives, but they still breathe air like all other reptiles.

The forked tongue of a sea snake is specially adapted to allow them to smell underwater. They cruise along coral reefs hunting fish, eels, shrimp, or even fish eggs depending on the species.

Most sea snakes are highly venomous and pack deadly poison, but few are known to be aggressive towards humans. Attacks are not very frequent, and they rarely deliver much poison when they strike. When sea snakes are handled by humans or caught on land, they can be very dangerous. As with most sea creatures, it is best to look but don't touch.

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.

Cone Snail Videos

I was happy to see how much attention the post on Cone Snails has gotten. I understand it is hard to picture a snail killing something, so I dug up a couple of videos of these slow but deadly predators on the hunt. It's somewhat disturbing and totally amazing to see these Cone Snails in action.

This is a very good clip from National Geographic showing the full process of a Cone Snail hunting.



And this video from Nature shows how quickly a Cone Snail can subdue a live and very active fish.



One of the reader responses to my previous Cone Snail post asked where Cone Snails can be located. I found a map from National Geographic showing just this.

It's small but you can see the regions where Cone Snails can be found highlighted in yellow. They are mostly located in tropical oceans. Florida is the only place in America that I know of where you can find Cone Snails. Still, if you think you might have found a cone snail, just remember the general rule of the ocean:
When in doubt, don't touch it.

Cone Snails: Deadly Predators

Oddly enough one of the most deadly animals in the entire ocean is a tiny snail called a cone snail. While it seems comical to even think of a snail as dangerous, let alone lethal, cone snails have some of the most sophisticated and deadly neurotoxins known to man. A cone snail sting can kill a person within minutes of injection.

While most snails simply graze on algae, cone snails are active predators. They are fully capable of catching and eating quick and agile fish. These mollusks move just as slowly as other snails, but they pack a hidden weapon. They have a long tube which conceals a deadly harpoon tipped with their powerful venom. They can fire this harpoon with lightning fast accuracy. Their prey is killed almost before even knowing it has been hit. The snail then reels the dead fish into its vacuum-like mouth and swallows it whole.

People are rarely attacked by cone-snails because they do not actively hunt humans. Only about 15 known cone snail related deaths have been reported to date. Most of these incidents occur because people pick up the beautiful shells they see on the ocean floor. When the snail is agitated, it fires its harpoon, and the person often dies within minutes. If you ever see a cone-shaped shell lying on the sand, it's best to just leave it alone.

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.

Jellyfish

Jellyfish are cnidarians, related to sea anemones and sea slugs. They consist of a dome-shaped body and tentacles that trail behind them. Jellyfish are able to swim through the water by pulsing their jelly-like bodies. Their tentacles are covered in poisonous stinging cells called nematocysts. These tentacles can paralyze or kill fish. Some jellyfish, like the box jellyfish below, are powerful enough to kill humans. The venom in a box jellyfish can stop a person's heart in less than 3 minutes.

While most jellyfish are relatively small, some can grow to enormous sizes.

During certain times of year, jellyfish can be found in huge numbers, clouding the seas with their pulsating forms.

Some jellyfish can even glow in the dark.

Crabs

Crabs are Crustaceans and members of the Arthropod phylum. They have a hard exoskeleton surrounding their entire bodies which acts as a suit of armor. Most crabs use their powerful claws to fend off attacks and capture prey.

Some species such as the hermit crab scoot into empty snail shells and carry the shell on their backs. When threatened, they can disappear into the shell.

Other species rely on camouflage to hide from predators.

Most species of crabs can survive for short periods of time outside the water. Their shells hold enough water to keep their gills moist, therefore allowing them to breathe on land. Some crabs spend most of their lives on land.

Crabs range in size from barely visible to the giant coconut crab pictured here. Crabs can be found all over the world in a staggering variety of shapes and colors.