Sea Creatures Pictures

The ocean is full of a wide variety of creatures.  We are providing you with a glimpse of the ocean today with information and pictures of the jellyfish, octopus, deep sea fish, sea snakes, and sharks.

Jellyfish

     Jellyfish are from the phylum Cnidaria and are free-swimming.  They can be found in every ocean, and some species are even found in freshwater.  There are over a thousand species of jellyfish.  Jellyfish are not really fish.  Jellyfish do not have a respiratory system.  They also do not have complete control over their movement through the ocean.  The jellyfish is made primarily of water, and their umbrella mass is composed of a material that is gelatinous, and it is called mesoglea.  At times jellyfish can be seen in blooms of hundreds or thousands of jellyfish in one area.  This is normally a seasonal event and common when there is warm sunshine.  Jellyfish are their own worst enemy as other species of jellyfish are usually their worst predators, but other predators of the jellyfish include tuna, sea turtles, shark, swordfish, and salmon.  Jellyfish typically will live anywhere between a few hours to several months.  Some jellyfish are harvested for food.  They are commonly eaten in China and Japan in different forms.  Jellyfish will sting their prey.  They will accomplish this task through their nematocysts.  It is unusual that it causes severe reactions, but in the case of severe reactions, immediate medical care is necessary. 

Octopus

      The octopus makes its home in many different regions of oceans around the world, but they are commonly found in coral reefs.  There are about 300 species of octopus.  The octopus is characterized by its eight arms which trail behind it as it swims through the ocean.  Most octopuses don't have an external or internal skeleton, and this helps them to squeeze through tight spots and escape potential prey.  The body of the octopus is soft, but it does have a hard beak.  The mouth of the octopus is in the center of the arms.  The octopus is considered to be highly intelligent.  To hide from predators, the octopus will leave rapidly, release ink, hide, and change their color in order to be camouflaged.  All octopuses are venomous, but the only ones that have been found to be deadly to humans are the small-ringed octopus. 

      Most octopuses do not live a very long life.  Some species will live for only about six months, but some species that are larger may survive for up to five years.  One interesting fact about the octopus is that it often dies as a result of reproduction.  The males normally die shortly after they mate, and females often die shortly after the eggs have been hatched.  Many octopuses are eaten, particularly in Japan.   Some octopuses are even eaten alive in some areas.  Some people try to keep them as pets, but often they are able to escape secure cages.

Sea Fish

      There are many fish that live in the sea, but some less known fish live in the photic zone, and they are called deep sea fish.  These fish include the lanternfish, flashlight fish, cookiecutter shark, bristlemouths, anglerfish, and viperfish. 

      Lanternfish have a thin and compressed body with silvery small scales.  Their head is rounded and their eyes are round too.  They have a jaw with multiple rows of small teeth.  The fins are small and they have one high dorsal fin.  The lanternfish may be between two centimeters to thirty centimeters in length.  The fish may be iridescent blue, silver, green, dark brown, or black.  Lanternfish highly populate the sea floor. 

Lanternfish

     Flashlight fish live in tropical water around the world.  They normally will stay in the deep water of the sea.  They are normally about 14 centimeters in length as adults, but some will grow to twice this size.  They usually feed on small crustaceans.  They have large bioluminescent organs.  They use their light to communicate and attract prey.

Flashlight Fish

      The cookiecutter shark is small, and can become about 20 inches in length.  They are long and thin, and are characterized by their cigar shape.  Their eyes are large and they have green pupils.  They have very prominent teeth on their lower jaw.  The upper jaw has small teeth.  Their fleshy lips and teeth are used to latch onto fish and twist their bodies, at which point they have grabbed a circular patch of flesh and skin from their prey.  Another interesting fact about the fish is that it will eat its own worn out teeth and then digest them.  Then it will replace the teeth with a new set.

Cookiecutter Shark

     Bristlemouth fish are found in the Atlantic Ocean, Pacific Ocean, and Indian Ocean.  They have elongated bodies that are anywhere from two centimeters to thirty centimeters in length.  Their name comes from their bristle like teeth.  The fish is normally black.

Bristlemouth Fish

     Anglerfish are bony fish and they have an interesting bony growth that comes from their head and appears as a fishing pole.  Some of these fish live on the bottom of the ocean, some live deep in the sea, and others live on the continental shelf.  The unique spin protruding from their head ends in a growth of flesh at the tip of the spine.  The spine can be wiggled by the angler fish to look like a prey animal or bait.  This is used to lure prey to come close and then the anglerfish eats them whole. 

      Viperfish are deepwater fish that have long needle-like teeth and lower jaws that are hinged.  They normally grow to 30 to 60 centimeters.  They usually stay at lower depths in the ocean.  They live in temperate or tropical waters.  The viperfish may be green, silver, or black.  It has fang-like teeth that it are able to curve behind the head.  This fish has the ability to go for an extended time with no food.  In the wild, viperfish usually can live for about 15 to 30 years. 

Sea Snakes

     Sea snakes can be venomous and have adaptations that allow them to live in marine environments for the majority of their lives.  They like to live in warm coastal waters in the oceans and you will often find them near land.  They have tails that are like paddles at the end and their compressed bodies look similar to eels.  They do not have gills and must eventually come to the surface to breathe.  Some of these snakes are the most venomous of all snakes.  Most are considered docile, but some are extremely aggressive. 

     Most adult species will grow around four to five feet, but the largest of the sea snakes may grow to about nine feet.  They have small eyes.  They have fangs that are short and eighteen small teeth behind their fangs.  The tongue of a sea snake is usually shorter than the tongue of a land snake.  The also have special nostrils that will keep the water out.  The lungs of the sea snakes are very large and often extend the length of the body of the sea snake.  Many snakes also support their respiratory system through skin that helps them respire.  Sea snakes also have posterior sublingual glands that help them to get rid of salt when their tongues move.  Sea snakes normally will eat fish and eels.  Young sea snakes are born alive in the water and will live their entire lives in the sea.  Most of these snakes are venomous.

Sharks

     Sharks have long been feared due to their predatory ways.  There are actually 440 species of sharks, and they can range from seven inches in length to 39 feet in length.  They are found in all oceans.  There are two sharks, the river shark and the bull shark, which are able to exist in freshwater or saltwater.  Sharks do not have a skeleton, and this assists them by making them very flexible but also very lightweight, which helps them to achieve fast bursts of speed.  The teeth of a shark are in the gums instead of the jaws.  The teeth are replaced during its lifetime.  There are many rows of replacement teeth that grow inside the jaw and move forward in order to replace lost teeth.  Some of these shark species can lose up to 30,000 teeth during their lifetime. 

    On average, a shark will swim at an average speed of five miles an hour, but when attacking, it can swim above twelve miles an hour.  The shortfin mako is even faster, and it can reach speeds up to thirty-one miles an hour.  There are estimates that about 100 million sharks are killed by humans every year.  Sharks are eaten in many countries.  Besides the meat, shark fins are also popular in shark fin soup.

       This website will give you additional information about all of the sea creatures mentioned on this introduction page, so please click on the links at the top to learn more.