Hagfish

Hagfish have no true fins and have six or eight barbels around the mouth and a single nostril.

Hagfish are marine craniates of the class Agnatha or Myxini, moreover reputed to be Hyperotreti. Some specialists respect Myxini as not having a place with the subphylum Vertebrata. That is, they are the just living beasts that have a skull but not a vertebral section.

Leafy Seadragon

The Leafy Seadragon uses the fins along the side of its head to allow it to steer and turn. However, its outer skin is fairly rigid, limiting mobility.

Much like the seahorse, the Leafy Seadragon's name is derived from its resemblance to another creature (in this case, the mythical dragon). While not large, they are slightly larger than most seahorses, growing to about 20–24 cm (8–10 in). They feed on plankton and small crustaceans.

Hermit Crabs

Instead of growing a natural shell of its own, the recluse crab makes utilize of a used shell for protection.  It often shares this “home” with other animals such as sea anemones, barnacles, and worms.

Hermit crabs are scavengers on the seashore and seabed. They contrast from the true crabs on account of they make a point not to have a fifth pair of walking legs. Their fourth pair of legs is very small and can be seen only when the animal is removed from its snail shell home. This pair of legs grips the inside of the shell and holds the animal in place.

Starfish

With their perfectly shaped and attractively colored bodies, starfish are reminders of happy seaside vacations.

Starfish are the most generally viewed parts of the echinoderms; the spiny-skinned animals. All echinoderms have five-sided bodies, and this shape can be seen in many starfish. When grown-up, the body of a typical starfish is drawn out in five rays, or arms, radiating from a central point.

Squid

With their torpedo-shaped bodies, powerful suckers, and acute senses, as well as their fitness to move or cover themselves with stupendous quickness, squid are among the most sophisticated of all ocean hunters.

Squid belong to the group of mollusks known as cephalopods, which also includes octopuses and cuttlefish. The word “cephalopod” means “head-foot.” In cephalopods, the muscular foot seen in most other mollusks has been modified into powerful, suckered tentacles that are attached to the front of the head.

Sponges

Extremely ancient animals, sponges have displayed following Precambrian times, 540 million years ago, and have changed little since that time. The familiar bathroom sponge is made from a sponge skeleton.

Sponges exist principally connected to the seabed. They are upheld by a skeleton lying among the external and inward layer of units of the form. The skeleton is made of calcium carbonate, spongin (a protein) or glasslike silica, depending to the type of sponge. The large number of hard skeletal parts in sponge bodies means there are many fossils to explore.

Sea Anemones

Sea anemones may look delicate and flowerlike, yet these simple animals are dangerous predators lying in wait for any small prey that may blunder into their outstretched tentacles.

Sea anemones were prominent with right on time naturalists who found them effortless to keep in their marine aquariums. Worldwide, there are a considerable number of grandly shaded and designed species. Sea anemones are closely related to corals. The sea anemone’s saclike body is a hollow column with the mouth at the top. It is surrounded by one or more rings of tentacles.

Octopuses

Octopuses are the most remarkably propelled of every last trace of the mollusks. Most octopuses live on the sea floor where they hunt live prey, but some kinds are specialized swimmers found in the deep sea.

Octopuses are relatives of squids, and have much in common with them. Both exist just in the ocean, both have soft figures, both have suckered tentacles for handling prey, and both have a horny snout to slash up sustenance. Octopus eyes are similar in design to our own. Octopuses also have big brains. In fact, they are probably the most intelligent invertebrates. In captivity they quickly learn new tricks, such as unscrewing the lid of a jar to get at food inside. They are not sociable animals, though—most prefer to live on their own.

Oysters

Individuals have gathered palatable oysters for thousands of years. Pearl oysters, processing valuable pearls, have a place with a divided clan that is just indirectly identified with them.

Edible, or true, oysters are bivalves (two-shelled mollusks related to clams and mussels). Like other bivalves they have no head or brain, and live quiet lives on the sea floor. They food by drawing momentums of ocean water into their forms, from which they sift out little nourishment particles.

Sea Slugs

A significant number of sluglike mollusks exist in the universe's seas. They are relatives of the slugs that live on terrain, but unlike them, these marine animals frequently go in brilliant colors and bizarre shapes.

The most drastically significant amass of sea slugs are the nudibranchs. “Nudibranch” denotes “naked gills,” on account of the gills develop as fluffy tufts on the back, not stowed away from view as in different mollusks. Nudibranchs exist essentially on the ocean bottom, slithering in on their bulky foot.

Mantis Shrimp

These vivid scavangers are furious pursuers. Their front appendages pack a punch robust enough to break the glass of an aquarium. It is not shocking that this capacity is additionally utilized to catch prey.

Mantis shrimp are distant relatives of true shrimp, crabs, and lobsters. Their most famous feature is their second pair of limbs, which are enlarged into deadly attacking weapons. They can shoot out a sharp, jagged blade with a fistlike club,with lightning speed to attack prey. Different species can be classed as “smashers” or “spearers,” depending on which part of their weapon is best developed.

Conger Eels

These large, predatory eels can often be caught near the coast by anglers, because they often lurk around jetties. Conger eels are also frequently found by divers exploring wrecks.

Conger eels are shy fish, preferring to stay out of sight and retreating into their hiding places if they feel threatened. In shallow waters they are usually nocturnal. They emerge under cover of darkness and often swim out across sandy areas in search of prey, which they grab with their powerful

Sea Lilies

The sea lilies and their relatives the feather stars are echinoderms (spiny-skinned animals) that have survived for 500 million years with hardly any changes. They give us a glimpse of what life was like in the ancient Cambrian seas.

Sea lilies and feather stars belong to the same family of spiny-skinned animals as starfish, sea urchins, and sea cucumbers. The body of an adult sea lily is attached to the deep ocean floor by a stalk. Feather stars usually live in shallower water. They are only attached to the ocean floor when they are growing; when they become

Krill

Looking a lot like shrimp, these tiny crustaceans are found in enormous numbers in the world’s oceans, where they are one of the main food sources for many other marine creatures.

Krill are tiny crustaceans (animals belonging to the group that includes shrimp and crabs). Krill are found worldwide as part of the plankton, often near the surface and especially in the polar seas.They are very abundant in the Southern Ocean around Antarctica, frequently occurring in huge numbers. Krill feed on minute floating plants called phytoplankton. In turn, krill are preyed on by whales which sieve the surface waters swallowing tens of thousands of them in one gulp—up to 4 tons in one day’s feeding! Different whale species are adapted to take krill of different sizes. 

Nautiluses

Nautiluses are relatives of squids and octopuses that are found in warm waters. Unlike them, but like other mollusks such as snails, nautiluses grow a protective shell on the outside of their bodies.

Present-day nautiluses live in waters between 250 and 1,000 feet deep, and swim mainly near the sea bottom. Nautiluses are nocturnal, retreating to deeper water during the day, presumably to avoid predators. The beautiful coiled shell of a nautilus is divided internally into separate airtight compartments. Most are empty, and the animal’s body occupies only the biggest and most recently formed compartment. The empty chambers, mainly filled with air at low pressure, make the nautilus lighter in the water. The animal is not light enough to float, however, and squirts water from

Barnacles

Choosing the right place to settle is a major step for young barnacles, as they must choose a favorable spot where they can safely grow. If they make the wrong choice they will suffer, as they cannot move again.

Barnacles are marine animals, commonly found on rocks, driftwood, shells of turtles, whales, and among corals. The acorn barnacles are usually found on the middle part of the seashore. Here, they are regularly covered and uncovered by the tides which bring them food and oxygen. They have small volcanoshaped shells made of four to six plates cemented directly on the rocks. At the top is an opening guarded by more shell plates.These can be opened, and then closed tightly to keep water inside when the tide goes

Seahorses

With their upright posture, horselike head, curious swimming action, and their habit of hanging onto seaweeds with their tail, seahorses do not really look like fish at all.

Despite their strange appearance, seahorses are true fish.They are placed in a family that boasts several other “unfishlike” members. These include the seadragons and pipehorses, as well as the pipefish. Some of these species look like bunches of drifting seaweed and others look like thin tubes.

Unfishlike Features

A seahorse swims with its body held vertically in the water, instead of horizontally as in other fish. Therefore its head is positioned at right angles to the rest of the body so that the seahorse can see and feed properly. The seahorse’s tail is also unusual. It does not have a fin. Instead,

Lancelets

Although they resemble eel-like fish, the humble lancelets are in fact a primitive group that are part way between those animals that do not have a backbone (invertebrates) and those that do (vertebrates).

Lancelets are small marine animals that spend much time burrowing in the seabed, although they can swim.Their narrow, fishlike body is pointed at both ends. They have a narrow dorsal (back) fin and a small, rounded tail fin.The head of a lancelet is small and has no eyes. There is a well-developed nerve cord that connects with a simple brain. The brain is not enclosed in a braincase.The mouth has no jaws or teeth, and

Sea Cucumbers

Sea cucumbers are sluggish, often brightly colored creatures with cylindrical or sausageshaped bodies. Yet, despite their unusual looks, they have many remarkable qualities.

Sea cucumbers belong to the large group of animals known as echinoderms (spiny-skinned animals) that includes the starfish and the sea urchins. Sea cucumbers are closely related to sea urchins. The sea urchins have a rigid outer skin, called a test, but the outer skin of sea cucumbers is not rigid. Instead, it is made up of chalky plates loosely set in a flexible body wall. The body wall has muscles that allow it to change shape. Three rows of tube feet run along the underside of the body and two run along the top. Tube feet are

Sea Urchins

These prickly animals have highly developed, moveable spines used for defense as well as for moving around. Sea urchins have colonized most types of seabed from rocky shores to deep-sea bottoms.

Sea urchins are echinoderms (spiny-skinned animals). They are related to the starfish, sea lilies, and sea cucumbers. They come in two basic body shapes. Round ones are called regular echinoids. Oval or heart-shaped ones are called irregular echinoids. All urchins have a chalky body called a test, which is covered in spines of varying lengths.