Blue Whales

Blue whales are the largest animals ever known to have lived on Earth. These magnificent marine mammals rule the oceans at up to 100 feet (30 meters) long and upwards of 200 tons (181 metric tons). Their tongues alone can weigh as much as an elephant. Their hearts, as much as an automobile. Blue whales reach these mind-boggling dimensions on a diet composed nearly exclusively of tiny shrimplike animals called krill. During certain times of the year, a single adult blue whale consumes about 4 tons (3.6 metric tons) of krill a day. Blue whales are baleen whales, which means they have fringed plates of fingernail-like material, called baleen, attached to their upper jaws. The giant animals feed by first gulping an enormous mouthful of water, expanding the pleated skin on their throat and belly to take it in. Then the whale's massive tongue forces the water out through the thin, overlapping baleen plates. Thousands of krill are left behind—and then swallowed. Blue whales look true blue underwater, but on the surface their coloring is more a mottled blue-gray. Their underbellies take on a yellowish hue from the millions of microorganisms that take up residence in their skin. The blue whale has a broad, flat head and a long, tapered body that ends in wide, triangular flukes. Blue whales live in all the world's oceans, occasionally swimming in small groups but usually alone or in pairs. They often spend summers feeding in polar waters and undertake lengthy migrations towards the Equator as winter arrives. These graceful swimmers cruise the ocean at more than five miles an hour (eight kilometers an hour), but accelerate to more than 20 miles an hour (32 kilometers an hour) when they are agitated. Blue whales are among the loudest animals on the planet. They emit a series of pulses, groans, and moans, and it’s thought that, in good conditions, blue whales can hear each other up to 1,000 miles (1,600 kilometers) away. Scientists think they use these vocalizations not only to communicate, but, along with their excellent hearing, to sonar-navigate the lightless ocean depths. Blue whale calves enter the world already ranking among the planet's largest creatures. After about a year inside its mother's womb, a baby blue whale emerges weighing up to 3 tons (2.7 metric tons) and stretching to 25 feet (8 meters). It gorges on nothing but mother's milk and gains about 200 pounds (91 kilograms) every day for its first year. Blue whales are among Earth's longest-lived animals. Scientists have discovered that by counting the layers of a deceased whale's waxlike earplugs, they can get a close estimate of the animal's age. The oldest blue whale found using this method was determined to be around 110 years old. Average lifespan is estimated at around 80 to 90 years.Between 10,000 and 25,000 blue whales are believed to still swim the world's oceans. Aggressive hunting in the 1900s by whalers seeking whale oil drove them to the brink of extinction. Between 1900 and the mid-1960s, some 360,000 blue whales were slaughtered. They finally came under protection with the 1966 International Whaling Commission, but they've managed only a minor recovery since then. Blue whales have few predators but are known to fall victim to attacks by sharks and killer whales, and many are injured or die each year from impacts with large ships. Blue whales are currently classified as endangered on the World Conservation Union (IUCN) Red List.
Credits go to: National Geographic

Jellyfish

The jellyfish body lacks any skeletal structure and comprises of a gelatinous substance, which is 95% water. Thus, their bodies are soft and can get damaged easily. Only 5% of the jellyfish body is solid matter. Aquatic surroundings are vital for jellyfish as they need water to support their bodies. Lack of water in their surroundings causes them to collapse and die. Jellyfish exhibit a perfectly symmetrical body, wherein the body parts radiate from the central axis. This perfect symmetry not only enables the jellyfish to detect food from all sides, but also helps it to respond to danger from every direction. One of the interesting jellyfish facts is that they have no blood, brain and nervous system. They possess a neural net and eye spots which are capable of sensing light from dark. Chemosensory pits help them identify food and prey. Jellyfish have tentacles featuring a number of capsule-like apparatus filled with toxins. These toxins cause paralysis when the tentacles come in contact with something. These tentacles are used to catch prey as well as defend against predators. Jellyfish are carnivorous and feed on crustaceans, zooplankton, tiny fish and larvae. They trap different marine organisms with their tentacles while floating in water. The nasty sting from the tentacles renders the prey paralyzed or dead. Jellyfish is eaten by scores of people across the globe. However, the initial reaction to the thought of consuming jellyfish is that of dread and revulsion. People often loathe the thought of eating something bland, rubbery and wet. People who have acquired a taste for jellyfish find it less difficult to eat them. Jellyfish has no flavor of its own; cooked jellyfish takes on the flavor of the soy sauce or vinegar. When added to salads, the jellyfish takes on the flavor of the other salad ingredients. The cannonball jellyfish or the Stomolophus meleagris are larger and have more rigid bodies, and are therefore the most popular ones used in dishes. Their nutritional content makes them a healthy snack. One of the comforting jellyfish facts is that the jellyfish available in the market for consumption are venom-free. To neutralize the venom in the tentacles, the jellyfish are processed in salt and alum. Such processing is necessary to prevent the jellyfish from rotting. Thus, people need not fear the venomous stings. Jellyfish population has increased drastically and is causing scores of problems to human beings living on the coastal front. The number of people stung by jellyfish has risen dramatically. Most jellyfish do not cause any substantial harm. However, some can spearhead extreme reactions, resulting in even death. Jellyfish also cause a lot of nuisance to ships and carriers in the ocean. Jellyfish generally live and move in large swarms (billions!), and are often observed to hamper the movements of vessels in the ocean. The water inlets of the vessels get clogged up, and have to be cleared of masses of dead jellyfish on a regular basis for the vessels' efficient operation.
Credits go to: Buzzle.com

Sea Lions

The Steller sea lion is the largest member of the Otariidae (eared seal) family. Steller's sea lions inhabit the cooler waters of the North Pacific. They are divided into two stocks - the western population (Gulf of Alaska, Bering Sea, Russia and Japan), and the eastern population (California, British Columbia and south east Alaska). This species gets its name from a German naturalist named George Wilhelm Steller who was the first to study the animal in 1742. Steller's sea lions are suffering massive, inexplicable population losses and are listed as endangered.
Steller’s sea lions are marine mammals and members of the suborder Pinnipedia (which in Latin means “fin-footed”). Male Steller’s sea lions average 907 kg (2,000 lbs) in weight and 3 m (10 ft) in length; females average 272 kg (600 lbs) and 2.1 m (7 ft) in length. When dry, Steller’s have very thick, yellowish-brown fur but appear darker when wet. Mature males develop a heavy muscular neck with a mane of long, coarse hair. Steller sea lion pups are black in color and weigh from 18 – 22 kg (40 - 48.5 lbs) and are about 1 m (3.3 ft) in length. Pups are dark brown to black until 4 to 6 months old when they molt to a lighter brown. By the end of their second year, pups have taken on the same pelage color as adults. Bulls become mature between 3 and 8 years of age, but typically are not massive enough to hold territory successfully until 9 or 10 years old. Females reproduce for the first time at 4 to 6 years of age, bearing at most a single pup each year. Eared seals are able to control their hind flippers independently, allowing them to be particularly agile on land and, unlike the true seals, they swim using their foreflippers .
Steller sea lions are opportunistic predators, feeding primarily of a wide variety of fishes and cephalopods. Prey varies geographically and seasonally, however, it is known that they feed near the shore on squid, octopus and fish, such as herring, mackerel and salmon. Steller sea lions have been known to prey on harbour seal, fur seal, ringed seal, and possibly sea otter pups, but this would represent only a supplemental component to the diet.In spring, Steller’s gather at breeding areas called “rookeries”. Males arrive in May, staking out territories before the females come ashore. When the females arrive, they are herded into a bull’s territory to form a “harem” – a loosely connected group of 15 or more females. Soon after they arrive, females give birth to a pup conceived the previous year. The pups remain with their mother for about one year but often gather in groups with the other pups to play and engage in mock battles. When pups are a year old, they are called “yearlings.” Mating occurs during June and July shortly after pups are born (insuring next year’s pups). Gestation lasts 10 –11 months. In August, the males leave the rookeries, followed in a few months by the females. Most males remain in northern waters all year. Females and pups, however, migrate as far south as Baja California, and Mexico. Young male Steller’s sea lions do not return to the rookeries until they are 2 or years old. Known as “bachelors”, they remain isolated until they are large enough to compete with mature adult males for a territory.
Males are polygamous and territorial on land. They defend the boundaries of their territories with ritual threat displays to other males.
Credits go to: Whale-Images

The Manatee

West Indian manatees are large, gray aquatic mammals with bodies that taper to a flat, paddle-shaped tail. They have two forelimbs, called flippers, with three to four nails on each flipper. Their head and face are wrinkled with whiskers on the snout. The manatee's closest relatives are the elephant and the hyrax (a small, gopher-sized mammal). Manatees are believed to have evolved from a wading, plant-eating animal. The West Indian manatee is related to the West African manatee, the Amazonian manatee, the dugong, and Steller's sea cow, which was hunted to extinction in 1768. The average adult manatee is about 10 feet long and weighs between 800 and 1,200 pounds. Manatees can be found in shallow, slow-moving rivers, estuaries, saltwater bays, canals, and coastal areas — particularly where seagrass beds or freshwater vegetation flourish. Manatees are a migratory species. Within the United States, they are concentrated in Florida in the winter. In summer months, they can be found as far west as Texas and as far north as Massachusetts, but summer sightings in Alabama, Georgia and South Carolina are more common. West Indian manatees can also be found in the coastal and inland waterways of Central America and along the northern coast of South America, although distribution in these areas may be discontinuous.Manatees are gentle and slow-moving animals. Most of their time is spent eating, resting, and traveling. Manatees are completely herbivorous. They eat a large variety of submerged, emergent, and floating plants and can consume 10-15% of their body weight in vegetation daily. Because they are mammals, they must surface to breathe air. They may rest submerged at the bottom or just below the surface of the water, coming up to breathe on an average of every three to five minutes. When manatees are using a great deal of energy, they may surface to breathe as often as every 30 seconds. When resting, manatees have been known to stay submerged for up to 20 minutes. Manatees can swim up to 20 miles per hour in short bursts, but they usually only swim about three to five miles per hour.West Indian manatees have no natural enemies, and it is believed they can live 60 years or more. As with all wild animal populations, a certain percentage of manatee mortality is attributed to natural causes of death such as cold stress, gastrointestinal disease, pneumonia, and other diseases. A high number of additional fatalities are from human-related causes. Most human-related manatee fatalities occur from collisions with watercraft. Other causes of human-related manatee mortality include being crushed and/or drowned in canal locks and flood control structures; ingestion of fish hooks, litter, and monofilament line; and entanglement in crab trap lines. Ultimately, loss of habitat is the most serious threat facing the approximately 3,800 manatees in the United States today. The reproductive rate for manatees is low. Some female manatees do not sexually mature until they are five years of age, and males mature at approximately seven years of age. It is believed that one calf is born every two to five years, and twins are rare. The gestation period is about a year. Mothers nurse their young for one to two years, during which time a calf remains dependent on its mother. Credits go to: Save the Manatee Club

Swordfish

Swordfish (Xiphias gladius) are large, highly migratory, predatory fish characterized by a long, flat bill in contrast to the smooth, round bill of the marlins. Swordfish are elongate, round-bodied, and lack teeth and scales as adults. They reach a maximum size of 14 ft (4.3 m) and 1,190 lb (540 kg). The International Game Fish Association's all-tackle angling record is a 1,182 lb (536 kg) fish taken off Chile in 1953. They are the sole member of their family Xiphiidae. The swordfish is known as The Gladiator (gladius) because of the sharp, sword-like bill it wields as a weapon – to spear prey as well as for protection from its few natural predators. The mako shark is one of the rare sea creatures big enough and fast enough to chase down and kill an adult swordfish. Swordfish are distributed throughout the world's marine ecosystem, in tropical, subtropical and temperate waters, between approximately 45° north and 45° south[1]. They tend to concentrate where major ocean currents meet, and along temperature fronts. They inhabit the mixed surface waters where temperatures are greater than 15 °C but also can move and hunt in water as cool as 5 °C for short periods aided by specially adapted heat exchange organs which are able to increase the temperature of their brain and eyes by 10-15 °C. Areas of greater apparent abundance occur north of Hawaii along the North Pacific transition zone, along the west coasts of the U.S. and Mexico and in the western Pacific, east of Japan. Migration patterns have not been described although tag release and recapture data indicate an eastward movement from the central Pacific, north of Hawaii, toward the U.S. West Coast. Acoustic tracking indicates some diel movement from deeper depths during the daytime and moving into the mixed surface water at night. At times they appear to follow the deep scattering layer, and small prey, as they undertake these vertical movements.
Credits go to: Swordfishing Central

Manta Rays

Data from 2001/2002 suggests a local population of about 177,220 in the Gulf of California. Populations around Hawaii appear to be stable. Most other populations worldwide are declining.The manta ray is the largest of the rays, with distinctive 'wings' or pectoral fins measuring over 25 feet in width, and unique 'horns' or cephalic fins on either side of their head. Manta rays have black, dark brown or blue backs and a white underside. This species is found in temperate and tropical waters around coral reefs, continents, seamounts and islands.Manta rays are largely plankton-feeding, but also feed on fish larvae and small organisms. Manta rays have reduced, nonfunctional teeth, which do not enable them to consume larger species.These creatures use their 'horns' to direct plankton and water into their mouth. Manta rays are known to migrate all over the world in search of upwelling, plankton-rich waters. During times of mating, mantas gather in large numbers and females are courted by several males. When courtship is successful, reproduction occurs belly-to-belly. Mantas reproduce via aplacental viviparity, meaning they hatch from eggs, but the eggs hatch and the babies develop inside the mother where there is no placenta for nourishment.Gestation is around a few months and 1-2 manta "pups" are born rolled up. Baby mantas become active as soon as they 'unroll'. To breathe, manta rays have five pairs of gills on their underside.
Unlike other rays, mantas lack a spine on the tail and their only defenses are their size and 'wings'. They are not threats unless attacked or threatened. The Hawaiian Islands and Island of Yap populations have a closed population structure, meaning they rarely venture from their coastal waters or migrate away from the island groups.
Manta rays are known to live in over 20 years. Credits go to: Greenpeace

Clown Fish

Clownfish can grow to be from 2 to 5 inches long. The males tend to be significantly smaller than the females. However, there are various types of clownfish that range in colours from blue to yellow.Clownfish live in a "symbiotic" relationship with certain anemones. This means they benefit from living with the sea anemone, and the sea anemone benefits from the presence of the clownfish. They are the only fish that are able to live in sea anemones and not get stung by their tentacles. Clownfish are very active fish and are extremely aggressive. Because they are quite active, the clownfish are thought to be "clowning around". They defend their territory and the sea anemone that they live in. Clownfish eat the leftovers from fish on the anemone and algae. The leftovers include copepods, isopods and zooplankton. Clownfish have a few ocean predators, but their greatest threat is humans. People who catch clownfish and keep them as pets in aquariums are making a mistake. There are only ten out of more than one thousand types of anemone that are able to host these fish. Many people put the fish in a tank with the wrong anemone. In captivity, the clownfish can live from 3 to 5 years. In the wild, they live 6 to 10 years. Credits go to: Clownfish Biology

The Great White Shark

Great Whites are the largest predatory fish on the earth. They grow to an average of 15 ft in lenth, but sharks over 20 ft and weighing around 5,000 lbs have been recorded. They have gray upper bodies which blend into the sea floor, but they get their name from their white stomaches. They are stream-lined, torpedo-shaped swimmers with powerful tails that can propel them through the water at up to 15 mph. They can leave the water completely, breaching like whales when attacking prey from underneath. Highly adapted predators, their mouths have 300 serrated, triangular teeth arranged in several rows, and they have a sharp sense of smell to detect prey. They even have organs that can sense the tiny electromagnetic fields generated by animals. Their main prey list includes sea lions, seals, small-toothed whales, and even sea turtles, and carrion. Found in cool, coastal waters throughout the world, there's no reliable data on the Great White's population. However, we know that their numbers are decreasing, due to over-fishing and accidental catching in nets, so they are listed as endangered species.

Credits go to: National Geographic

Sea Sponges

Although they may look plant-like, sea sponges are the simplest of multi-cellular animals. A sea sponge is a bottom-dwelling creature, which attaches itself to something solid in a place where itcan, hopefully, recieve enough food to grow. The scientific term for sea sponges is Porifera, which literally means "pore-bearing". A sea sponge is covered with tiny pores, called ostia, which lead internally to a system of canals and eventually out of one or more larger holes, called oscula. Within the canals of the sea sponge, chambers are lined with specialized cells called choanocytes, or collar cells. The collar cells have a sticky, funnel-shaped collar and a hair-like whip, called a flagellum. The collar cells have to purposes. They beat their flagella back and forth to push water through the sponge. The water brings nutrients, oxygen, and the collars pick up tiny bits of food in the water. Another type of cell, named an amebocyte, carries food throughout the sea sponge. Sponges are filter eaters and they can eat small particles of bacteria, or very large particles. The sea sponge is made of tiny needle-like splinters called spicules, a mesh of spongin. Many sea sponges can only be seen through microscopic examination, which makes taking photographs of them very difficult. Credits go to: Google