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Beluga whale - Wikipedia. The beluga whale or white whale (Delphinapterus leucas) is an Arctic and sub- Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus. Delphinapterus. This marine mammal is commonly referred to as the beluga, melonhead, or sea canary due to its high- pitched twitter.
It is adapted to life in the Arctic, so has anatomical and physiological characteristics that differentiate it from other cetaceans. Amongst these are its all- white colour and the absence of a dorsal fin. It possesses a distinctive protuberance at the front of its head which houses an echolocation organ called the melon, which in this species is large and deformable. The beluga's body size is between that of a dolphin's and a true whale's, with males growing up to 5.
This whale has a stocky body. A large percentage of its weight is blubber, as is true of many cetaceans. Its sense of hearing is highly developed and its echolocation allows it to move about and find blowholes under sheet ice. Belugas are gregarious and form groups of up to 1.
They are slow swimmers, but can dive to 7. They are opportunistic feeders and their diets vary according to their locations and the season. The majority of belugas live in the Arctic Ocean and the seas and coasts around North America, Russia and Greenland; their worldwide population is thought to number around 1. They are migratory and the majority of groups spend the winter around the Arctic ice cap; when the sea ice melts in summer, they move to warmer river estuaries and coastal areas.
Some populations are sedentary and do not migrate over great distances during the year. The native peoples of North America and Russia have hunted belugas for many centuries.
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They were also hunted commercially during the 1. Whale hunting has been under international control since 1. Currently, only certain Inuit and Alaska Native groups are allowed to carry out subsistence hunting of belugas. Other threats include natural predators (polar bears and killer whales), contamination of rivers (as with PCBs which bioaccumulate up the food chain), and infectious diseases. From a conservation perspective, the beluga was placed on the International Union for Conservation of Nature's Red List in 2.
Of seven Canadian beluga populations, the two inhabiting eastern Hudson Bay and Ungava Bay are listed as endangered. Belugas are one of the most commonly kept cetaceans in captivity and are housed in aquariums, dolphinariums, and wildlife parks in North America, Europe, and Asia. They are popular with the public due to their colour and expression. Taxonomy. The English name comes from the Russian . A Japanese researcher says he taught a beluga to . Another example is NOC, a beluga whale that could mimic the rhythm and tone of human language. Beluga whales in the wild have been reported to imitate human voices.
The bones were discovered during construction of the first railroad between Rutland and Burlington in Vermont, when workers unearthed the bones of a mysterious animal in Charlotte. Buried nearly 1. 0 ft (3. Vermont. Experts identified the bones as those of a beluga. Because Charlotte is over 1.
Join us in March for vibrant performances, lectures, family activities, and exhibitions. 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 long and upwards of 200 tons. The diet of killer whales is often geographic or population specific: Resident killer whale populations in the eastern North Pacific mainly feed on. PHYSICAL CHARACTERISTICS (Estes 1991) (Eltringham 1999) (Kingdon 1979, 1997) (Nowak 1991) Height: Common Hippo 150-165 cm (4.9-5.4 ft) Pygmy Hippo about half.
Vermont. The remains were found to be preserved in the sediments of the Champlain Sea, an extension of the Atlantic Ocean within the continent resulting from the rise in sea level at the end of the ice ages some 1. The sudden tapering to the base of its neck gives it the appearance of shoulders, unique among cetaceans. The tailfin grows and becomes increasingly and ornately curved as the animal ages.
The flippers are broad and short. The layers can be readily identified as one layer consists of opaque dense material and the other is transparent and less dense. It is therefore possible to estimate the age of the individual by extrapolating the number of layers identified and the estimated frequency with which the deposits are laid down. The study therefore estimated belugas can live for 7. It acts as insulation in waters with temperatures between 0 and 1. They then start to progressively lose their pigmentation until they attain their distinctive white colouration, at the age of seven years in females and 9 in males. When they migrate to the estuaries during the summer, they rub themselves on the gravel of the riverbeds to remove the cutaneous covering.
Under normal conditions, the spiracle is closed and an animal must contract the muscular covering to open the spiracle. The tailfin has a distinctive curvature along the lower edge. The evolutionary preference for a dorsal ridge rather than a fin is believed to be an adaptation to under- ice conditions, or possibly as a way of preserving heat. It can hear sounds within the range of 1. Hz, with the greatest sensitivity between 1. Hz. In the toothed whales, the lower jawbone is broad with a cavity at its base, which projects towards the place where it joins the cranium.
A fatty deposit inside this small cavity connects to the middle ear. It is not known if these organs are functional or simply vestigial. The presence of cone cells indicates they can see colours, although this suggestion has not been confirmed. This substance forms a film that protects the cornea and the conjunctiva from pathogenic organisms. Radio tracking has even shown belugas can start out in one pod and within a few days be hundreds of miles away from that pod.
Killer whale; Transient killer whales near Unimak Island, eastern Aleutian Islands, Alaska: Size compared to an average human.
This can represent a significant proportion of the total population and is when they are most vulnerable to being hunted. It is not unusual for an aquarium handler to be drenched by one of his charges. Some researchers believe spitting originated with blowing sand away from crustaceans at the sea bottom. Belugas also show a great degree of curiosity towards humans in the wild, and frequently swim alongside boats. Individual captive animals have been recorded at depths between 4. One study found a female beluga had 1. Myoglobin concentrations are several times greater than for terrestrial mammals, which help prevent oxygen deficiency during dives.
Some animals have been observed to suck up water and then forcefully expel it to uncover their prey hidden in the silt on the seabed. Individuals then take turns feeding on the fish. In the Canadian Arctic, calves are born between March and September, while in Hudson Bay, the peak calving period is in late June, and in Cumberland Sound, most calves are born from late July to early August. Alloparenting (care by females different from the mother) has been observed in captive belugas, including spontaneous and long- term milk production. This suggests this behaviour, which is also seen in other mammals, may be present in belugas in the wild. The sound waves rebound from objects in the water and return as echoes that are heard and interpreted by the animal.
They also use this ability when moving around the thick ice sheets of the Arctic, to find areas of unfrozen water for breathing, or air pockets trapped under the frozen sheet ice. In one study, the maximum frequencies produced by an individual located in San Diego Bay, California, were between 4. Hz. The same individual produced sounds with a maximum frequency of 1. Hz on being transferred to Kaneohe Bay in Hawaii. The difference in frequencies is thought to be a response to the difference in environmental noise in the two areas. They possess a large repertoire, as they can emit up to 1. Lawrence River in the Atlantic.
Belugas sometimes follow migrating fish, leading Alaska state biologist Tom Seaton to speculate it had followed migrating salmon up the river at some point in the previous autumn. Whales in James Bay spend winter months within the basin could be a distinct group from these in Hudson Bay. These waters usually have a temperature between 8 and 1. The scientific committee of the International Whaling Commission recognizes these 2. The IUCN estimated the world beluga population in 2.
The cured skin is the only cetacean skin that is sufficiently thick to be used as leather. In 1. 86. 3, the cured skin could be used to make horse harnesses, machine belts for saw mills, and shoelaces. These manufactured items ensured the hunting of belugas continued for the rest of the 1. The unrestricted killing of belugas continued into the 1. This practice is a part of their culture, but doubts still remain whether the number of whales killed may be sustainable. The bears swipe at the belugas and drag them onto the ice to eat them.
Attacks on belugas by killer whales have been reported in the waters of Greenland, Russia, Canada, and Alaska. The groups near to or under the sea ice have a degree of protection, as the killer whale's large dorsal fin, up to 2 m in length, impedes their movement under the ice and does not allow them to get sufficiently close to the breathing holes in the ice. Chemical substances such as DDT and heavy metals such as lead, mercury and cadmium have been found in individuals of the Saint Lawrence River population.
This condition is thought to be directly related to environmental contamination, in this case by polycyclic aromatic hydrocarbons, and coincides with the high incidence of this disease in humans residing in the area. While some populations tolerate small boats, most actively try to avoid ships. Whale- watching has become a booming activity in the St. Lawrence and Churchill River areas, and acoustic contamination from this activity appears to have an effect on belugas. For example, a correlation appears to exist between the passage of belugas across the mouth of the Saguenay River, which has decreased by 6. The presence of shipping produces avoidance behaviour, causing deeper dives for feeding, the break- up of groups, and asynchrony in dives. Animals in this location have also been recorded as suffering infections caused by herpesviruses and in certain cases to be suffering from encephalitis caused by the protozoan Sarcocystis.
Loggerhead Sea Turtles, Caretta caretta ~ Marine. Bio. org. Loggerhead Sea Turtles, Caretta caretta. Description & Behavior. Loggerhead Sea Turtles : : Marine. Bio Video Library. Caretta caretta (Linnaeus, 1. This species is the largest hard- shelled turtle in the world (the leatherback sea turtle is the largest of all turtles).
Two subspecies have been recognized: Caretta caretta gigas, found in the Pacific and Indian Oceans, and C. They may differ in the number of neural bones in the carapace and marginal scutes on the surface of the carapace, but the ranges overlap and many authorities do not support the distinction (Ernst, Lovich, and Barbour, 1. Color patterns are reddish- brown with darker streaks and their front flippers possess two claws. Subadults have carapaces 4. Sea turtles live in almost every ocean of the world.
Their smooth shells and paddle- like flippers help them speed through the water as fast as 2. These long- distance travelers have been known to swim up to 4,8.
Although sea turtles cannot withdraw their heads into their shells, the adults are protected from predators by their shells, large size and thick scaly skin on their heads and necks. Sea turtles spend almost all their lives submerged but must breathe air for the oxygen needed to meet the demands of vigorous activity. With a single explosive exhalation and rapid inhalation, sea turtles can quickly replace the air in their lungs.
The lungs are adapted to permit a rapid exchange of oxygen and to prevent gasses from being trapped during deep dives. The blood of sea turtles can deliver oxygen efficiently to body tissues even at the pressures encountered during diving. During routine activity green and loggerhead sea turtles dive for about 4 to 5 minutes and surface to breathe for 1 to 3 seconds. A female loggerhead tracked at sea made up to 5. Turtles can rest or sleep underwater for several hours at a time but submergence time is much shorter while diving for food or to escape predators. Breath- holding ability is affected by activity and stress, which is why turtles drown in shrimp trawls and other fishing gear within a relatively short time. Because sea turtles are difficult to study in the open ocean, scientists are just beginning to learn about the life history of sea turtles.
Today, radio transmitters, attached to nesting turtles, help track the sea creatures on their travels and provide valuable information. World Range & Habitat. GBIF network (map below) ~. OBIS distribution map ~. Aqua. Maps. Loggerhead sea turtles are found in coastal tropical and subtropical waters often extending to temperate waters in search of food. Found in the Atlantic Ocean from Argentina to Nova Scotia.
The highest populations in North America are found on barrier islands from North Carolina to the Florida Keys. These Florida loggerheads migrate to the Bahamas in the winter. Small populations of the Atlantic loggerhead are also found on barrier islands off of the Texas coast. Primary habitat is in southeastern United States ranging southward to South America and extending eastward to Africa and the Mediterranean as well as areas of the western Pacific and Indian Oceans. Hatchling habitat is primarily in warm ocean currents among flotsam such as sargassum mats. Adult habitat includes rock outcroppings and reefs near shore as well as in brackish lagoons and the mouths of inlets.
Long migrations often occur, especially to return to nesting beaches. Feeding Behavior (Ecology)Primarily carnivorous during most of their lives. Hatchlings often eat sponges, jellyfishes, sargassum weed, small gastropods and crustaceans. Juveniles, sub- adults and adults feed upon conch, clams, horseshoe crab as well as other crustaceans. They have powerful jaws that enable them to easily crush the hard shells of their prey. During migration through the open sea, loggerheads eat jellyfishes, pteropods, floating mollusks, floating egg clusters, squids and flying fishes. Life History. Although sea turtles move swiftly in the ocean, they are slow and defenseless on land.
Male sea turtles almost never leave the water. Female sea turtles leave the ocean only to lay eggs and, for most species, nest only at night. A female may nest every two to three years. Nesting can take between one and three hours. After a female turtle drags herself up the beach, she hollows out a pit with her back legs and deposits from fifty to two hundred eggs the size of golf balls. When the last egg is laid, the turtle covers the eggs with sand, tamps down the sand with her plastron, and flings more sand about with her flippers to erase any signs of the nest. After about two months, the hatchling turtles emerge at night.
The light reflected off the water from the sky guides them to the sea. These days, car headlights, street lamps, or lights on buildings near the beach cause some hatchlings to travel in the wrong direction. Waiting herons make fast meals of other hatchlings.
Any babies still on the beach in the morning are easily picked off by predators or die in the hot sun. It is thought that when the surviving hatchlings reach maturity, they return to the beach where they hatched to lay their eggs. Loggerhead sea turtles reach sexual maturity when adults and their shells are longer than 9. In the United States, the southeastern region from North Carolina to Florida hosts the majority of the nesting. In Florida, Brevard County beaches receive the most nesting females per year than generally any other county in Florida.
Nesting also occurs in some areas of the northeastern coasts of Mexico and minor beaches in the Caribbean. In the Mediterranean nesting is reported in Greece, Turkey, Israel as well as Italy. The Indian Ocean's major nesting sites are in South Africa as well as large nesting colonies on the Arabian Peninsula on Masirah Island, Sultanate of Oman. Nesting occurs during late spring and summer. Females renest approximately every two weeks during the nesting season laying between two and fives times a season with an average clutch size of 1.
Egg diameter is from 3. Incubation period varies, but 4. Sex determination is dependent upon the incubation temperature, therefore there is an optimal incubation temperature that ranges between 2.
The male sex is determined at cooler temperatures. Nests are often lost to predators such as raccoons, dogs, ghost crabs, sea birds and ants as well as to shoreline erosion and human predation. Hatchlings are preyed upon by mammals, sea birds, crabs and carnivorous fishes. Predation continues to be high until the turtles are big enough to avoid being swallowed by large carnivorous fishes such as groupers, snappers and jacks. Sharks are a formidable predator throughout the life cycle of sea turtles, although larger turtles can often avoid a shark attack by presenting the flat side of the plastron or carapace to prevent biting. Life Span: At least 3. Population Numbers: Unknown.
Conservation Status & Comments. Current IUCN Conservation Status of Loggerhead Sea Turtles ESA- listed species.
UNEP World Conservation Monitoring Centre: Loggerhead Sea Turtles Check the Seafood Watch List for this species. WARNING: Eating sea turtles and their eggs, anywhere, can cause severe illness and even death, especially to children. The flesh has been found to contain chelonitoxin which may cause a number of symptoms including nausea, vomiting, diarrhea, burning sensation of lips, tongue and mouth, chest tightness, difficulty swallowing, hypersalivation, skin rash, coma and death.
See the following for more information: Chelonitoxism: new case reports in French Polynesia and review of the literature. Turtle meat kills six in Micronesia. Listed as . Most loggerhead deaths occur due to drowning in shrimp nets, as well as due to longline fishing practices. Other reasons for being federally listed are due to predation of eggs in countries who utilize them as a primary means for food as well as sell them on the black market. Loggerheads are a big part of the diet of some rural communities, such as in the Antillean and Caribbean areas.
Much money is paid for their meat and eggs, which are used to make turtle burgers and turtle soup and the eggs are even used to make cakes. In Cuba, the eggs are dried in the oviduct and sold like sausage.
The turtles also provide oxidizing oil, which acts like varnish. In Honduras, boat paddles are made out of their shells. Loggerhead sea turtles, Caretta caretta, are now listed as Endangered (EN A1abd) on the IUCN Red List of Threatened Species due to.
FAO Fisheries Synopsis No 1. Volume 1. 1Loggerhead Sea Turtles - Office of Protected Resources - NOAA Fisheries. Euro. Turtle - a website for marine turtle education. U. S. Fish & Wildlife Service Endangered Species.
Dodd Jr., Kenneth C. Synopsis of the Biological Data on the Loggerhead Sea Turtle Caretta caretta (Linnaeus 1. Biological Report 8. May 1. 98. 8, (FAO Synopsis NMFS- 1. Fish and Wildlife Services, U. S. Department of the Interior, 1. Seaturtle. org. The State of the World's Sea Turtles (SWo.
T)Ernst, C., J. Turtles of the United States and Canada. Washington, District of Columbia, USA: Smithsonian Institution Press. IUCN/SSC Marine Turtle Specialist Group 1.
IUCN Red List of Threatened Species. Downloaded on 2. 3 December 2. Research. Caretta caretta ยป.
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