Dolphins

The Dolphin VS. The Human By. Aurora Simms & Chase Ridgway

__What Is the Digestive System?__ Every morsel of food we eat has to be broken down into nutrients that can be absorbed by the body, which is why it takes hours to fully digest food. In humans, protein must be broken down into amino acids, starches into simple sugars, and fats into fatty acids and glycerol. The water in our food and drink is also absorbed into the bloodstream to provide the body with the fluid it needs.The digestive system is made up of the alimentary canal and the other abdominal organs that play a part in digestion, such as the liver and pancreas. The alimentary canal (also called the digestive tract) is the long tube of organs including the esophagus, the stomach, and the intestines that runs from the mouth to the anus. An adult's digestive tract is about 30 feet long.

__What is the Excretory System?__ The excretory system is a passive biological system that removes excess, unnecessary materials from an organism so as to help maintain homeostasis within the organism and prevent damage to the body. It is responsible for the elimination of the waste products of metabolism as well as other liquid and gaseous wastes, as urine and as a component of sweat and exhalation. As most healthy functioning organs produce metabolic and other wastes, the entire organism depends on the function of the system; however, only the organs specifically for the excretion process are considered a part of the excretory system. The primary function of the excretory system is to get rid of wastes, eliminates useless by-products excreted from cells,eradicates harmful chemical build-ups and maintains a steady, balanced chemical concentration

__What is the Respiratory System?__ The respiratory system brings air into the body and removes carbon dioxide. It includes the nose, trachea, and lungs. When you breathe in, air enters your nose or mouth and goes down a long tube called the trachea. The trachea branches into two bronchial tubes, or primary bronchi, which go to the lungs. The primary bronchi branch off into even smaller bronchial tubes, or bronchioles. The bronchioles end in the alveoli, or air sacs. Oxygen follows this path and passes through the walls of the air sacs and blood vessels and enters the blood stream. At the same time, carbon dioxide passes into the lungs and is exhaled.

__What is the Circulatory System? __ The Circulatory system is made up of the vessels and the muscles that help control the flow of the blood around the body. This process is known as circulation. As the blood begins to circulate it leaves the heart from the left ventricles and goes into the aorta.The circulatory system is responsible for transporting materials throughout the entire body. It transports nutrients, water, and oxygen to your billions of body cells and carries away wastes such as carbon dioxide that body cells produce. It is an amazing highway that travels through your entire body connecting all your body cells.

__What is the Nervous System? __ The nervous system is the control system and the network of communication for the body. The nervous system is made up of nerves, the spinal cord and the brain. The nerves control everything we do; they carry messages that tell us to move, to breathe, to feel and to think. Nerves run to the muscles, organs, heart, lungs, blood vessels, brain--even to our teeth and skin. There are two sets of nerves: the central nervous system and the peripheral (outside) nervous system.

__What is the Locomotion (Muscular and Skeletal System)? __ Your Skeletal system is all of the bones in the body and the tissues such as tendons, ligaments and cartilage that connect them.The main job of the skeleton is to provide support for our body. Without your skeleton your body would collapse into a heap. Your skeleton is strong but light. Without bones you'd be just a puddle of skin and guts on the floor. The muscular system makes up nearly half the weight of the human body, this is why when we train we sometimes put on weight instead of losing it. We put on muscle weight. The muscles provide the forces that enable the body to move. Muscles stretch across joints to link one bone with another and work in groups to respond to nerve impulses.

__The Human: __ The human body contains the digestive system,the excretory system, the respiratory system, the circulatory system, the nervous system and the locomotion (skeletal and muscular system).

**Digestive System-** The digestive system helps us to digest the food that we eat. It is our source of life and without it we will die. The food is digested or broken down and gives nutrients to the body.The mouth chews up the food and makes it easier to digest. Our salivary glands which are located under the tongue and near the lower jaw, begin producing saliva. This flow of saliva is set in motion by a brain reflex that's triggered when we sense food or even think about eating. In response to this sensory stimulation, the brain sends impulses through the nerves that control the salivary glands, telling them to prepare for a meal. As the teeth tear and chop the food, saliva moistens it for easy swallowing.From the throat, food travels down a muscular tube in the chest called the esophagus. Waves of muscle contractions called peristalsis force food down through the esophagus to the stomach.The stomach's main function is digestion. It does this by storing the food we eat,and breaking down the food into a liquidity mixture called chyme.mixing enzymes which is are chemicals that break down food.The small intestines are responsible for absorbing most of the nutrients found within your food. By the time ingested food reaches the small intestine, it has been mechanically broken down into a liquid.The liver serves to store glycogen, vitamin A, vitamin D, vitamin B12, iron, and copper. It also breaks down toxic substances, turning them into proteins that can be excreted safely, and produces bile, a substance that facilitates digestion of lipids (fats) in the intestine.The gallbladder main job is to store bile and concentrate. The pancreas produces enzymes that help with the digestive process.The purpose of the large intestine is to absorb water from the undigested food back into the blood. **LINK** :[| http://www.sciencebob.com/research/digestion.php]

**Excretory System-** The excretory system includes the kidneys (nephrons) ureters, urinary bladder, and the urethra. The kidneys main function is a homeostatic regular. Your body has equilibrium levels for salt content, water content, core temperature, blood pressure and blood volume. The kidney are a pair of organs that help to maintain proper water and electroyte balance, reggulate acid base concentration, and filter the blood of metabolic wastes,which are then excreted as urine. The urinary bladder stores and releases urine. The bladder also expels urine into the uretha by a process called micturition also known as urination. Micturition involves the action of both voluntary and involuntary muscles. The urethra is the passage way through which urine is discareged from the body. There are two ureters, are leading from each kidney to the urinary bladder. Each of these transport urinne from the renal pelvis of the kidney to which is attached, to the bladder. [] 

Respiratory System- The respiratory system includes the nose (nasal cavity), the pharynx, the larynx, the trachea, the bronchi, the alveoli, respiration and the diaphragm. Three main functions of the respiratory system includes it transport air into the lungs, it facilitates the diffusion of oxygen into the blood stream and it helps remove carbon dioxide.The nose well nasal cavity cleans, moisturizes, and warms the air that enters.The pharynx is also known as the throat it is part of the respiratory tract because it allows air to flow in and out of your lungs. The larynx is known as the voice box as it is where sound is generated. It also helps protect the trachea by producing a strong cough reflex if any solid objects pass the epiglottis. The Trachea is sometimes called the windpipe. The trachea filters the air we breathe and branches into the bronchi. The bronchi are two air tubes that branch off of the trachea and carry air directly into the lungs. The alveoli is an individual hollow cavities contained within alveolar sacs (or ducts). Alveoli have very thin walls which permit the exchange of gases oxygen and carbon dioxide. They are surrounded by a network of capillaries, into which the inspired gases pass. There are approximately three million alveoli within an average adult lung.The diaphragm is a broad band of muscle which sits underneath the lungs, attaching to the lower ribs, sternum and lumbar spine and forming the base of the thoracic cavity. [] []

Circulatory System- The circulatory system has four heart chamber two atria and two ventricles,it includes the heartbeat, blood vessels (arteries, capillaries, vein), and the blood (plasma,hemoglobin,platelets). The heart has four chamber chambers two atria and two ventricles. Veins carry blood from the body, except for the lungs. Arteries carry blood away from the heart. The coronary arteries supply the heart with blood. The heart beats begins when the heart muscles relax and the blood flows into the atria. The atria then contracts and the valves open to allow blood into the ventricles. The valves closes to stop blood flowing backwards.Then the ventricles contracts forcing the blood to leave the heart. At the same time the atria are relaxing and once again filling with blood. The artery carry blood away from the heart. The elastic fibers allows the artery to stretch under pressure. Thick muscles and elastic fibers. The thick muscles can contracts to push the blood along. The capillaries link arteries with veins, they exchange materials between the blood and other body cells. The wall of a capillary is only one cell thick. The exchange of materials between the blood and the body can only occur through capillaries.Red Blood Cells are responsible for carrying oxygen and carbon dioxide. Red Blood Cells pick up oxygen in the lungs and transport it to all the body cells. After delivering the oxygen to the cells it gathers up the carbon dioxide(a waste gas produced as our cells are working) and transports carbon dioxide back to the lungs where it is removed from the body when we exhale(breath out). There are about 5,000,000 Red Blood Cells in ONE drop of blood.Red blood cells or a biconcave disc that is rounder and flat without a nucleus. It contains hemoglobin a molecules specially designed to hold oxygen and carry it to the cells that needed it.White Blood Cells help the body fight off germs. White Blood Cells attack and destroy germs when they enter the body. When you have an infection your body will produce more White Blood Cells to help fight an infection. Sometimes our White Blood Cells need a little help and the Doctor will prescribe an antibiotic to help our White Blood Cells fight a large scale infection. Plasma is the liquid part of the blood. Approximately half of your blood is made of plasma. The plasma carries the blood cells and other components throughout the body. Plasma is made in the liver. Platelets are bits of cells broken off larger cells. Platelets produce tiny fibrinogen fibers to form a net. this net traps other blood cells to form a blood clot. []

The Nervous System- The nervous system contains the cerebrum,cerebellum, olfactory bulb, the optic lobe, the medulla oblongata, and the spinal cord.The cerebrum has two halves, with one on either side of the head. Some scientists think that the right half helps you think about abstract things like music, colors, and shapes. The left half is said to be more analytical, helping you with math, logic, and speech. Scientists do know for sure that the right half of the cerebrum controls the left side of your body, and the left half controls the right side. The cerebrum or cortex is the largest part of the human brain, associated with higher brain function such as thought and action. The cerebral cortex is divided into four sections, called "lobes": the frontal lobe, parietal lobe, occipital lobe, and temporal lobe.The frontal lobe associated with reasoning, planning, parts of speech, movement, emotions, and problem solving. The parietal lobe associated with movement, orientation, recognition, perception of stimuli. The occipital lobe associated with visual processing. The temporal lobe associated with perception and recognition of auditory stimuli, memory, and speech.The spinal cord is a tube of neurons that runs up the spine and attaches to the brain stem. Information from nerves that branch out to the rest of the body goes to the spinal cord. Some messages are processed by the spinal cord but most information is sent on to the brain. The Locomotion System- The locomotion contains both the skeletal system and the muscular system. The locomotion system includes the axial and appendicular skeletons, cartilages, joints (ligaments), skeletal muscles, smooth muscles, cardiac muscles, and tendons. The human skeletal system accounts for about 20 percent of the body weight. Cartilage joins bones to muscles, and it acts as a shock absorber between your joints and bones and on your vertebrae. Ligament connects bones to other bones.Tendons connect muscle to bone, allowing for movement. Tendons are sometimes confused with ligaments, which attach bone to bone.Tendons can only move bone in a pulling motion. When a force is exerted on muscles, tendons respond by pulling on the corresponding bone, causing movement.The appendicular skeleton (126 bones) is formed by the pectoral girdles, the upper limbs, the pelvic girdle, and the lower limbs. Their functions are to make locomotion possible and to protect the major organs of locomotion, digestion, excretion, and reproduction. The joints between bones permit movement, some allowing a wider range of movement than other. Movement is powered by skeletal muscles, which are attached to the skeleton at various sites on bones. Muscles, bones, and joints provide the principal mechanics for movement, all coordinated by the nervous system. Most of the cell is occupied by striated, thread-like microfibers.Smooth muscle is found in the walls of hollow organs like your intestines and stomach. They work automatically without you being aware of them. Smooth muscles are involved in many 'housekeeping' functions of the body. The muscular walls of your intestines contract to push food through your body. Muscles in your bladder wall contract to expel urine from your body. Smooth muscles in a woman's uterus (or womb) help to push babies out of the body during childbirth. The pupillary sphincter muscle in your eye is a smooth muscle that shrinks the size of your pupil.Skeletal muscles cover your skeleton, giving your body its shape. They are attached to your skeleton by strong, springy tendons or are directly connected to rough patches of bone. Skeletal muscles are under voluntary control, which means you consciously control what they do.Your heart is made of cardiac muscle. This type of muscle only exists in your heart. Unlike other types of muscle, cardiac muscle never gets tired. It works automatically and constantly without ever pausing to rest. Cardiac muscle contracts to squeeze blood out of your heart, and relaxes to fill your heart with blood. []



__The Dolphins: __ Dolphins are thought to be joyful, playful creatures, but can be deadly when protecting their young. They often use their noses to, with full force, ram into sharks, repelling them from attacking their babies. The dolphin also derives strength in numbers, usually traveling in a pod of as many as 12 dolphins to provide protection and to serve the dolphin’s social needs. Super pods, which may include up to 1000 dolphins, can be found in areas where food supply is plentiful.

The Digestive System- Dolphins are fish eaters, although they are quite opportunistic and will take other available prey, such as squid and crustaceans. Most dolphins have pointed teeth to grasp, slippery fish which are swallowed whole. Some other dolphins has a few teeth in the lower jaw only, which helps it suck in and swallow squid.Dolphins swallow their pray whole or in large chunks. After swallowing the food travels down the esophagus to arrive at the stomach, a muscular sac where digestion starts. A dolphin has three compartments, it is more complex than that of other meat animals, such as humans, cats, and dogs. These types of animals only have one. Muscular churning in the first part of the dolphins stomach, the fore stomach grinds up the food. This process is called mechanical digestion. the resulting mush called chyme it squirted into the second chamber, the main stomach where chemical digestion begins. The walls of the main stomach secrete hydrochloric acid to reduces the pH and protein- digesting enzymes, more protein digesting enzymes to chemically break down the food. The walls of the third stomach, secrete fat-digesting enzymes. more protein digesting enzymes, and an alkaline fluid that neutralizes the acidity of the main stomach juices. The partly digestive food now enters a short tube called the duodenum, the first part of the small intestine. The pancreatic duct and the bile duct empty their contents into this organ. Pancreatic juices contains a mixture of digestive enzymes for different food types- proteins, fats, and carbohydrates. Bile is a liquid that contains bile salts, they break up globes of fats making them smaller and easier to digest. Futher chemical digestion takes place in the final section of the small intestine, the ilem the walls of which realeases more digestive enzymes, water and digested food are absorbed in the larges intestines, which follows the small intestine, the rectum before being expelled through the anus. The kidneys removes excess salt from the blood stream along with the by-products of cellular activity and other wastes. The kidneys filters the blood reabsorbs what is useful and allows the rest to pass out the body in urine.

The Respiratory System- Dolphins, like other mammals, need air to survive, especially oxygen. Oxygen is one of the main sources of energy in the body and every living thing cannot do without it. Unlike fish, dolphins have to rise to the surface frequently to breathe. When they are underwater, they hold their breath; when they are out of breath, they return to the surface to take in more fresh air.Unlike other mammals who breathe through their nostrils and mouth, dolphins breathe through the blowhole, which is situated on the top on its head. A reason for this difference is that the blowhole will facilitate the breathing at the surface of the water. Since the blowhole is at the top of the head, only a small region of the head is required to break the surface of the water to inhale air. The dolphin starts to exhale before reaching the surface and this helps to reduce the amount of time spent breathing at the surface. Dolphins can catch a breath about five times in a minute before diving again, without hindering the progress of their swim. Usually, a dolphin breathes two to four times each minute when it is swimming near the surface. It can hold its breath for seven minutes or more when it is diving.The lungs of dolphins are not significantly larger or smaller than the land mammals. Obviously, the size of the lungs does not determine the amount of oxygen that can be stored and utilized.However, the dolphin lungs contain a lot more alveoli (air cells) than human lungs do. Dolphin lungs are made up of two layers of capillaries, and this arrangement increases the efficiency of gas exchange since most mammals have only one layer of capillary. Therefore, this means that the surface area of the lungs have been greatly increased and gas exchange can occur more quickly.The pleurae of dolphins are thick and elastic. The pulmonary tissue proper contains a generous supply of myoelastic fibers for better elasticity. The bronchial tubes are lined with muscular tissue. Tiny bronchioles are found together with sphincters that cut off the alveoli from the rest of the lung. The respiratory system of dolphins certainly has some unusual features, but they are adaptations to prevent water entering the airways: the nasal passages are complex and convoluted, and the larynx (the upper end of the respiratory tube) extends up into the nasal cavity rather than opening into the throat. Powerful muscles form a special plug within the blowhole, preventing water from entering the lungs when the dolphin is underwater. [|http://understanddolphins.tripod.com/dolphinblowholeandbreathing.html]

The Excretory System- The excretory system contains kidneys.The kidneys of a dolphin are large, consisting of numerous interconnected and closely packed lobes called "renculi". Similar forms of renculi have been found in other marine animals but there is yet a known reason for the existence of this structure. There is a possibility that the presence of these lobate kidneys is part of the adaptation of the dolphins' underwater life.Dolphins have to obtain their supply of water despite living in the sea as the water in the sea is saline and not suitable for consumption. Dolphins get most of the fresh water they need by eating fish. The kidneys are not very specialized in desalinating water. Instead, the dolphin's skin does most of the job by acting as an osmostic membrane, allowing only water but not salt to enter its system. However, the dolphin's kidneys are not entirely useless - they contain special structures which may aid with filtration during diving. []

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The Circulatory System- Although the circulatory systems of marine mammals follow the general mammalian plan, they are most notable for features associated with the diving response, thermoregulation, and large body mass. Specific features of the circulatory system vary with orders, families, and species (we're now talking about not just cetaceans but pinnipeds as well in this case and for just a little to follow). These adaptations include large blood volumes, large capacitance structures (spleens and venous sinsuses), venous sphincter muscles, vascular adaptations for thermoregulation, aortic windkesssels, and vascular retia. The basic structure and size of hearts in cetaceans are typical of mammals. The four-chambered heart with right ventricular outflow to the lungs and left ventricular output to the systemic circulation, weighs 0.5-1.0% of body mass in most small cetaceans (dolphins). Both the foramen ovale and the ductus arteriosus are closed in adult cetaceans as in other mammals. In my opinion, the absolute coolest thing about the circulatory system of dolphins and whales is the rete mirable (or retia mirabilia), the parallel pattern of counterflowing arteries and veins, present in the flukes and flippers of cetaceans. Countercurrent anatomy is even in the reproductive organs of these animals! http://7hills-mrberning.wikispaces.com/DOLPHIN+Circulatory+System The Nervous System- Comparisons of mammal brains are described as the ratio of brain size relative to body size. Bottlenose dolphin brains are larger than many other mammals of the same body size. Scientists are still determining what aquatic adaptations require the large brain size. One likely theory is that a larger brain size in dolphins may be at least partially due to an increased size of the auditory region to facilitate sound processing. Hypotheses that large brain size in dolphins indicates high intelligence are untested and disputed. The ability of an animal to process information is based upon its brain anatomy as well as the specific experiences the animal has. Rating the intelligence of different animals is misleading and extremely subjective. In fact, a reliable and consistent intelligence test for humans has yet to be developed. It would be improper to attempt to quantify or qualify the intelligence of animals using only human guidelines. The dolphin's auditory nerve is about twice the diameter of the human eighth nerve (connecting the inner ear to the brainstem) leading to more rapid sound processing for dolphins. In addition, a dolphin's auditory nerve supply is about three times that of humans—possibly providing more ultrasonic information to a dolphin's central nervous system for echolocation. Bottlenose dolphins hear tones with a frequency up to 160 kHz with the greatest sensitivity ranging from 40 to 100 kHz. The average hearing range for humans is about 0.02 to 20 kHz. In dolphins, ears aren't attached to the skull. Ligaments hold each ear in a foam-filled cavity outside the skull. This separation of the ears allows a dolphin to localize sound, which is important for echolocation. Humans and most land mammals cannot effectively localize sounds under water. []

Locomotion- The backbone is very flexible, due to the reduced interlocking of individual vertebrae and the development of large fibrous discs between them, to allow powerful undulations of the tail for swimming. The cervical vertebrae are shortened, the seven neck vertebrae have become greatly compressed, and some or all of them fused, making the neck short and rigid. This would mean that most dolphins can only move their from side to side, and not nod up and down. The front limbs have evolved into flippers so as to minimise resistance in the water. The flippers are generally more rigid than the mammalian hand because the only mobile joint is the shoulder. The typical structure of the mammalian hand is still present in the skeleton, despite its hydrodynamic function. However, the fingers have become lengthened, thus increasing the surface area. The individual bones of fingers (known as the phalanges) are generally increased beyond the normal mammalian number but the number of fingers are reduced to four. The skull of the dolphin has departed from the normal mammalian structure by being 'telescoped', which allows the face bones to elongate greatly, therefore meaning that both the upper and lower jaws are unusually long. This can be done by compressing from front to back of the skull so that certain parts overlap each other - like the sections of a folded up telescope). The skull has become tilted upwards in line with the spinal column and the cervical vertebrae (the neck) have become fused together in all species. The main bones of the upper jaw have been thrust backwards and upwards over the eye sockets to extend across the front of the brain-case. This type of telescoping of the upper jaw may be associated with the well-known ability of dolphins to echolocate or use sonar. Other aspects of the skulls of dolphins also seem to be adapted for producing and receiving high-frequency sounds. The expanded and backward-shifted upper jaw bones hold a large volume of facial muscles, and these muscles focus upwards and in towards the blowhole. At the blowhole, the muscles are attached to a series of sacs in the soft tissues of the nasal passages between the external blowhole and the bony nasal openings on the skull. In each ear, the middle ear cavity is expanded into a complex sinus on the skull base. These sinuses help to isolate the right and left ears from each other, making it easier for the animal to tell the direction of a sound source. The periotic, the earbone that carries the organs of hearing and balance, is not fixed to the skull in dolphins. The external ear canal is vestigal. Sound is perhaps transmitted from the water to the internally placed ear boens via a thin 'pan-bone' in the lower jaw and a fatty channel from the pan-bone. []

Taxonomy Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Cetacea Family: Delphinidae Genus: Tursiops Species: truncatus []

Ecology: Variations in water temperature, movements of food fish, and feeding habits may account for the seasonal movements of some dolphins to and from certain areas.Some coastal dolphins in higher latitudes show a clear tendency toward seasonal migrations, traveling farther south in the winter. For example, coastal bottlenose dolphins on the Atlantic side of the U.S. migrate seasonally between New Jersey and North Carolina.Coastal dolphins in warmer waters show less extensive, localized seasonal movements.Some coastal animals stay within a limited home range: an area in which individuals or groups regularly move about during day-to-day activities.Individual dolphins that live within a home range are called "local residents." Resident dolphins have been identified along the coasts of Georgia, Florida, Texas, southern California, Gulf of California, and South AfricaGroups of dolphins that reside within a home range make up "resident communities." The Sarasota, Florida resident dolphin community home range is an area of about 125 km2 (48.3 mi2).Home ranges may overlap. Bottlenose dolphins live in a variety of habitats, from coastal waters to the open ocean.Scientists recognize two bottlenose dolphin ecotypes(forms): coastal and offshore. In the northwest Atlantic, bottlenose dolphin coastal and offshore ecotypes can be differentiated by skull and body measurements as well as by characteristics of their blood.In general, the coastal ecotype seems to be adapted for warm, shallow waters. Its smaller body and larger flippers suggest increased maneuverability and heat dissipation. These dolphins frequent harbors, bays, lagoons, and estuaries.In general, the offshore ecotype seems to be adapted for cooler, deeper waters. Certain characteristics of its blood indicate that this form may be better suited for deep diving. Its larger body helps to conserve heat and defend itself against predators.In northwest Atlantic bottlenose dolphin studies, researchers determined that dolphins within 7.5 km (4.65 mi) of shore were coastal ecotypes. Dolphins beyond 34 km (21 mi) from shore were offshore ecotypes. Bottlenose dolphins are not endangered.The worldwide population of bottlenose dolphins is unknown. Specific bottlenose dolphin populations in a few areas have been estimated.U.S. National Marine Fisheries Service (NMFS) surveys estimate 243,500 bottlenose dolphins in the eastern tropical Pacific.Japanese surveys estimate 316,935 dolphins in the northwest Pacific.NMFS surveys in the northern Gulf of Mexico estimate as many as 45,000 bottlenose dolphins from the coast to about 250 km (155 mi.) offshore. This area includes the Gulf's bays and sounds, coastal waters (about 17,600 individuals), and continental shelf waters (about 25,320 individuals).In U.S. waters of the western North Atlantic, average abundance estimates for the coastal population are 9,206 from the summer survey and 19,459 from the winter survey. The western North Atlantic average abundance estimate for the offshore population is 29,774 individuals.The Mediterranean population is estimated at less than 10,000.Average abundance estimates for the U.S. west coast include the California coastal population of 206 individuals and the California-Oregon-Washington offshore population of 5,065 individuals.Chromosome banding techniques have proven useful in bottlenose dolphin population studies. In some areas, scientists can identify individuals and determine relationships among dolphins in a group. Dolphins food chains starts from the sun, then the seaweed grows and the small fish eat it, the big fish eats them, then the dolphin eats the big fish, and finally the shark eats the dolphin and the killer whale eats the shark.Dolphin calves stop drinking their mother’s milk at 6 months of age.The fish that they eat include squids and crustaceans, such as shrimp.Adult dolphins eat up to 4% to 5% of their body weight per day, but a nursing mother may eat up to 8% per day. Dolphins’ teeth are usually made for grasping not chewing. If a dolphin needs to break its food into smaller pieces, it will grasp its food and throw it against the water. This makes it easier to eat the food. Dolphins do not chew their food. They swallow it whole. They swallow fish head first so that the spines of the fish won't catch in their throats. Mating Behavior- A dolphin's sexual maturity is reached when the dolphin becomes old enough to reproduce. It is generally thought that female Dolphins reach sexual maturity between five and twelve years old male Dolphins reach sexual maturity when they are ten to twelve years old.Females usually initiate the courtship and breeding behavior.This breeding behavior occurs throughout the year. Once courtship is initiated the gestation period begins which lasts for ten to twelve months. Only one calf is born at a time but a female bears a calf about every three years.A calf is born either head-first or tail-first. Right after delivery the dolphin calf swims to the surface for its first breath of air. The dolphin new born calf is usually between forty-two to fifty-two inches long and weighs about forty-four pounds. Males and females mate belly to belly, and both sexes may have multiple partners over their lifetime. In Sarasota Bay, it is common for a female’s sequential young to have different fathers.Genetic and behavioral data gathered from many studies over the years suggest that the bottlenose dolphin has a polygynous mating system in which males compete with one another for access to females, and a relatively small number of dominating males may sire most of the young.Competition between males may be through direct physical contact, such as by blows of the peduncle and fluke of one animal to the body of another. Competition can also be indirect, such as when a male protectively herds a group of females in a way that excludes access by other males. The moderate expression of size-related sexual dimor- phism in this species supports the idea that males compete with one another for dispersed females rather than monopolizing access to aggregations females. If the latter were the case, we would expect males to be much larger than females.

<span style="color: #18c45e; font-family: Impact,Charcoal,sans-serif; font-size: 190%;">Dolphins Facts

1. Dolphins are mammals - As all mammals, dolphins nurse their young from mammary glands. 2. Dolphins can swim up to 260 m. below the surface of the ocean - However they are mainly shallow divers as they need to reach the surface to breathe. 3. Dolphins can stay up to 15 minutes under water - They only do this some times as they usually stay only a few minutes diving before reaching the surface for air. 4. Dolphins use a technique called echolocation - This technique uses the same principles of a radar, and it is used to find food and navigate. 5. Dolphins are social beings-Dolphins live in groups and cooperate among each other for activities like getting food and calf rising. 6. Dolphins are Cetacenas - There are 32 species of ocean dolphins and 5 species of river dolphins. 7. The largest dolphin is the Orca, also known as“killer whale”- Orcas grow up to 6.1 meters long and they are named as whales because their size, but they really belong to the toothed cetacean family just like dolphins do. 8. The most popular dolphin is the “bottlenose dolphin" - Bottlenose dolphins are the ones we have seen in tv series, movies and aquatic shows. Bottlenose dolphins can grow up to 2.5-2.8 meters. 9. Dolphins are warm-blooded - As mammals, dolphins are warm blooded and their internal temperature is around 36 degrees. To conserve this temperature they are surrounded by a thick layer of fat called “blubber” just below the skin.  10. The botllenose dolphin brain weighs 1500-1600 grams- While average human brain weighs 1200-1300 grs. This is not a conclusive evidence of dolphin intelligence as many other factors might be the cause of intelligence according to scientists.  11. Dolphins communicate efficiently.Dolphins can make a unique signature whistle that may help individual dolphins recognize each other, collaborate and perform several other kinds of communication.  12. Dolphins can swim 5 to 12 kilometers per hour-This will depend on the species and situation, although fastest dolphins can reach up to 32 km/h.