Shark vs Whale
Sharks and whales are the big bosses of the sea, and they are excellent predators with enormous bodies. There are a lot of interesting facts about them. These two thrilling beasts have been studied well, and this article intends to discuss their differences and similarities related with their biology. Sharks sound more dangerous, and whales enormous however, whale shark is a filter feeder while killer whale is a dangerous predator. Therefore, it is important to be aware of these two interesting animals.
Shark
Sharks are predatory fish with streamlined bodies adapted for fast swimming. They have cartilaginous internal skeletons and belong in the Class: Chondreicthyes. A shark’s gills are not covered by an operculum, which is a notable feature. Their teeth are not attached to jaws but arranged in rows which are embedded in the gum. Their skeleton is made up of cartilages and connective tissue, but not bones. Also, sharks do not have a rib cage as in most of the vertebrates. The shape of the caudal fin differs within species. They don’t have gas filled swim bladder instead an oil filled liver and the low weight skeleton are useful for their buoyancy in the water column. Sharks are cold-blooded animals but, they are able to keep warmer blood around eyes and brain through circulatory mechanisms. Since, their blood and tissues are isotonic to the highly saline sea water hence, the osmotic pressure is balanced. Their digestion is different from the other fish as the food is stored in the stomach and unwanted materials are thrown out through mouth by turning the stomach inside out. Sharks have an excellent sense of smell and a good vision. Additionally, they are electro receptive and they can also sense the environment from their lateral line. They are solitary hunters and can swim about eight kilometres without resting at a higher speed. They sleep by lying on the seabed, but the eyes kept open. Usually, a shark lives about 20 to 30 years.
Whale
Whales are gigantic marine mammals of Order: Cetacea. The blue whale is the largest animal on the Earth. Being mammals, they are warm-blooded. They nourish their young with nutritious milk produced in mammary glands. Their skin is covered by hair and there is a fat layer beneath the skin functioning in thermoregulation, buoyancy, and as an energy store. Whales have a four chambered heart and they breathe through blow holes. Interestingly, males are called bulls and females called cows. The other important feature is that whales take rests but they never sleep. They could be either predators (e.g. Killer whale) or filter feeders. Whales are long lived mammals with a lifespan of 70 – 100 years.
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Differences between Shark and Whale • Sharks are fish and cold-blooded, whereas whales are warm-blooded mammals. • Sharks have a cartilaginous skeleton, but it is a bony skeleton in whales. • Whales are generally larger in body size than sharks. • Whales have lungs sharks have gills for breathing. • The body of the whale is covered with hair but shark has dermal denticles covering the skin. • The teeth are fixed in the dental arch in whales, whereas sharks have teeth arranged in rows and fixed in the gum. • Sharks sleep, but whales only rest. • Whales nourish the newborns by milk secreted by mammary glands, but sharks do not. • Whales have thick fat layer beneath the skin, but sharks have oil-filled liver for buoyancy. • Whales live longer than sharks. • The whales have developed ears, but sharks have excellent senses of smell, vision, and electro receptiveness.
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