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What makes a fish a fish? What's the biggest shark? What's the smallest shark? What's the average size of all sharks? How many species of sharks are there? What animal poses the greatest threat to sharks? What makes a shark's, skate's, or stingray's skeleton different from the skeletons of all other fishes? Which came first - sharks or dinosaurs? How many kinds of freshwater sharks are there? How many people do sharks attack each year? Why do most sharks need to swim constantly? What is your oldest fish? Are all eels electric? Do fishes sleep? Why doesn't Shedd have great white sharks?  What makes a fish a fish?
Several characteristics make a fish a fish. These include a spine, scales, fins, gills, lateral lines, air bladder and cold-bloodedness. Not all fishes have all characteristics; for example the moray eel has no scales, but it is still a fish. The shark has no air bladder, but it is still a fish.What's the biggest shark?
The biggest shark is the whale shark, Rhincodon typus. The greatest recorded length is 60'9" and weight is 90,000 pounds.top What's the smallest shark?
There is some debate, but the generally accepted "smallest shark" is the spined pygmy shark, Squaliolus laticaudus. It reaches a size of only 6 inches at maturity. Other small sharks are the cigar shark, Isistuis brasiliensis, 20 inches at maturity; and the pygmy ribbon catshark, Eridacnis radcliffei, 9.45 inches at maturity.top What's the average size of all sharks?
More than 50 percent of known shark species are less than 3 feet long.top How many species of sharks are there?
There are approximately 375 known species. New shark species are being discovered all the time.top What animal poses the greatest threat to sharks?
Humans.top What makes a shark's, skate's, or stingray's skeleton different from the skeletons of all other fishes?
Their skeletons are cartilaginous instead of bony. They make up the class Chondrichthyes.top Which came first - sharks or dinosaurs?
There are fossil records of sharks as far back as 400 million years ago. Dinosaurs were on the Earth 240 million years ago.top How many kinds of freshwater sharks are there?
Sharks are found only in marine (saltwater) environments. There is one shark, the bull or zambizi shark, that has been found in freshwater rivers, but that is not its primary habitat.top How many people do sharks attack each year?
Each year, sharks attack approximately 75 to 100 people. Only about 15 attacks a year are fatal.top Why do most sharks need to swim constantly?
Sharks lack a swim bladder, the organ found in most other fishes to help them keep afloat. If a shark stops swimming, it will start to sink to the bottom. Once a shark has landed on the bottom, it is no longer pumping water through its gills. Without this water, the shark cannot get the oxygen it needs for respiration. Interestingly, a shark gets much of its buoyancy from its liver. There are some sharks, however, that do not need to keep swimming. The nurse shark is an example. It can actively pump water through its gills so it can rest at the bottom of the water and still breathe.top What is your oldest fish?
The oldest fish at Shedd Aquarium is an Australian lungfish. It arrived at Shedd in 1933.top Are all eels electric?
No, in fact, no eels are electric. There is an animal called an "electric eel," but it is not really an eel. It does not belong to the eel order, Anguilliformes. The electric eel is a fish that does generate electricity using a series of electric organs located throughout its body. Moray eels do not generate electricity.top Do fishes sleep?
Some do. For example, the parrotfish sleeps inside a mucous cocoon it makes every night. This blocks its scent from nocturnal predators that might want to eat the parrotfish while it sleeps. Some fishes burrow in the substrate or hide in crevices to rest. Other fishes can't sleep - they need to keep swimming in order to breathe. Sharks and tuna are among the fishes that can't sleep.top Why doesn't Shedd have great white sharks?
Most sharks need to keep swimming in order to pump water through their gills. We don't have enough space to ensure the safety and comfort of a shark the size of a great white.top |
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