Those that can are mostly members of one of the eel families. Sustained swimming speeds generally range from about 5 to 10 miles per hour among strong swimmers.Ī number of fish species can swim backwards, but usually don't. They can reach 50 miles per hour in short bursts.
Tunas and tuna-like fish, billfish, and certain sharks are the speed champions. Sometimes fish might use them to aid rapid forward motion. Paired pectoral and pelvic fins are used primarily for stability when a fish hovers. Vertical fins are used mainly for stabilization. This whips the tail very rapidly from side to side in a sculling motion. Lined seahorse swimming in vertical positionįish swim primarily by contracting bands of muscles in sequence on alternate sides of the body. They are still alert for danger, but they are also "sleeping." How do fish swim? Some float in place, some wedge themselves into a spot in the mud or the coral, some even build themselves a nest. Also, a great many fish live nearly motionless lives. Most fish don't have eyelids (except for sharks). The dictionary defines sleep as a recurrent period of rest in which the nervous system is inactive, the eyes closed. Their gills contain a network of fine blood vessels that diffuse the oxygen throughout the fish's membranes. Do fish breathe air?įish breathe oxygen, not air. How long a fish lives depends on its species. In the Northwest Atlantic, the longest-lived fish is the Acadian redfish, which can live past 40 years. The orange roughy lives more than 100 years.
In summer the rings are wider apart. In winter the rings are closer together, because the fish grow more slowly.
Cool freshwater fish series#
In scales, a series of fine rings appear as the scale grows. The summer ring is whiter and the winter ring is thinner and more translucent. Otoliths grow like pearls, but the added material changes color depending on the season. Scientists can figure out how old a fish is by counting growth rings on its scales or its ear bones (called "otoliths"). The rings mark seasonal changes in fish growth, like the annual rings in tree trunks. Zoologists study these bottom-dwelling fish because some parts of their bodies can help to explain evolution from low to advanced life forms.īluefish otoliths How can you tell a fish's age? They stopped evolving before the development of biting jaws. The oldest fish-like animals are those with sucking mouths, like lampreys and hagfish. It is caught at 500 meters or deeper all over the world. The most common fish is any of the species of a deepwater fish sometimes called a "bristle mouth." The fish is about the size of a small minnow. What's the most common fish in the ocean? It rarely grows longer than half an inch at adulthood, yet is so abundant it supports a fishery. The smallest fish is the tiny goby, which lives in the Philippines.
Specifically, the whale shark, which grows to more than 50 feet long and may weigh several tons. The second largest is the basking shark, which can measure 35 to 40 feet long.
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