0
Bony fishes achieve buoyancy through an air filled sac called a swim bladder. The bladder controls the fish's buoyancy by varying the gas pressure inside the fish's body to allow it to sink or rise in the water.
Chondrichthys, or cartilaginous fishes (sharks, skates, rays) achieve buoyancy in other ways because they do not have swim bladders. They do this 3 ways:
1. Store low-density compounds in the body. They store various lipids in throughout their bodies ,which have lower densities than seawater. Squalene is one lipid that is stored in the liver of sharks.
2. Reduction of dense tissues. Chondrichthys do not have replaced bones with cartilage, which helps them reduce their weight in the water. Cartilage is 1/2 as dense as bone. They also reduce muscle mass and protein content. They also increase water content of tissues .
3. Dynamic lift. Sharks can generate lift by their swimming motion. They have a heterocercal tail with a larger dorsal lobe than the ventral lobe. This tail generates lift on the posterior end of the fish, but pushes the anterior end down. This is corrected by having large pectoral fins. This positive attack angle generates head lift. The head of a shark is also flattened dorsoventrally and counteracts the tendency for the tail to push the head downward.
The disadvantage of the Chondrichthys methods of buoyancy is that it is difficult for them to adjust their buoyancy and low density lipids are energetically expensive to make. Dynamic lift requires constant forward motion. They must keep swimming, which can also cost a lot of energy.
Wiki User
∙ 14y ago
Wiki User
∙ 13y agoSharks for example that do not posess a swim bladder for buoyancy like many bony fishes have, must depend upon their livers. The liver contains squalene which is an organic compound that is lighter than water. The liver takes up 30% of the sharks body mass, but it is limited in use. The shark basically has to keep moving to live with it's fins. Some sharks though store air in their stomachs acting as a swim bladder to stay motionless. Also some sharks can pump water across their gills to allow them to rest at the bottom.
no one
Fish manage to stay upright because of their equally distributed body mass and the hydrodynamics of their fins;also partially in the aero dynamics of their bulet-shaped or flat bodies. Whereas making it easier tobalance and glide through thewater and currant.^^
Wiki User
∙ 14y agoA fish is buoyant because it has a blader.
Wiki User
∙ 10y agoThe fins of the fish help the fish stay upright in the water, as it is swimming.
Wiki User
∙ 16y agotheir bladder.
Add your answer:
Earn +20 pts
How do fish stay afloat?
by farting gas !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
What are the differences between jaw less fish and cartilaginous fish?
Jawless fish and cartilaginous fish have cartilaginous skeletons, and bony fish have skeletons made from bone. Cartilaginous fish and bony fish both have jaws, paired appendages, and whole vertebrae, and jawless fish lack jaws, paired appendages, and often are without whole vertebrae. Cartilaginous fish can have scales or be naked, jawless fish are naked, and bony fish have scales. Bony fish have swim bladders, and cartilaginous fish do not. Jawless fish, cartilaginous fish, and bony fish all have fins, gills, and dorsal nerve cords that lead to a distinct brain. They all also have postanal tails and notochords.
An example of a cartilaginous fish?
Cartilaginous fish such as sharks, skates, and rays are vertebrates, whose internal skeleton is made entirely of cartilage and contains no ossified bone. Cartilaginous fish are also known as Chondrichthyes and have one or two dorsal fins, a caudal fin, an anal fin, and ventral fins which are supported by girdles of the internal skeleton.
Cartilaginous fish conduct what?
internal fertalization
Among jawed fish you have your bony fish and your cartilaginous fish Which of these is one of the latter?
Shark
Which fish can stay underwater the longest cartilaginous or bony fish?
it is the cartilaginous fish.s
How do fish stay afloat?
by farting gas !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Is a tuna fish cartilaginous fish?
no. cartilaginous fishes are sharks and rays.
Do cartilaginous fish have operculum?
Jawless fish are cartilaginous, but they do not have jaws. Class Chondrichthyes, which contains most cartilaginous fish, like sharks, have powerful jaws.
Are skates cartilaginous fish or bony fish?
Similar to Stingrays, skates are cartilaginous.
What do crocodiles eat to stay afloat?
they eat small mammals,fish,crabs,frogs and birds
Like jawless fish cartilaginous fish have sketetons made of?
Both jawless fish and cartilaginous fish have skeletons made of cartilage.
How does the air bladder work for the fish?
no, they have a swim bladder but this is so the fish can stay afloat
What are the differences between jaw less fish and cartilaginous fish?
Jawless fish and cartilaginous fish have cartilaginous skeletons, and bony fish have skeletons made from bone. Cartilaginous fish and bony fish both have jaws, paired appendages, and whole vertebrae, and jawless fish lack jaws, paired appendages, and often are without whole vertebrae. Cartilaginous fish can have scales or be naked, jawless fish are naked, and bony fish have scales. Bony fish have swim bladders, and cartilaginous fish do not. Jawless fish, cartilaginous fish, and bony fish all have fins, gills, and dorsal nerve cords that lead to a distinct brain. They all also have postanal tails and notochords.
What class of fish do sharks belong to?
Sharks belong to cartilaginous fish. (Chondrichthyes)
Is lizard bony or cartilaginous?
Lizards are not bony or cartilaginous fish, they are reptiles.
What does cartilaginous mean?
Cartilaginous fish have cartilaginous endoskeletons, meaning their skeletons are made from cartilage. Cartilaginous fish can also have placoid scales, or they are naked. Cartilaginous fish have gills, paired appendages, strong jaws, notochords, a dorsal nerve chord that leads to a distinct brain, and lack a swim bladder.
