1. Size and Shape:
* Sharks: Have a larger, more prominent liver that often occupies a significant portion of the body cavity. The liver is typically shaped like a "Y" with two large lobes extending along the body and a smaller lobe in the middle.
* Bony Fishes: Possess a smaller liver that is usually more compact and elongated.
2. Composition:
* Sharks: Their livers are rich in lipids, primarily squalene, a hydrocarbon that is lighter than water. This large lipid reserve provides the main source of buoyancy for sharks.
* Bony Fishes: Have a lower lipid content compared to sharks. They rely primarily on swim bladders for buoyancy.
3. Function:
* Sharks: The liver plays a dominant role in buoyancy control. Squalene's low density allows sharks to stay afloat with minimal effort. Their livers also store energy and vitamins and aid in detoxification.
* Bony Fishes: Their livers are involved in energy storage, detoxification, and synthesis of proteins but contribute less to buoyancy.
4. Other Features:
* Sharks: The liver in sharks has a unique venous portal system, which allows for efficient transport of nutrients and waste products.
* Bony Fishes: May have specialized lobes within their livers for specific functions like fat storage or detoxification.
In summary, the liver of sharks is significantly larger and richer in lipids compared to bony fishes, reflecting their dependence on this organ for buoyancy control. Bony fishes rely more on swim bladders for buoyancy and have a smaller, less lipid-rich liver.