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In fish, the long bony cover for the gill (the operculum) can be used for pushing water. Some fish pump water using the operculum. Without an operculum, other methods, such as ram ventilation, are required. Some species of sharks use this system. When they swim, water flows into the mouth and across the gills.
The body of a fish is denser than water, so fish must compensate for the difference or they will sink. Many bony fishes have an internal organ called a swim bladder, or gas bladder, that adjusts their buoyancy through manipulation of gases. In this way, fish can stay at the current water depth, or ascend or descend without having to waste ...
Fish gills are organs that allow fish to breathe underwater. Most fish exchange gases like oxygen and carbon dioxide using gills that are protected under gill covers (operculum) on both sides of the pharynx (throat). Gills are tissues that are like short threads, protein structures called filaments. These filaments have many functions including ...
The density of the water prevents the gills from collapsing and lying on top of each other; [such collapse] happens when a fish is taken out of water." [ 4 ] Usually water is moved across the gills in one direction by the current, by the motion of the animal through the water, by the beating of cilia or other appendages, or by means of a ...
The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ in bony fish (but not cartilaginous fish [1]) that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift via swimming, which expends more energy. [2]
What level of pain do fish feel? That, too, is unknown. Zangroniz said studies only use a few species of fish and don't represent the more than 30,000 fish species that exist. She added pain is ...
These electric fields are generated by all animals due to the activity of their nerves and muscles. A second source of electric fields in fish is the ion pump associated with osmoregulation at the gill membrane. This field is modulated by the opening and closing of the mouth and gill slits.
A fish's hypoxia tolerance can be represented in different ways. A commonly used representation is the critical O 2 tension (P crit), which is the lowest water O 2 tension (P O 2) at which a fish can maintain a stable O 2 consumption rate (M O 2). [2] A fish with a lower P crit is therefore thought to be more hypoxia-tolerant than a fish with a ...