How Many Chambers are There in Fish Heart

Introduction about Heart

The heart is typically a muscular organ in animals. This organ pumps blood through the blood vessels of the circulatory system. The blood that is pumped around the body carries nutrients and oxygen to the body while transporting metabolic waste, like carbon dioxide, to the lungs. The human heart is situated in the middle of the chest, between the lungs, and is roughly the size of a closed fist.

Chambers of Heart

The chambers of the heart known as the Atrium/Auricle, and Ventricle are actually divisions of space within the heart separated by a muscular wall known as the septum (plural: septa). Their primary function is to prevent the mixing of pure (oxygenated) and impure (deoxygenated) blood. The number of chambers in the heart varies among organisms. Hearts of birds and mammals have two atria and two ventricles, making up their four chambers. Fish have two chambers in their hearts (one atrium and one ventricle), whereas frogs, which are amphibians, have three chambers (one ventricle and two atria) in their hearts. Three hearts make up an octopus's heart system, with the main heart (H1) pumping blood to the body and the other two (H2 and H3) pumping blood to the gills. In cockroaches, the heart has 16 chambers. Leeches are said to have 32 chambered hearts.

Heart in Fishes

Although a fish's heart is typically believed to have two chambers, its shape is quite different; it has distinct entry and exit areas, leading us to frequently refer to it as a three- or four-chambered heart. In fish, the systemic heart is made up of four chambers: the sinus venosus, atrium, ventricle, and conus or bulbus. All chambers of the heart, with the exception of the bulbus, contract to maintain unidirectional blood flow through the organ. The distribution of spontaneously active cells, the speed and nature of excitatory wave spread, and the characteristics of resting and action potentials may differ slightly between different fish and other vertebrates. The heart is made of typical vertebrate cardiac muscle. Only hagfish have aneural hearts; in all other species, the heart is innervated by cholinergic fibres.

There is no sympathetic innervation in fish hearts. The vagal tone, which varies greatly, is influenced by a number of factors. Some fish develop essentially aneural hearts (vagal tone is absent) that resemble isolated mammalian ventricles under stress. These hearts have increased cardiac output and venous return. Fish hearts have been found to contain R-adrenergic receptors, and variations in catecholamine levels may have an effect on how the heart's activity is perceived. Fish typically show changes in cardiac output along with large variations in stroke volume and small variations in heart rate output. A fish's heart varies from species to species in terms of shape and number of chambers.

Functions

The fish heart works similarly as a vertebrate heart, and the primary function of pumping blood is as it is. However, some fishes have specialised hearts that may be used for various functions, like in frogfish, which is a deep water fish of marine water, the heart helps in creating sonic vibrations that can be reported as grunting sound, this is done in order to communicate in groups as well as to assign territorial boundaries. In some fishes like Salmons the heart is able to create increased blood flow for a period of time that can be used to create exceptional movement in the body, as salmons has to go upwards in the opposite direction of stream and gravity, to lay their eggs, they use this ability to jump and cross heights. In archer fishes, these fishes use the relaxation of heart as a trigger for shooting a jet of water through their mouth, which helps them in taking down bugs that are way up in trees. The fill their air bladders with air, and a sudden expansion of the heart creates enough pressure to shoot a water bullet out of their mouths. This is also the reason that they are called archer fish.

Conclusion

In Fishes there is believed to be a two-chambered heart, but through scientific studies it is stated that the number of chamber in a fish heart along with its structure, varies from species to species, it can be two-chambered, three-chambered as well as it can be four-chambered,