Like breathing fish in water?Very interesting question, I answer it is not difficult.She breathes with gills, but exactly how it happens, because the water - it's not the air?And if the fish have gills?And if they can breathe atmospheric air?And how do they get the oxygen out of the water?So many questions arise at once, if only to think about how you can breathe in the water.We try to find the answers.
Respiratory fish
main respiratory organs are gills of fish.They are located near the head of the gill cavity.It paired organ.In addition, they are very gentle, so to protect their gill lid covers the top.But if the gills have the same structure?Of course not.Different groups of fish is different.For example, Cyclostomata saccate gills, while the cartilage, such as sharks, they plate.And here at the largest group - bony fish - gills comb.They have a very complex structure.Also very interesting fact: in contrast to all other bony fishes "breathe" through the mouth.But in cyclostomes hagfish and cartilaginous rays water with oxygen supplied from the outside.In the evolution of respiratory organs of fish has become increasingly complex and advanced.Most fish breathe oxygen dissolved in the water, but there are exceptions, the ones that are used, and air.
lungfish lungfish
breathe the same way as all the other species.But there are another interesting feature.This very ancient group of fish is not just gill, but also pulmonary respiration.Once these species have been widely distributed in the world.Now there is only one unit - rogozuboobraznye.They are found in Australia, Africa and South America.As for the implementation of pulmonary respiration these fish have one or two (depending on species) bladder.They are located on the ventral side of the esophagus.This allows lungfish long time to be in the oxygen-depleted waters, where other fish simply can not survive.
Respiratory Cyclostomata
In the early days of fish, perhaps the first one developed, albeit not the most sophisticated, yet the gills are Cyclostomes.It's not even really a fish.Minogovye (cyclostomes) appeared much earlier and are separate detachment jawless.Their respiratory presented gill bags.They have an endodermal origin and arose as a result of separation from the pharynx.As lamprey fish breathes through them?She has seven pairs of gill bags, each of them on two holes.The first is called the outer, and the second - an internal, it leads to a breathing tube.In addition, this hole can be constantly opened and closed.The very breathing tube formed by dividing the pharynx.The upper part of the digestive began, and the lower - respiratory.Most minogovyh external gill openings are combined into one channel.It opens a little further the last gill bag.In lampreys and hagfish nostril connected to the pharynx.Therefore, even when the fish buries in the sand, it can breathe.When Cyclostomes feed, the water penetrates the gill bags not through the oral or nasal cavity and through the outer gill holes.
structure of the gill apparatus
teleost bony fish breathe with gills.They have a complex structure.So branchial apparatus consists of five gill arches.They are in a special cavity of the head.In order to protect the arc from mechanical damage, they top covers solid and strong gill lid.It grows larger fish size.Gill arches on the outside are two rows of petals, which are supported by the supporting cartilage.In them there is a process of gas exchange.For the gill filaments suitable artery and arterial blood brings.Here it is enriched with oxygen and carries it to all the organs and tissues.On the inside are gill rakers.They serve as a filter and protects against food particles.
Like breathing fish in water?
Breath fish is as follows.When you inhale it opens wide the mouth.This gill arches apart as possible, and gill cover, on the contrary, firmly pressed to the head.Thus, the water flows into the mouth and passed on, but does not go out.Further, in the gill cavity oxygen uptake occurs through the petals.Oxygenated blood, coming to them saturated.It enriches the oxygen it carries it to all the tissues of fish.As you exhale, the mouth closes fish and gill lid is lifted.Thus, water is squeezed out.In capillaries petals on the gill arches is not only gas, but also the water-salt metabolism.The water released from blood vessels not only carbon dioxide, but also ammonia and other substances that are produced during the metabolism.This detailed description of how to breathe underwater fish.
more respiratory
But as with most species living on the Earth, the fish have additional respiratory system.Of course, the most important are the gills.But besides these, the gas exchange process involving the skin, the intestine and even special organs, such as lung sacs or "labyrinth".But all this talk is in order.Many species, especially those that are selected as a habitat muddy, oxygen-poor water, is carried out very intensively skin breath.Like breathing fish skin?It just absorbs oxygen through its surface.Sometimes it even comes out of breath in the first place.Another device - the swim bladder.It collects the air and the fish absorbs oxygen from it.So she may even survive for some time out of the water.The same role as the swim bladder, and intestines can perform.In labyrinth fish in the gill cavity has a special pocket-department.Its walls are heavily penetrated by capillaries.In them there are processes of gas exchange.It is noteworthy that the labyrinth fish breathe atmospheric oxygen.They can do without water for several days.Of course, this is not all examples of how wonderfully adapt to their environment different types of fish.They have many more secrets of how to survive even in very difficult conditions.
