Since getting educated at school, everyone knows that fish are cold-blooded animals. And not everyone knows that some representatives of the water inhabitants are not cold-blooded. The article will introduce you to these exceptional animals and the benefits of their existence, and a photo of warm-blooded fish will visually complement the information provided.
Cold-bloodedness as a way of life
To understand all the features of warm-blooded fish, it is necessary to highlight the main points associated with cold-bloodedness of most representatives of this class. This term means that in such animals the body temperature is not constant and varies depending on this indicator in the environment and space. This is expressed in the fact that in an environment with a high temperature the activity of such animals is higher, and the speed of movement, too. The reason for this is increased energy production, which allows muscles to work more intensively.
In cold weather, fish are calm and slow, their metabolism slows down. This is a danger to them, because if the temperature remains low for a long time, it can lead to the death of the animal. To avoid this, the fish descend into warmer and deeper waters, and certain species have a special protein with antifreeze properties in the blood.
Warm-blooded fish
This concept is associated with the ability of a living organism to maintain a constant body temperature, regardless of the ambient temperature. And yet there is a difference between fish and, for example, a bird that has this same feature. The latter have an excellent structure of the circulatory system and maintain a regular temperature mainly due to the independent generation of energy from the food that they consume. Warm-blooded fish use another mechanism to increase the degree of body heating, based on muscle contraction and small subtleties in the process of regulating blood flow.
Scientists from America discovered the first exceptional instance on May 15, 2015. At the moment, the list of warm-blooded fish is small, only three representatives. But research does not end, so new names can be expected. In the meantime, consider the features of the three existing ones.
Moonfish, or ruddy feather
These are magnificent, large and deep-sea fish that can descend almost 500 meters into the oceans. They feed on squid and small fish. The body of the fan is very large in height and strongly flattened from the sides. The length of this fish varies from one and a half to two meters, and its approximate weight is about 50-60 kg. Very dynamic fluctuations of the pectoral fins help maintain the body temperature of the odor higher than the temperature in the water. And fish can keep warm thanks to a large layer of adipose tissue and a peculiar structure of blood vessels in the gills. This allows the fan to be perfectly oriented, as well as to react with lightning speed to what is happening around. It is this fish as a warm-blooded animal that is considered full-fledged, unlike the others listed below.
Skipjack or Striped Tuna
Striped tuna is a large fish with a thick and rounded body up to 100 cm long (in rare cases, exceeds one meter). Its diet is made up of small fish, crustaceans and squids. Intensively contracting muscles help heat the body, and the cooling process is controlled by the peculiar structure of the blood supply system. Warm-bloodedness allows massive tuna to travel at high speed, which makes them quite dangerous hunters. Tuna fish is very much appreciated in the world of cooking due to its dense structure resembling meat and useful properties.
Some types of sharks
Consider the following types:
- Mako Shark. The weight of these creatures can reach up to 400 kg. The body is about 3-4 meters in length, elongated, which makes it possible to move very quickly in water. The color of this species justifies its second name, such as "gray-blue shark": dark blue on top and almost white on the abdomen. With such a shade, this predator is completely invisible at depth, and it helps a lot to hunt for food.
- Blue shark. In this species, the appearance typical of a family member has outstanding pectoral fins that exceed the standard length. The approximate weight of this predator is approximately 130-180 kg. Very elongated, oblong and pointed muzzle. The highest speed that this predatory fish is capable of developing is 40 km / h.
- Great white shark. This is one of the largest predators on the planet. This fish got its fame as a cannibal shark for a reason: very many cases of attacks on people have been recorded. It exceeds even killer whales in size, and can reach a length of 12 meters. This predator has the largest teeth of all existing fish (5 cm). White sharks feed mainly on crabs, fish, shellfish and small marine animals.
The body of all these warm-blooded fish warms up due to increased muscle contraction, and body temperature is about 7-10 degrees higher than the temperature of the water. When there is a transition to cooler waters, it is these sharks that can control the blood supply to internal organs. Blocking the access of blood to the least important parts of the body helps to rationally spend precious heat.