If you are a fish lover, the best thing is to take a pencil and paper because some of the qualities of these animals will leave you with your mouth open.
Fish are considered vertebrates of aquatic life and breathe through gills; they live in both fresh and saltwater, and it is estimated that there are currently more than 20,000 species.
Animated Cute Fish Pictures
Fish have always played an essential role in their relationship with men, as they are a significant source of food, which is why the fishing industry has specialized in the capture and reproduction of these animals to facilitate their human consumption.
Fish, in general, is a food rich in proteins of high biological value, which contain all the essential amino acids, it is also rich in fats that contain a high proportion of unsaturated fatty acids, as well as vitamins and minerals.
This composition is so suitable for human nutrition. It is also for the microorganisms that are typically located at the level of the gills, mucus covers the skin and abdominal contents, and that, during its growth after the death of the animal, would be decomposed progressively, if the process was not stopped.
In this process of decomposition, the animal’s enzymes also intervene, which, in the same way as the microorganisms, degrade the proteins, fats, etc.
For all these reasons, it is said that fish is a very perishable food, that is to say, that it alters quickly, which requires that it be kept in the proper conditions of conservation until it is consumed and that it is acquired as fresh as possible.
They base their structure on a cartilaginous skeleton with a skin covered with hard scales. Stripes or sharks are the most prominent of organisms that lack a swim bladder.
A bony skeleton governs Their body, and their differential feature is based on having a swim bladder. It should be noted that there have been cases in which the bladder has evolved into a kind of lung.
There is the practice of angling; it brings together a vast number of enthusiasts and is considered worldwide as a sport. Many people want to keep aquatic vertebrates as pets, either to house them in a simple fish tank or with more sophisticated means such as the aquarium, equipped with mechanisms that make them adapt favorably to life in captivity.
Aquatics, nowadays, apart from being a very entertaining hobby, can be considered as a relaxation method that releases the accumulated stress in our daily life. As an example, we mention some typical species in freshwater and saltwater aquariums.
In the past, the term “fish” was used to group aquatic forms that were characterized by having a pisciform body. Today, the class “Pisces” has become obsolete, although it is still maintained by tradition, although it is no longer given the status of a taxonomic category.
Reproduction is variable depending on the type of fish. There are three classes: viviparous, oviparous and ovoviviparous. Ovoviviparous retain the eggs inside the mother and are expelled at the moment of hatching. It is a way to protect their offspring from predators. The embryo feeds on the yolk existing in the egg.
Viviparous has an extraordinary way of feeding the embryo. Either by ovarian secretions or by placentation. The oviparous species expel the eggs into the natural environment, and their fertilization is external, unlike the previous ones.
Fish are defined as the first vertebrate animals to emerge on Earth. An origin that dates back 400 million years, and that is framed as one of the ancestral creatures of our planet.
Fish are defined as a unique feature of this animal kingdom. The swim bladder is a membranous, air-filled sac located in the digestive tract. This vital organ allows fish to float much more quickly. In other words, it is what provides fish to rise naturally to the surface.
The environment they chose was water, and that is why they developed a complex respiratory system that enabled them to take in oxygen without coming to the surface: the gills.
Although all fish have a mouth, we need to know that not all species have developed jaws. Those that do have developed jaws have access to a wide variety of foods, including plants and other living organisms.
Once the food is ingested through the mouth, it passes directly into the stomach. Nutrients are absorbed through the intestine while the liver and pancreas add digestive enzymes.