Fish and the frog: similarities and differences

Even in the lessons of biology teachers talk about various representatives of the fauna. Among them - the first chordates and vertebrates of our planet. These include fish and amphibians. About the similarities and differences between fish and frog, read in the article.

Fish

Since ancient times these vertebrate animals have inhabited all kinds of water bodies. Evolution made them change, as a result of which the first amphibians emerged on land. Fish live almost everywhere. They are the largest superclass of primary chordates. In total, science knows more than twenty thousand species of these animals.

Fishes are cold-blooded representatives of fauna. They strongly depend on the temperature of the environment, the rate of their life processes varies depending on the temperature conditions. In the winter season, when the water cools down to zero degrees and below, the fish simply descend to the bottom of the reservoir, because there is always a plus temperature.

Fish and frog are the most important components of many food chains. They not only eat other plant and animal organisms, but they themselves become food for predators. Many fish are prey to humans. Because a huge number of these animals die as a result of fishing, some species of fish were listed in the Red Book or disappeared from the face of the Earth.

Frogs

Amphibians are the first animals to set foot on land. They can live on land and in water. While fish live in salty and fresh water bodies, amphibians can be found only by rivers.

Fish and frog have a number of similarities and differences. Amphibians have pronounced limbs that allow amphibians to jump high. Their skin is naked, covered with mucus. They have a well developed vision - it helps them to notice prey from afar and then catch it with a long sticky tongue. Frogs are cold-blooded animals, so the peak of their activity is in the warm season. Most often they can be found in wetlands, wet forests and various water bodies.

Similarities

Describing the similarity of fish and frogs, we can not say that they are similar not only externally, but also internally. This is manifested in the fact that newly hatched tadpoles resemble the shape of small fish. In the adult state, their similarity is due to the fact that the heads of these representatives of the fauna smoothly pass into the trunk. The frog has a single cervical vertebra, while in the fish the neck is replaced by the posterior gill cover.

In addition, both the fish and the frog have a mouth slit and large eyes. This is one of the most obvious similarities in their external structure. As for the nasal sinuses and nostrils, the amphibians and fish have two pairs. True, two of the four nostrils of the frog are in her mouth, while all the nostrils of the fish are located on her head.

The fish and the frog have well developed musculature. If in amphibians this is associated with motor activity, then in fish - with swimming. The fact is that it is important for them to stay in the water and resist its current. They have separate muscles that are responsible for the movements of the eyes, fins and other parts of their body.

Both those and other representatives of the fauna lay eggs. In this case, fry of fish and tadpoles are chordates. Both representatives of the fauna are cold-blooded, which makes them dependent on the temperature around.

Differences

As stated earlier, fish and frog have both similarities and differences. They are both external and internal.

First of all, they lie in the structure of the skeleton. The frog has a cervical vertebra, while it lacks the fish, and there are fewer bones in the amphibian skull. The head of the frog is connected to the body movably. Its spinal cord is protected by several arcs. While fish have gills, amphibians do not have any gill bones, nor their lids.

The muscular skeleton is also different in these fauna. Due to the fact that the frog not only floats in the water, but also moves overland, the muscles of its limbs are well developed. In addition, she can lower and raise her head. Amphibians can move in different directions, while fish movements are monotonous and somewhat similar to snake. The difference between a frog and a fish is also hidden in the structure of their eyes. The fact is that in fish they are flat, and in amphibians - convex.

The body shape of these representatives of the fauna is very unlike. First, the shape of the body of the fish is streamlined, which contributes to its high speed of movement in the water. The skin of aquatic inhabitants, as a rule, is covered with scales, and the skin of amphibians is bare. This is one of the many differences between amphibians and fish.