Why is the frog considered an amphibian, is the frog an amphibian, and what are his close relatives?

The frog is an amphibian, and his close relative is the toad.

Frogs belong to the amphibians of the phylum Chordates, amphibians, tailless, frogs, adults without tails, eggs laid in water, fertilization in vitro, hatching into tadpoles, respiration with gills, after mutation, adults mainly use lungs to breathe, and also use ** breathing. The upper jaw has teeth, usually vomer teeth. shoulder girdle fixed thoracic type, vertebral body uneven type, recommended vertebral transverse process columnar; There is no intermediated cartilage between the two bone nodes at the end of the toes.

The tympanic membrane is distinctly hidden under the skin,** smooth or with wart grains. The tongue is generally oblong, and the posterior end is mostly notched.

The frog body can be divided into 3 parts: head, trunk, and limbs. Frogs have four toes on their front feet and five toes on their hind feet, as well as webbed. On either side of the frog's head are two small bags that bulge slightly.

That's its eardrum, through which the frog can hear sounds. The frog's back is green, smooth, soft, and patterned, and its belly is white. You can hide it in the grass, make it easier to catch pests, and you can also protect yourself.

It's also helps it breathe. Its air sacs are only found by male frogs. Frogs prey on their tongues, which have mucus on their tongues.

Frogs are amphibians and vertebrates, frogs lay eggs in the water when they are young, and then they become tadpoles after hatching, small tadpoles cannot live on land, they need to grow in water all the time, and at this time they have to use their gills to breathe. After that, it slowly grows into a frog form and breathes with its lungs.

The habits of frogs.

1. Temperature frogs are ectothermic animals, and their body temperature changes with the change of external temperature. Under natural conditions, the suitable temperature for frog growth is 20-30, and the optimal temperature is 25-28. When the winter temperature drops below 10, feeding and activity gradually decrease. When it drops below 5, it burrows into a cave or hibernation in the silt at the bottom of the pool.

The following year, hibernation ends in early spring when the temperature rises. When the water temperature exceeds 32 or above, the activity decreases significantly. Temperatures above 35 will cause frogs to die one after another.

2. Humidity and humidity are an important factor in the survival and growth of frogs, because the tissue structure of frogs does not protect the evaporation of water in the body, and it is obviously not enough to rely on the mucus secreted by the gland to eat the humidity on the body surface. Therefore, the frog's habitat should be both a pond with water and a warm and humid environment with weeds.

There is a close relationship between humidity and temperature, the higher the temperature, the higher the humidity, otherwise the high temperature and dry environment, and the rapid evaporation of water is not conducive to the growth and survival of frogs.

3. Light frogs are nocturnal and afraid of direct sunlight, but they tend to be weak in light, and usually like to inhabit in sunny and shaded grass. Light has a promoting effect on the metabolism, growth and reproduction of frog body, such as living in the dark for a long time, its gonads are difficult to develop and mature, and even stop laying eggs and ejaculation.