Legless Amphibians: Representatives (photo)

The diversity of the fauna of our planet is very great. There are among its representatives and such interesting species of amphibians as the legless amphibians. Otherwise they are called "worms".

Detachment: The legless Amphibians: features of the structure

Outwardly they resemble large worms. This similarity is due to the presence of numerous ring-shaped interceptions of the body. A small head connects with a long body, which has neither tail nor limbs. The cloaca is located on the posterior pole of the body.

The dimensions usually do not exceed 45 cm. But there is one exception. This is the worm of Thompson, which lives in the Colombian mountains. The body can reach 1.2 meters in length.

Under the skin of the worms there are special scales that were a sign of the long armored ancestors of legless amphibians.

There are characteristic features of fish in these organisms: the presence of a large number (200-300) of vertebrae on the remains of the chord. The heart consists of one atrium, separated by an incomplete septum, and one ventricle. The features of the forebrain structure indicate a higher stage of development of worms compared to other amphibians.

Adaptation to the environment

The legless amphibians live underground. The consequence of this is the absence of eye organs. Their rudiments hide under the skin or grow into the bone. The hearing is also poorly developed. The auditory orifice and the tympanic membrane are absent, the inner ear is present, but it has no connection with the environment. Therefore, legless amphibians can catch only loud sounds with a frequency of 100-1500 hertz. The poor development of the above sensory organs is compensated by an excellent sense of smell.

Color rather modest. Skin color varies from gray and brown to black. Homelessness helps the worms in disguise. There are exceptions. In nature, you can find specimens of bright yellow and blue.

Nutrition and movement

Feed on blindfolders, earthworms, shield-tailed snakes, soil insects and mollusks. Some annular worms use termites and ants as their main food.

The legless amphibians have perfectly adapted to their way of life. A small solid head makes it easy to lay a path under the ground. The movement is also helped by a long body and a large amount of mucus. Its release occurs due to numerous cutaneous glands, concentrated in the rings of the anterior section. This feature saves worms from attacking snakes, termites and ants.

Spread

Tropical zones with a humid climate are an ideal place for the habitation of worms. They are distributed on the islands of the Pacific and Indian oceans; In the river systems of Colombia, Amazon and Orinoco. In Africa, America, Asia, these amphibians are common everywhere. They do not live in Australia and in Madagascar.

Reproduction

Detailed studies on this issue have not been conducted. But one thing is certain: reproduction is internal. Cloaca of male individuals can turn outward, forming a copulatory organ, through which the actual pairing is possible. This sign characterizes all the animals of the order. The legless amphibians. Representatives who live in the aquatic environment have acquired several adaptations for this. In particular, their cloaca has sucking disks. With their help, the pairing of matings takes place. Duration of mating is 3 hours. Unlike most other amphibians laying eggs in damp earth, worms do not need a river or lake for this.

They use their own mucus instead of water. Order The legless amphibians are also characterized by live birth. The duration of pregnancy is 6 months or more, the birth is born from 3 to 7 cubs. The body length of newborns is not more than 10 cm, and in the rest they are absolute copies of adult individuals of the detachment. The legless amphibians. The photo of the young is presented below.

From the first days they feed themselves on the branchial sacks, which the female extracts for them.

Squad Legless Amphibians: Representatives

The Central American worm lives in Guatemala. The female of this species is capable of bearing from 15 to 35 eggs. Childbirth occurs in May-June, when the rainy season starts. The length of the born calves is 11 to 16 mm. Despite the tiny sizes, they are very mobile and viable. Rapid growth allows them to reproduce at the age of two.

A female squeezed-tailed worm is formed from 6 to 14 eggs. When the larvae lack the yolk present in the eggs, they are selected from the egg shells, but are not yet born. Their place of residence for some time is the mother's oviduct. Small worms already have leaf-shaped teeth at that time. With their help, they scrape the walls of their temporary shelter, which leads to the release of nutritious mucus. It they eat.

They also receive oxygen from their mother. With the help of larvae of large gelatinous gills, they "suck" to the walls of the oviduct, and oxygen is thus delivered to them.

For the earthworm of fish breeding, inhabiting India, Sri Lanka and the Great Sunda Islands, egg laying is characteristic.

They are large, in one masonry there are from 10 to 25 pieces. Due to the dense shell covering them, and special outgrowths by which the eggs are attached to each other, the lump of the calf represents a compact mass of itself. The female folds in a ring and incubates eggs, abundantly lubricating them with mucus. Due to this they increase in size by almost 4 times. Hatching, these legless amphibians, whose adult generation is a land-based species, live for some time in the water until they finally mature.