From the characteristics of arthropods, the reason for the wide variety and wide distribution of art

The characteristics of arthropods are:

1. The body is symmetrical.

2. It is composed of most body segments with different structures and functions, and can generally be divided into three parts: head, chest and abdomen, but some types of head and chest are healed into cephalothorax, and some types of chest and abdomen are undifferentiated.

3. The body surface is covered with a thick chitinous outer bone.

4. There is a complex nervous system and well-developed sensory organs.

5. In addition to living freely, there are also parasitic species, such as: fish fleas and fish lice that parasitize fish bodies, wood-boring water lice that harm harbor buildings and submarine power lines, and brook crabs that act as intermediate hosts for lung flukes.

As it happens, I'm also doing my homework on arthropods right now.

Hope it helps.

Because arthropods live in an extremely wide range of environments, whether it is seawater, fresh water, soil, or air. Some species also parasitize in or outside other animals. It is the phylum with the largest variety of animals in the animal kingdom, with a mixed body cavity and an open-tube circulatory system, which is highly adapted to terrestrial life and a variety of habitats, and is the most evolved group among the protostomatomy.

It is often divided into trilobite subphylum (extinct), chelicerae (forelimb chelicera), crustacea subphylum (aquatic jaws), monoclidal subphylum (terrestrial jaws), and is often divided into chelicera, crustacea, hexalimb subphylum, polylimb subphylum, and trilobite subphylum. The subphylum unilimb has been discarded due to inaccurate evidence.

The phylum Arthropod is the largest phylum in the animal kingdom and is commonly known as arthropods. There are about 1.2 million extant species in the world, accounting for 80% of the total number of living species.

Arthropods are the most diverse and widely distributed group in the animal kingdom for the following reasons.

First, it has appeared for a long time and has evolved for a long time. Arthropods appeared about 81 billion years ago, and today, 800 million years is enough time for them to evolve many species.

Second, it adapts to a wide range of environments. Whether it is seawater, fresh water, soil, or air, they can adapt to a variety of environments from cold to heat, from desert to rainforest, from underwater to sky. Some species also parasitize in or outside other animals.

Third, the individual is small and easy to survive. Due to the limited load-bearing capacity of the exoskeleton, most of the arthropods are small, and there are not many more than 10 cm in length. If the individual is small, he needs less energy, has a wide range of food, and is easy to use various environments to avoid danger and injury.

Fourth, there are many reproductive methods. Most arthropods are dioecious and have in vitro fertilization, and many are in vitro fertilization. There are oviparous and ovoviviparous.

Eggs have direct and indirect development. There are also arthropods that are capable of parthenogenesis, i.e., reproduction without fertilizing eggs. And the amount of eggs laid at one time is large, and the number grows rapidly.

Fifth, the generation time is short. Most arthropods develop quickly, developing from eggs to adults and reproducing within a few months. Some species even take only a dozen days to fully develop. This enables arthropods to evolve rapidly and expand their populations rapidly.

The variety and number of arthropods are mainly related to the following characteristics:

1. There is an exoskeleton on the body surface, which can prevent the evaporation and loss of water in the body, and can also resist some external attacks and injuries;

2. The locomotor organs are well developed, and there are many leg joints, which is easy to move; Most of them can fly, making it easy to escape and find food;

3. Different types of mouthparts are different, with a variety of styles, increasing the range of food;

4. The head has antennae, which is easy to perceive air flow and the surrounding environment, and has a single eye and compound eyes to increase the visual range;

5. Strong reproductive ability, large number of offspring, short growth and development cycle.

(1) A well-developed and thick exoskeleton;

b) Efficient respiratory organs Trachea (mainly found in insects and myriapoda) (iii) well-developed nervous system;

d) the division of the different rhythms and the divisions of the body;

v) segmented appendages;

6) Sensitive sensory organs;

vii) Bones with chitin and protein in vitro.

The main characteristic of arthropods is that the body is composed of many body segments and is segmented; There is an exoskeleton on the body surface; The feet and antennae are also segmented; In addition, there are a pair of antennae and a mouthpart on the head of arthropods, some have monocular and compound eyes, and some only have compound eyes, so arthropods are very adaptable to the environment

Therefore, the answer is: the body is composed of many body segments, and they are divided; There is an exoskeleton on the body surface; Foot and antennae segmented

There is a tough exoskeleton on the body surface; Both the body and appendages are segmented.

1. The main characteristics of the phylum Arthropod.

1. Heterorhythmic segmentation and appendages;

2. Exoskeleton and muscles;

3. Mixed cavity and open circulation system;

4. Diverse respiratory and excretory organs;

5. Digestion and feeding;

6. Nervous system and senses;

7. Reproduction and development.

There are several reasons for this.

One is that arthropods live for a long time. Among multicellular animals, arthropods have lived for more than 500 million years. Arthropods appeared in the Early Cambrian period, more than 500 million years ago. Long-term evolution has made arthropods very diverse and very widely distributed.

The second is that arthropods have a very strong reproductive ability. Arthropods grow rapidly, have a short generation time, and lay a large number of eggs at a time, so the population is extremely large.

Third, arthropods are adaptable. When arthropods appeared, they were exclusively aquatic animals. But as early as the Ordovician period, more than 400 million years ago, arthropods landed with the landing of plants, and were the first animals to land on land.

After arriving on land, arthropods quickly evolved, successfully adapted to life on land, and with their strong adaptability and fecundity, they spread rapidly on land.

Fourth, it is small in size, which is easy to avoid danger. Arthropods are exoskeleton animals, and the bone components are chitin, which are polysaccharides, and cannot bear excessive weight, so arthropods are small in size. But it's also an advantage.

In the mass extinction events from the end of the Permian period 100 million years ago to the mass extinction 65 million years ago, arthropods have successfully survived, and with their strong reproductive ability and adaptability, they have quickly adapted to the changing environment, expanded the population, and become the most successful animal type so far.

The number of reproductions is large, the genetic variation is short, and the peculiar genes can carry accurate and complex behavioral instructions.

Most of the evolution of arthropods does not conform to Darwin's theory of evolution, and most species do not have a gradual evolutionary adaptation process, and new species are formed quickly. Arthropods, especially insects, have genes that carry accurate and complex behavioral instructions, much like computer instructions, and through combination and group execution, they can form the adaptability of higher organisms, and in many cases even seem to surpass the more capable vertebrates, which makes them extremely adaptive.