Arthropoda

What are arthropods?

Arthropods are an invertebrate with an exoskeleton, a body with somite, and paired appendages. Arthropods form the phylum Arthropoda. They are often characterized by articulated limbs and cuticles made of chitin mineralized with calcium carbonate. The arthropod body plan consists of segments with a pair of appendages. Arthropods are symmetrical and their bodies have an external skeleton. To continue to grow, it must go through the moulting stage. This is the process of stripping off the exoskeleton and revealing a new exoskeleton. Some species have wings. They are a very diverse group of up to 10 million species.

The lumen of an arthropod, the hemocoel, houses its internal organs, through which blood lymph, an analogue of blood, circulates. It has an open circulation system. Like their exterior, the internal organs of arthropods are generally composed of repeating segments. Their nervous system is “ladder-like,” with paired ventral cords passing through all segments, forming paired ganglia in each segment. Their heads are formed by the fusion of various numbers of segments, and their brains are formed by the fusion of the ganglia of these segments and surround the oesophagus. The respiratory and excretory systems of arthropods depend on both the environment and the subphylum to which they belong.

Arthropods use a combination of compound eyes and pigmented spots visually. In most species, the self can only detect the direction of light and the compound eye is the primary source of information, but the main source of the spider’s eyes is the self, which produces images and, in some cases, rotates and prey. It can be tracked. Arthropods also have a wide range of chemical and mechanical sensors, primarily based on modifying many bristles known as bristles protruding from the cuticle. 

Similarly, their breeding and development are diverse. All terrestrial species use internal fertilization, which may be done by indirect movement of sperm through the appendix or ground rather than by direct injection. Aquatic species use internal or external fertilization. Almost all arthropods lay eggs, but many species give birth to live young after the eggs hatch in the mother, and some are actual embryos like aphids. Arthropod larvae range from small adults to limbless larvae and caterpillars that metamorphose ultimately into adults. The care range for mothers of young animals varies from non-existent care by social insects to long-term care.

What are the characteristics of arthropods?

The characteristics of arthropods are:

• A segmented body with head, chest and abdominal segments. Comes with at least one segment. They can be used for feeding, sensory ingestion, defence and movement.
•  In addition to the legs, the antennae and mouth are considered modified appendages. Nervous system. 
• A tough chitinous exoskeleton that gives them physical protection and resistance to dehydration. To grow, arthropods uncover this outer cover in a process called moulting. An open circulatory system contains blood lymph, which is fluid like blood.
•  A series of hearts move blood lymph into the body cavities, where they directly contact tissue. Blood lymph is involved in the distribution of oxygen. 
• The complete digestive system with mouth and anus.  
• Aquatic arthropods use gills to exchange gas. These gills have a large contact area with water and can take in more oxygen.
• Terrestrial arthropods have an inner surface that aids in gas exchange. Insects and most other terrestrial species have a tracheal system, through which the air sac leads to the body through the pores of the exoskeleton. 
• These pores cover most of the outer surface of the body. Others use book lungs, gills modified to breathe air, as seen in species like coconut crabs.
•  Some parts of the crab’s legs are covered with skin that absorbs oxygen. Crabs can have two different structures. One is for breathing in water and the other is for taking oxygen from the air.

Examples of arthropods

• Chelicerata: horseshoe crabs, spiders, scorpions, spider crabs, mites 
•  Crustaceans: Artemia, barnacles, red shrimp, crabs, shrimp, remipedia 
•  Three orders for hexapod insects and entognatha: Collembola, Protura, Diplura 
•  Myriapoda: Centipede, Millipede, Pauropoda, Centipede (known as the glasshouse Symphyla or garden centipede)

Conclusion: 

Arthropods include four living subphyla. Chelicerata such as spiders, mites and scorpions. Centipedes and Myriapoda include centipedes; hexapods include insects; and crustaceans. Arthropods are characterized by a segmented body, a rigid exoskeleton, and appendages used for nutrition, sensory structure, defence, and movement. Many arthropods play a vital role in the ecosystem. Arthropods are ecologically important due to their large number and incredible diversity. Bees, ants, butterflies, moths, flies and beetles are invaluable pollen matters.