Invertebrates are animals that neither own nor mature a vertebral column which is generally recognized as a backbone or spine, resulting from the notochord that supports the human body. This class of animals comprises all animals apart from the animals contained in the class of vertebrates. As per the research, nearly 97% of the animal species are invertebrates and the remaining 3% are vertebrates.
The term invertebrates are not at all times specific among the context not related to biology since it does not accurately describe the group of organisms in the same way that Arthropoda, Vertebrata, or Mandie do. Each of these terms identifies an appropriate class, phylum, subphylum, or family.
The word invertebrate originates from the Latin word vertebra, which means a joint, and sometimes particularly a joint from the spinal cord of a vertebrate. The prefix in-in-the-invertebrates means ‘not’ or ‘absent’.
MEANING OF INVERTEBRATES
An invertebrate is any animal that does not a vertebral column, or backbone, in opposition to the vertebrates that have cartilage or bones. Nearly 90 percent of the living organisms are covered under invertebrates. They include varieties of animals, such as sea stars, sea urchins, earthworms, sponges, jellyfish, lobsters, crabs, insects, spiders, snails, clams, and squid that are found worldwide. Invertebrates are specifically vital for purposes like use as pests required in agriculture, parasites, or agents for the transmission of parasitic diseases to human beings and other vertebrates.
EXAMPLES OF INVERTEBRATES
There exist various examples of vertebrates. Some of them are discussed below:
Amoeba
Amoebas are unicellular organisms that are elements of the basic group of invertebrates. Like most of the living cells in the human body, they have a cell membrane, DNA, a nucleus, and organelles. The point that differentiates the amoeba from other cellular organisms is that amoebas can go from one place to another using their characteristic feature pseudopodia, or false feet. They also catch and eat food using pseudopodia.
Earthworms
Earthworms, also called angleworms, are very vital organisms in the world because their digging turns over and enhances the soil, promotes soil drainage, and mixes in natural material. There are more than 1,800 species of worms that exist on land. Earthworms consume pieces of plants and animals present in the soil.
Starfish
Starfish are also called sea stars because of the arms or emissions that they have spiking out of their bodies. Some starfish exist deep in the bottom of the oceans, while others exist on the shore. There are over 1,600 classes of starfish. Starfish have tube bases that function with hydraulic pressure to provide them to move. Snails, mussels, and clams are common diets for starfish, which with the help of their arms direct food from the water into their mouths. These organisms have the exclusive skill to lose and regrow their arms.
CHARACTERISTICS OF INVERTEBRATES
The invertebrates have certain characteristic features which differentiate them from other organisms. Some of these characteristics are:
- Vertebral column or spine is not found in invertebrates.
- They are heterotrophic organisms which means they depend on other organisms for food and nutrition.
- They have a round, elongated, or spherical shape.
- They have an open system of respiration with spiracles, trachea, and tracheoles.
- Invertebrates reproduce sexually.
CLASSIFICATION OF INVERTEBRATES
Eighty-five in a hundred invertebrates are arthropods. Mollusks have nearly 100,000 varieties of species. Some of the most common classifications of invertebrates are:
Porifera and Cnidaria
The phylum Porifera comprises the most basic invertebrates, the sponges. Sponges do not possess real tissues. In place of tissues, sponges have specific cells that carry out activities such as digestion and reproduction. They have been found in the same form for over 600 million years. The phylum Cnidaria comprises jellyfish, hydrozoans, and corals. They are round in shape and have real tissue. Many cnidarian species are rare members of the massive coral reefs found in the regions of tropical marine.
Platyhelminthes and Nematoda
Flatworms compose the phylum platyhelminthes. They grow from three primary cell layers called germ layers and show bilateral symmetry. Both flatworms and the roundworms of the phylum Nematoda comprise several parasitic kinds, numerous of which are infectious to humans or cattle. These two phyla, therefore, have a vast influence on the health and surroundings of humans. Unlike flatworms, roundworms have a partial body structure and a complete digestive region.
Annelida and Arthropoda
Annelida consists of the common earthworm and leeches. They show a closed circulatory system, a nervous system with a basic nucleus, and a specific digestive system. Annelids commonly have a mature body structure, an excretory system, and a nervous system with a basic nucleus.
Arthropoda is a very large phylum consisting of over 80% of all kinds active on earth. They comprise insects, arachnids, and shellfish. Arthropods have segmented bodies with jointed attachments and an open circulatory system with many hearts.
Mollusca and Echinodermata
The phylum Mollusca is a very varied phylum that contains clams, octopi, and squids. One unique characteristic of mollusks is the existence of a well-built foot called a mantle that can be used for locomotion.
Echinodermata is measured as the closest related phylum to Chordata. The distinctive feature of echinoderms is its spiky exterior. They have an internal skeleton made of calcium backs that lies below a thin ectodermal sheet of tissue. Echinoderms comprise sea stars or starfish, sea urchins, and sand dollars.
IMPORTANCE OF INVERTEBRATES
Invertebrates are a vital food source for many animals:
Invertebrates exist near the lowermost of the food chain which is an important place to confirm all the other animals in addition up the chain can endure. For example, crickets are consumed by spiders, then spiders are consumed by birds, and then the birds are consumed by superior hunters such as lizards, snakes, foxes, and others. If the bottommost of the food chain does not deliver nutrients to the upper food chain, then the whole system flops.
Invertebrates confirm biological control, keeping an ecosystem in balance:
The term ‘Biological control’ means the controlling of pests without involving chemicals. Invertebrates simply consume the pests. Spiders consume insects like mosquitoes and flies. Without spiders making food from them, the number of insects would increase, creating a disparity in the ecosystem.
Invertebrates are important to the creation of products and services that help humans:
Invertebrates provide ecosystem services that confirm the making of food, medicines and confirm the essential breakdown of materials in our atmosphere. Bees, butterflies, beetles, and other invertebrate pollinators, provide several plants to reproduce and humans get access to various essential food sources. Common food items as a result of pollination include vegetables, fruits, seeds, nuts, and oils.
CONCLUSION
Invertebrates comprise all animals apart from the animals contained in the class of vertebrates. As per the research, nearly 97% of the animal species are invertebrates and the remaining 3% are vertebrates. The word invertebrate originates from the Latin word vertebra, which means a joint, and sometimes particularly a joint from the spinal cord of a vertebrate. The prefix in-in-the-invertebrates means ‘not’ or ‘absent’.Invertebrates exist near the lowermost of the food chain which is an important place to confirm all the other animals in addition up the chain can endure. If the bottommost of the food chain does not deliver nutrients to the upper food chain, then the whole system flops. The common examples of invertebrates are amoeba, starfish, and earthworms.