Sunday, August 30, 2020

Animal Kingdom: Invertebrates Chapter 1 ( Basics of Zoology)


Invertebrates 1 ( Basics of Zoology)

The term invertebrates is not a scientific classification, it simply describes all animals that lack internal attached skeletons. The animal kingdom has more than 30 independent invertebrate phylums.

We are going to observe the wildlife or the animal kingdom.We are going to view 10 of them.

The term refers to a variety of animals, from microbes to giant squid, which is not uncommon except for the absence of vertebrate skeletons.

Some are soft-bodied, and most have protective shells, but the most abundant are crustaceans, insects, spiders, and similar animals that have rigid, attached external skeletons - arthropods.

Most of the animals on earth are not curly mammals, scaly reptiles or birds without birds. They are invertebrates - animals that do not have attached skeletons.

Many live in the oceans, but most live on land, and most of all, insects.


Not all animals have the most common organs and have similar cells.These aquatic creatures are the simplest animals. It contains many cells, but they do not have specific organs. They collect food by filtering it out of the water. We know this particular type of animal species as a sponge.


Jellyfish, corals, marine anemones and their relatives are all man-eating aquatic animals that are usually armed with stinging cells to catch prey.

Many are beautiful, but some can be deadly. The body of a typical synergist is made up of body jelly and is bound by two layers of those cells - one on the outside and the other lining the animal's stomach.

It can also have a crown of mobile tentacles . Some cnidarians are free-briefing medusi or jellyfish, but many have polyps (hollow cylinders surrounded by tents) that attach their life to rocks or near the ocean.Many corals and sea anemones form colonies of interconnected polyps that share nutrients that accumulate in the water.

Location: North Pacific Ocean
Size: Up to 30 in (76 cm) across

Passing through the North Pacific Ocean, these colorful jellyfish caught small, long-tailed tiny animals in traps and then wrapped them in body caverns for digestion.

(Do you know, 
The jellyfish has only one opening in its body, hidden within the bell. It takes in food and expels waste through this same hole.)

It can swim slowly by contracting its bell-shaped body, but for the most part it flows with the currents of the ocean. Simple animals include jellyfish.They have senses, no brain to process and store information, and only the most basic digestive system.

But they have a complex lifecycle and their long, rear tents armed with terribly impressive toxic stinging cells make them highly efficient predators.

The venom of the Sea nettle can be deadly, but it does not bother some small fish, such as the Pacific butterfish. A thick layer of fine mucus stops the penetrating cells in their skin. The tents at the back of the jellyfish have a shelter for the fish from their enemies.


Mainly marine, these include the snails, clams, and octopuses and their relatives

Some of the most invertebrates in these predominantly marine animals are the most colorful and diverse.

Most have wide shells that protect their soft bodies, some can survive in contact with the sea shore.

There are three main groups in Molsk.

Cephalopods (see pp.24-25) include octopuses and their relatives. Gastropod snails and slugs are

primarily mobile animals crawling on muscular legs; Many people hunt and hunt. Beavers with two

shelves often live in towers or attached to rocks and filter food for water.


Most mollusks resemble clams or snails. But a few are very different, with long, sucker-covered arms and tentacles, highly developed eyes and brains, and a remarkable learning ability.

These are the octopuses and their relatives the cephalopods. The word cephalopod means “head-foot” and describes how the limbs of an octopus, squid, or cuttlefish seem to be attached directly to its head.

The limbs surround a beaked mouth, often armed with a paralyzing venom. Water drawn into the body for vital oxygen can be ejected via the siphon to propel the animal out of danger, often along with clouds of enemy-confusing ink.


Location: North Pacific

Length: Up to 10 ft (3 m)

Diet : Crustaceans, mollusks, and fish

The biggest octopus is a cunning hunter that preys on any animals that stray near its rocky seabed lair. It can slip its elastic body through the smallest gaps, then shoot off through the water like a missile.The octopus has eight highly flexible arms.

(Do you know, 
Near the base of the siphon tube is the opening to the ink sac. The octopus can shoot out an inky cloud to disorientate predators.)

Each of the octopus’s long, muscular arms is equipped with more than 250 suckers to give it a secure grip on prey. The suckers are extremely strong, enabling the octopus to rip crabs and clams apart to get at their soft flesh

The octopus has a tough, horny beak shaped like a parrot’s bill, which it can use to crack the shells of crabs and similar prey. It injects them with a dose of digestive venom to soften the flesh, scooping it out with its rasping tongue and discarding the empty shell.

Phylum : Echinoderms

Starfish, sea urchins, and their relatives are known as echinoderms, which means “spiny-skinned.” The spines are very obvious on some sea urchins, which are the prickliest creatures on the planet.

Other echinoderms are studded with hard plates, or have flexible but tough skins. All sea-dwelling creatures, they have bodies that are built on a radial plan, with a mouth and stomach in the center and segments extending outward like a flower.

Common starfish


Location: North Atlantic

Size: Up to 193⁄4 in (50 cm) across

Diet : Immobile animals and carrion

Gliding over the seabed toward a clam, on hundreds of flexible feet, the common starfish creeps up on its victim and launches an attack. It pulls the clam’s shell apart so it can consume the soft flesh within.

A starfish may not look like a hunter, but to other marine animals it is a voracious predator, prepared to eat anything even other starfish that cannot escape its clutches. It hunts by scent, following the chemical trail until its victim is within reach.

(Do you know,When spawning, a female common starfish releases up to 2.5 million eggs.)

Gripping the prey animal with the suckers of its tiny tube feet, the starfish forces out part of its stomach lining through its central mouth and smothers the soft parts of its victim with digestive juices. The juices break down the prey’s soft tissues, so the starfish can suck them into its body.

Other Phylum in Next Artical

Previous Post
Next Post

Myself Kartik Raising and I completed my bachelor in zoology from KBC NMU, Jalgaon Maharashtra India 425209