Animal Classification

Cnidaria

Explanation- Cnidaria is diploblastic i.e. it consists of two germ layers. There is an absence of body cavity in it which makes it an acoelomate.

Star fish

Explanation- Starfish belong to the phylum Echinodermata. Their body is triploblastic, acoelomate and are radially symmetrical in the adult stage.

Ascaris (Intestinal worms)-Phylum Aschelminthes

Explanation- The intestinal worms belong to the Phylum Aschelminthes. Body of these animals is triploblastic and

Pseudocoelomate.

Porifera

Explanation- Animals belonging to the phylum Porifera have the simplest body plan and are called as sponges. They bear numerous pores on their body.

1. Bath sponge: Phylum- Porifera

These animals are with simplest body plan and are called as ‘Sponges’. They bear numerous pores on their body. Those pores are called as ‘Ostia’ and ‘Oscula’. These are aquatic animals and are mostly asymmetrical.

2. Grasshopper: Phylum- Arthropoda

These animals have jointed appendages. Body of these animals is triploblastic, eucoelomate, bilaterally symmetrical and segmented.

3. Rohu: Phylum – Pisces

These are cold blooded aquatic animals living in marine and fresh waters. Their body is spindle shaped to minimize water-resistance. They have paired & un-paired fins for swimming. The tail fin is useful as a steering organ during swimming. They use gills for respiration.

4. Penguin: Phylum- Aves

These vertebrates are completely adapted for aerial life. These are warm blooded i.e. they can maintain their body temperature constant and their body is spindle-shaped to minimize air resistance during flight. Their forelimbs are modified into wings and the digits are covered with scales and bear claws. Exoskeleton is present in the form of feathers.

5. Frog: Phylum- Amphibia

These animals are strictly aquatic during larval life and perform only aquatic respiration whereas they can live in water as well as on land during adult life and can perform aquatic as well as aerial respiration. They have two pairs of appendages and their digits are without claws.

6. Lizard: Phylum- Reptilia

These are cold blooded animals. They creep on the land as their body cannot be lifted up. Their skin is dry and scaly.

7. Elephant: Phylum- Mammalia

Presence of mammary glands is typical character of this phylum. These animals are warm blooded. Their body is divided into head, neck, trunk and tail and their digits are provided with nails, claws, or hooves.

8. Jellyfish: Phylum- Cnidaria

Body of these animals is cylindrical or umbrella-like. Most of these animals are marine. Only few are fresh-water dwellers. Their body is radially symmetrical & diploblastic. Tentacles are useful for capturing the prey whereas cnidoblasts inject the toxin in the body of prey. Those are useful for protection too.

i. Greek philosopher Aristotle was the first to perform the animal classification. He classified the animals according to the criteria like body size, habits and habitats. It is known as ‘Artificial method’.

ii. Besides Aristotle, artificial method of classification was followed by Theophrastus, Pliny, John Ray, Linnaeus, etc.

iii. Later on, ‘Natural system of classification’ was followed. Natural system of classification was based on various criteria like body organization, types of cells, chromosomes, bio-chemical properties, etc. Dobzhansky and Meyer propagated the use of system of classification based on evolution.

iv. Recently, Carl Woese has also proposed the animal classification. This system of animal classification was in practice till now.

v. At present, according to the five kingdom classification system of Robert Whittaker, all multicellular animals are included in Kingdom: Animalia. This system of classification is based upon some criteria like Body organization, Body symmetry, Body cavity, Germinal layers, Segmentation, etc.

a. Body Organization

i. Body organization of unicellular animals is referred as ‘Protoplasmic grade’ organization.

ii. In case of multicellular animals, if tissues are not formed, their body organization is called as ‘Cellular grade organization’. Ex. Phylum-Porifera.

iii. In case of some animals, cells come together to form tissues with the help of which all the body functions are performed. Such animals show ‘Cell - tissue grade’ organization. Ex. Animals from phylum- Cnidaria.

iv. Flat worms show ‘Tissue-Organ grade’ organization. In this type of organization, tissues are organized to form some organs. However, complete organsystems are not formed.

v. Remaining all animals show ‘Organ-system grade organization’ in which different organs are joined together to form organsystem that performs specific functions. Ex. Crab, Frog, Human, etc.

b. Body symmetry

vi. In imaginary sense, if body of any animal is cut through imaginary axis of body, it may or may not produce two equal halves. Depending upon this property, there are different types of animal bodies.

vii. Asymmetrical Body: In case of such body, there is no any such imaginary axis of the body through which we can get two equal halves. Ex. Amoeba, Paramoecium, some sponges.

viii. Radial symmetry: In this type of body, if imaginary cut passes through central axis but any plane of body, it gives two equal halves. Ex. Star fish.

ix. Bilateral symmetry: In this type of body, there is only one such imaginary axis of body through which we can get two equal halves. Ex. Insects, fishes, frog, birds, human, etc.

Kingdom- Animalia

Sub-kingdom- Chordates

Phylum- Chordata

Subphylum- Vertebrata

Class- Pisces

1. Calcareous spines are present on the body of these animals; hence they are called as echinoderms.

2. These animals are found only in ocean.

3. Their body is triploblastic, eucoelomate and it is radially symmetrical in adult stage. However, they show bilateral symmetry in larval stage.

4. They perform locomotion with the help of tube-feet. Tube feet are also useful for capturing the prey. Some animals are sedentary. Examples: Star fish, sea-urchin, brittle star, sea-cucumber, etc.

1. Cockroach belongs to the phylum Arthropoda.

2. These animals have jointed appendages.

3. They are found in all types of habitats ranging from deepest oceans to highest mountains.

4. Body of these animals is triploblastic, eucoelomate, bilaterally symmetrical and segmented.

5. Chitinous exoskeleton is present around their body.

6. These animals are unisexual.

Amphibians are strictly aquatic during larval life and perform only aquatic respiration whereas they can live in water as well as on land during adult life and can perform aquatic as well as aerial respiration. This characteristic is not seen in tortoises that are cold-blooded animals and are observed to creep on land. Hence, they are included in the class Reptilia and not Mammalia.

Jellyfish belongs to the phylum Cnidaria. Cnidoblasts bearing tentacles are present around the mouth. These tentacles are useful for capturing the prey whereas cnidoblasts inject the toxin in the body of prey. Those are useful for protection too. The release of the contact and its contact with the skin hence causes irritation when our body comes in contact with the jelly fish.

Chordates have a supporting notochord in the body. In sub-phylum Vertebrata, the notochord present in embryos gets replaced by a cartilaginous or bony vertebral column in adults. But in cephelochordates, notochord persists throughout life as such and in urochordates, notochord is present only in larval stages and absent in adults. Thus, it can be said that all vertebrates are chordates but all chordates are not vertebrates.

Through the view point of evolution, Balanoglossus is considered as connecting link between non-chordates and chordates. This animal shows the characters of both the groups. It is a chordate since it has a notochord, tubular nerve cord and gill slits. The invertebrates character includes the phosphogens and larva.

Reptiles are poikiolotherms, which means they are cold blooded animals. Cold-blooded animals do not maintain a constant body temperature. They get their heat from the outside environment, so their body temperature fluctuates, based on external temperatures. Hence, body temperature of reptiles is not constant.

Collar cells

Explanation: The specialized type of cells present in the body of sponges belonging to the Phylum Porifera are known as the collar cells.

Earthworm

Explanation: Earthworms belong to the Phylum Annelida. They are triploblastic, bilaterally symmetrical and eucoelomate.

Star fish

Explanation: Star fish belongs to the Phylum Echinodermata. Animals belonging to this phylum have a good ability of regeneration.

Mammalia

Explanation: Bats are warm-blooded and show the presence of mammary glands.

1. Hydra

Kingdom- Animalia

Body organization- Cell tissue

Body symmetry- Radial symmetry

Body cavity- Acoelomate

Phylum- Cnidaria

2. Jellyfish

Kingdom- Animalia

Body organization- Cell tissue

Body symmetry- Radial symmetry

Body cavity- Acoelomate

Phylum- Cnidaria

3. Planaria

Kingdom- Animalia

Body organization- Tissue grade

Body symmetry- Bilateral symmetry

Body cavity- Acoelomate

Phylum- Platyhelminthes

4. Round worm

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Annelida

5. Butterfly

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Arthropoda

6. Earthworm

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Annelida

7. Octopus

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Mollusca

8. Starfish

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Echinodermata

9. Shark

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Pisces

10. Frog

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Amphibia

11. Wall lizard

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Reptilia

12. Pigeon

Kingdom- Animalia

Body organization- Organ system grade

Body symmetry- Bilateral symmetry

Body cavity- Eucoelomate

Phylum- Aves

Jellyfish

Earthworm

Tapeworm

Fish