Kingdom Classification - Animalia

Characteristics

Multicellular: Organisms in this kingdom are composed of many cells.
Eukaryotic: They possess a true nucleus and other membrane-bound organelles.
Heterotrophic: They obtain nutrients by ingesting other organisms or organic matter.
No Cell Wall: Animal cells do not have a cell wall.
Motility: Most animals are capable of locomotion.
Reproduction: Primarily reproduce sexually.

(a) Vertebrates

Vertebrates are animals that possess a backbone or spinal column.

Key Characteristics:
- Presence of a vertebral column (backbone).
- Well-developed internal skeleton.
- Complex nervous system with a brain enclosed in a cranium.
- Bilateral symmetry.
- Closed circulatory system.
Examples: Fish, Amphibians, Reptiles, Birds, Mammals.

(b) Invertebrates

Invertebrates are animals that do not possess a backbone or spinal column. They constitute the vast majority of animal species.

9 Major Phyla

Porifera (Sponges):
- Characteristics: Simplest multicellular animals, sessile, porous body, filter feeders.
- Example: Sponges (e.g., Sycon).
Cnidaria (Coelenterata):
- Characteristics: Radial symmetry, stinging cells (cnidocytes), sac-like body with a single opening (mouth/anus).
- Example: Jellyfish, Hydra, Sea Anemones, Corals.
Platyhelminthes (Flatworms):
- Characteristics: Dorsoventrally flattened body, bilateral symmetry, acoelomate (no body cavity), parasitic or free-living.
- Example: Tapeworms, Planaria, Liver Fluke.
Nematoda (Roundworms):
- Characteristics: Cylindrical, unsegmented body, pseudocoelomate (false body cavity), many are parasitic.
- Example: Ascaris, Filarial worms.
Annelida (Segmented Worms):
- Characteristics: Segmented body, true coelom, well-developed organ systems.
- Example: Earthworms, Leeches.
Arthropoda:
- Characteristics: Jointed legs, chitinous exoskeleton, segmented body, most diverse phylum.
- Example: Insects (e.g., Cockroach, Butterfly), Spiders, Crabs.

Largest Phylum Arthropoda is the largest phylum in the animal kingdom, comprising more than 80% of all known animal species.

Mollusca:
- Characteristics: Soft body, usually protected by a shell, muscular foot, mantle.
- Example: Snails, Clams, Octopuses.
Echinodermata:
- Characteristics: Spiny skin, radial symmetry (in adults), water vascular system.
- Example: Starfish, Sea Urchins.

Characteristics

Multicellular: Organisms in this kingdom are composed of many cells.

Eukaryotic: They possess a true nucleus and other membrane-bound organelles.

Heterotrophic: They obtain nutrients by ingesting other organisms or organic matter.

No Cell Wall: Animal cells do not have a cell wall.

Motility: Most animals are capable of locomotion.

Reproduction: Primarily reproduce sexually.

(a) Vertebrates

Vertebrates are animals that possess a backbone or spinal column.

Key Characteristics:

Presence of a vertebral column (backbone).
Well-developed internal skeleton.
Complex nervous system with a brain enclosed in a cranium.
Bilateral symmetry.
Closed circulatory system.

Examples: Fish, Amphibians, Reptiles, Birds, Mammals.

(b) Invertebrates

Invertebrates are animals that do not possess a backbone or spinal column. They constitute the vast majority of animal species.

Porifera (Sponges):

Characteristics: Simplest multicellular animals, sessile, porous body, filter feeders.
Example: Sponges (e.g., Sycon).

Cnidaria (Coelenterata):

Characteristics: Radial symmetry, stinging cells (cnidocytes), sac-like body with a single opening (mouth/anus).
Example: Jellyfish, Hydra, Sea Anemones, Corals.

Platyhelminthes (Flatworms):

Characteristics: Dorsoventrally flattened body, bilateral symmetry, acoelomate (no body cavity), parasitic or free-living.
Example: Tapeworms, Planaria, Liver Fluke.

Nematoda (Roundworms):

Characteristics: Cylindrical, unsegmented body, pseudocoelomate (false body cavity), many are parasitic.
Example: Ascaris, Filarial worms.

Annelida (Segmented Worms):

Characteristics: Segmented body, true coelom, well-developed organ systems.
Example: Earthworms, Leeches.

Arthropoda:

Characteristics: Jointed legs, chitinous exoskeleton, segmented body, most diverse phylum.
Example: Insects (e.g., Cockroach, Butterfly), Spiders, Crabs.

Largest Phylum Arthropoda is the largest phylum in the animal kingdom, comprising more than 80% of all known animal species.

Mollusca:

Characteristics: Soft body, usually protected by a shell, muscular foot, mantle.
Example: Snails, Clams, Octopuses.

Echinodermata:

Characteristics: Spiny skin, radial symmetry (in adults), water vascular system.
Example: Starfish, Sea Urchins.

Animalia

Kingdom Classification - Animalia

Characteristics

(a) Vertebrates

(b) Invertebrates

9 Major Phyla

On this page

Animalia

Kingdom Classification - Animalia

Characteristics

(a) Vertebrates

(b) Invertebrates

9 Major Phyla

On this page