Animal Kingdom Table for Comparison of Characters

In the animal kingdom, there is a vast diversity of species with unique characteristics and traits. Scientists have classified these animals into different groups based on their shared characteristics, allowing us to compare and contrast them. Here is a table that highlights some key characteristics of different animal groups:

Phylum Porifera (Sponges)
- Simplest and most primitive animals
- Lack tissues and organs
- Filter feeders
- Have a porous body with numerous openings called ostia
- Sessile, attached to a substrate

Phylum Cnidaria (Jellyfish, Corals, Anemones)
- Radial symmetry
- Diploblastic (two germ layers)
- Possess specialized cells called cnidocytes that contain stinging structures called nematocysts
- Have a gastrovascular cavity with a single opening (mouth/anus)

Phylum Platyhelminthes (Flatworms)
- Bilateral symmetry
- Triploblastic (three germ layers)
- Some are free-living, while others are parasitic
- Lack a body cavity (acoelomate)
- Some are hermaphroditic

Phylum Nematoda (Roundworms)
- Bilateral symmetry
- Triploblastic
- Pseudocoelomate (body cavity not completely lined with mesoderm)
- Many are parasites
- Complete digestive system

Phylum Annelida (Segmented Worms)
- Bilateral symmetry
- Triploblastic
- Coelomate (body cavity completely lined with mesoderm)
- Segmented body with repeated units called segments
- Well-developed circulatory and nervous systems

Phylum Arthropoda (Insects, Crustaceans, Arachnids)
- Bilateral symmetry
- Triploblastic
- Coelomate
- Exoskeleton made of chitin
- Jointed appendages

Phylum Mollusca (Snails, Clams, Squids)
- Bilateral symmetry
- Triploblastic
- Coelomate
- Soft-bodied animals with a muscular foot, visceral mass, and mantle
- Some have a protective shell

Phylum Chordata (Vertebrates)
- Bilateral symmetry
- Triploblastic
- Coelomate
- Possess a notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some stage of their development
- Divided into subphyla: Urochordata (tunicates), Cephalochordata (lancelets), and Vertebrata (fish, amphibians, reptiles, birds, mammals)

Key Comparisons:
- Body Symmetry: Animals can have radial or bilateral symmetry, which affects their overall body plan and organization.
- Germ Layers: Animals are classified as diploblastic (two germ layers) or triploblastic (three germ layers), which influences the complexity of their body structures and systems.
- Body Cavity: Animals can be acoelomate (lack a body cavity), pseudocoelomate (body cavity not completely lined with mesoderm), or coelomate (body cavity completely