Invertebrate Animals Classification

Characteristics of Animals

• All animals share the characteristic of feeding on organic molecules.

Classification of Animal Kingdom

• The Animal Kingdom divides into two primary groups: vertebrates (with backbone) and invertebrates (without backbone).

Invertebrates vs. Vertebrates

• Invertebrates: Animals lacking a backbone.
• Vertebrates: Animals possessing a backbone.

Groups of Invertebrates

• There are four main groups of invertebrates:
  • Nematodes
  • Annelids
  • Molluscs
  • Arthropods

Features of Arthropods

• Common characteristic among arthropods: presence of jointed legs.

Phyla of Arthropods

• Four identified phyla include:
  • Crustacea
  • Myriapods
  • Arachnids
  • Insects

Nematodes

• Nematodes, such as hookworms, have bodies adapted for feeding and reproduction.
• They typically exist as parasites within the guts of host animals.

Annelids

• Annelids are characterized by a segmented body and chaetae (bristle-like structures).
• Their chaetae assist in movement, and a mucus layer prevents desiccation.

Molluscs

• Molluscs possess hard shells to protect their soft bodies and retain water.

Myriapods

• Myriapods feature antennae for sensory perception in their dim environments.
• Numerous body segments aid in movement under vegetation and rocks.
• Their mouthparts have hard edges, suitable for biting food.
• A hard exoskeleton offers protection from predators, while a waterproof body covering supports terrestrial life.

Example of a Myriapod

• Millipedes represent a common example of myriapods.

Insect Characteristics

• Every insect has three distinct body segments: head, thorax, and abdomen.
• All insects have three pairs of legs.

Test your knowledge on the classification of invertebrate animals with these flashcards. Explore the characteristics that define all animals and delve into the division between vertebrates and invertebrates. Perfect for biology students seeking to strengthen their understanding of animal classification.