Invertebrates are animals that do not have a backbone. They make up the majority of the animal kingdom and come in a wide variety of shapes, sizes, and habitats. Invertebrates can be found in the oceans, freshwater, and on land.
Types of Invertebrates
There are several main groups of invertebrates:
Arthropods: These are the largest group of invertebrates and include insects, spiders, crustaceans, and centipedes. They have a hard exoskeleton and jointed legs.
Mollusks: This group includes snails, clams, octopuses, and squids. They have soft bodies and some have shells for protection.
Worms: This group includes segmented worms, flatworms, and roundworms. They can be found in a variety of environments, including soil, freshwater, and marine habitats.
Cnidarians: This group includes jellyfish, corals, and sea anemones. They have stinging cells called nematocysts to capture prey.
Echinoderms: This group includes starfish, sea urchins, and sea cucumbers. They have a spiny skin and a unique water vascular system.
Characteristics of Invertebrates
While invertebrates come in many shapes and sizes, they share some common characteristics:
No Backbone: Unlike vertebrates, invertebrates do not have a backbone or spinal column.
Diverse Body Plans: They exhibit a wide range of body shapes and structures, from the segmented bodies of insects to the soft bodies of mollusks.
Exoskeleton or Soft Body: Many invertebrates have an exoskeleton made of chitin, while others have soft, flexible bodies.
Diverse Locomotion: Invertebrates move in various ways, including crawling, swimming, and burrowing.
Varied Diets: They can be herbivores, carnivores, omnivores, or filter feeders, depending on their species.
Concepts of Earth Science: A student should understand and be able to apply the concepts, processes, theories, models, evidence, and systems of earth and space sciences. A student who meets the content standard should:
Develop an understanding of the cyclical changes controlled by energy from the sun and by Earth's position and motion in our solar system.