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.
Second Grade: Focus on Systems and System Models; Energy and Matter
Earth and Space Sciences: Students develop an understanding of the distribution and role of water and wind in weather, shaping the land, and where organisms live. Wind and water can also change environments, and students learn humans and other organisms can change environments too. Students develop an understanding of changing patterns in the sky including the position of Sun, Moon, and stars, and the apparent shape of the Moon.
Earth and Space Standards
Observe and explain the Sun’s position at different times during a twenty-four-hour period and changes in the apparent shape of the Moon from one night to another.