The marsh contains millions of invertebrates from butterflies to shrimp. Insects like mosquitoes, earthworms, dragonflies, grasshoppers and diving beetles dominate marshland. However, invertebrates aren’t relegated to life on land within the marsh environment. Mollusks like snails, oysters and conch as well as crustaceans like crabs, shrimp and hermits meander back and forth between marsh water and land, particularly in brackish or saltwater marshes.