An invertebrate lacks a bony internal skeletal system; instead, many invertebrates have a hard outer shell, like bivalves and crabs, while others have a fluid-filled, hydrostatic skeleton, such as jellyfish and worms. The warmer climate of Florida and its large bodies of water offer natural habitats on both land and water for invertebrates to thrive. Water invertebrates native to Florida live in the saltwater surrounding the state and the freshwater lakes, rivers and marshes within it. This type of invertebrate lives in the Atlantic Ocean, the Gulf of Mexico, the marshy waters of the Everglades and freshwater lakes, such as Lake Okeechobee. Land invertebrates are found in the flora, fauna, sands and dirt.
Porifera, or sponges, are found in the shallow-to-deep waters just off the coast of Florida. You can see them living by themselves or in colonies, such as those among the coral reefs. Sponges help keep the waters surrounding Florida clear and clean, as they act as a filter. Sponges filter out organisms and other microorganisms that may reduce visibility and cause cloudy water.
Cnidaria is a classification of invertebrates that lives in the waters just off the state’s shoreline. Animals in this classification include jellyfish, sea anemones, corals and hydrozoa. Visitors often see Portuguese man-of-war, which wash up on the beaches in Florida and can pose a danger to people and animals walking the beaches barefoot. Other types of jellyfish in the saltwater around Florida include cannonball, moon and sea nettle jellyfish. Coral compose a major role in the design of coral reefs and provide a home for smaller fish to live and hide from predators. Reef coral has a symbiotic relationship with microscopic plants that live within its tissues.
Mollusca, or, as they are more commonly called, the mollusk, is a classification of animals with species living in both water and on land in Florida. The largest class of mollusks is the gastropods, which are animals with a single shell, an identifiable head and a flattened foot. Florida gastropods include snails, periwinkles, conch, whelks, limpets, abalone, slugs and sea slugs. This type of invertebrate can retract its body into its shell and hide from predators. Other mollusks native to Florida include chitons, bivalves and cephalopods.
Both marine and earthworms are classified as annelida, and you can find them on land and water in Florida. Marine worms resemble earthworms, as they are segmented; however, in the water they take on many different forms and appearances. Examples of marine worms include the Christmas tree, large-eyed feather duster, orange and the red-rim.
The invertebrates classified as arthropoda include crabs and insects; they make up the largest classification of invertebrates in Florida. Animals in this category include: crustaceans, millipedes, horseshoe crabs, arachnid, insects, dragonflies, beetles and ants. More than 150 different species of dragonflies exist in Florida that prey primarily on mosquitoes, and more than 100 butterflies inhabit the state year-round.