Freshwater invertebrates typically have an open circulatory system, where blood flows freely through the body cavity, rather than being confined to vessels.

Insects are the most diverse group of freshwater invertebrates, with a wide range of species adapted to various habitats and ecological niches.

Water fleas are small crustaceans commonly found in freshwater habitats, known for their rapid reproduction and role in the aquatic food chain.

Gills are specialized structures in freshwater invertebrates that facilitate the exchange of oxygen and carbon dioxide between the organism and the surrounding water.

Blackfly larvae are filter feeders, using specialized mouthparts to strain food particles from the water.

Freshwater invertebrates play various ecological roles, including primary production through photosynthesis (e.g., some aquatic insects), secondary consumption of organic matter, and decomposition of dead organisms.

Crayfish are burrowing freshwater invertebrates, constructing and inhabiting burrows in the substrate for shelter and protection.

Freshwater snails typically move by crawling on surfaces using a muscular foot.

Leeches are parasitic freshwater invertebrates that attach themselves to other organisms and feed on their blood.

Freshwater mussels are filter feeders, primarily consuming bacteria and other microorganisms suspended in the water.

Dragonflies undergo complete metamorphosis, with distinct larval and adult stages.

Freshwater invertebrates are sensitive to changes in water quality, making them valuable bioindicators for assessing the health of aquatic ecosystems.

Oceans are marine habitats and not typically considered freshwater environments for invertebrates.

The exoskeleton in freshwater invertebrates primarily serves as a protective barrier against physical damage and predators.

Caddisflies are known to exhibit parental care, with some species constructing protective cases for their eggs and larvae.