The photos in this gallery include various protists (mostly single-celled organisms, including algae), mollusks (e.g., snails), insects and insect larvae, roundworms, flatworms, segmented worms, and other small multicellular organisms. Most are from fresh and salt water environments.
Hydra with a Bud 
Stentor on Strand of Spirogyra 
Aquatic Segmented Worm 
Daphnia 
Daphnia 
Daphnia 
Aquatic Segmented Worm 
Aquatic Segmented Worm 
Aquatic Segmented Worm 
Aquatic Flatworm 
Aquatic Flatworm 
Aquatic Flatworm 
Aquatic Flatworm 
A Hypotrich (Single-Celled Ciliate) 
Paramecium caudatum 
Aquatic Segmented Worm 
Aquatic Round Worm 
Head of Aquatic Insect Larva 
Aquatic Insect Larva