Fish Species Starting with U
Browse all aquarium fish species with scientific names beginning with "U". Each profile includes care requirements, water parameters, tank size recommendations, and compatibility information for freshwater, marine, and brackish species.
Welcome to the species index for the letter 'U', where you'll discover a fascinating variety of fish including both popular community dwellers and unique rarities. Although our database currently doesn't feature any species starting with 'U', notable examples in the broader fishkeeping world include the Upside-Down Catfish (Synodontis nigriventris) and the Unicorn Tang (Naso unicornis). This section highlights the diversity of the aquatic realm, showcasing both striking additions to your aquarium and historical species.
3 species found
Uaru (Triangle cichlid)
Uaru amphiacanthoides
Uaru are big, mellow Amazon cichlids with that neat disc-and-triangle body shape and a surprisingly "gentle giant" vibe. They graze and pick at food all day, act super social when kept in a group, and they are famous for serious parent duty when they breed (both parents guard and tend the young).
Eastern mudminnow
Umbra pygmaea
Eastern mudminnows are tough little swamp-and-ditch survivors that can handle low oxygen and even gulp air when they need to. They spend a lot of time lurking in weeds and leaf litter, then suddenly dart out to nail small bugs and crustaceans. Not a flashy fish, but super cool if you like oddball native species with real personality.
Hairy pipefish
Urocampus carinirostris
This is a tiny, stick-thin pipefish that lives in seagrass and algae beds and uses its prehensile tail to hang on like a little underwater chameleon. The coolest part is the "hairy" fringing (little filaments) all over the body that breaks up its outline, and like other syngnathids the male carries the eggs in a brood pouch under the tail.