Explore 51 Fish That Start with U (Common Names)

Uaru Cichlid
chonlasub woravichan/Shutterstock.com

Written by Patrick MacFarland

Published: August 5, 2023

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From crabs to lobsters and seahorses to humpback whales, under the ocean, there are a host of many living creatures. Among those creatures that inhabit the seas are fish. According to the National Oceanic and Atmospheric Association (NOAA), there are more than 20,000 species of living fish that exist underneath our waters. It’s hard to keep track of the number, especially if you want to alphabetize them!

Let’s explore 51 fish that start with the letter U and highlight some of the most popular and common ones, in no particular order.

#1 Uaru

Uaru Cichlid

The uaru is a colorful fish that can live up to 8-10 years.

The uaru is a weird-looking, triangle-shaped fish. Uaru means toad in the Amazonian language. The fish lives in the Orinoco and Amazon rivers of South America. They are usually not the most colorful and vibrant of aquarium fish, but they have become popular over time. The uaru are also intelligent fish that feed off crustaceans, worms, and insects.

#2 Uganda Nothobranch

A very colorful male Nothobranchius rachovii killifish.

Found in the bodies of water in Kenya and Uganda, this fish is a colorful one that can easily be a popular aquarium fish.

This species of fish resides in Kenya and Uganda. It’s a freshwater fish that is small and known for its bright colors, usually red or blue. The most fascinating thing about these colorful fish, though, is that you can sometimes find them in pools, drainage areas, and swamps.

#3 Ukrainian Brook Lamprey

river lamprey, isolated on a white background, a species of predatory jawless fish in the family lampreys

The Ukrainian brook lamprey calls home fresh bodies of water like brooks, springs, and lakes around Eastern Europe.

This fish is a species of lamprey that lives mainly in the Balkan region of Europe, as well as Eastern Europe. Specifically, you can find the Ukrainian brook lamprey in the mountainous regions of these countries in fresh bodies of water. This long fish is usually prey for other larger fish.

#4 Umbrella Cichlid

Apistogramma borelli Umbrella cichlid fish

The umbrella cichlid is usually an aquarium fish, but it naturally calls waters in South America home.

Found in rivers in South America, the umbrella cichlid is a small, colorful, yellow fish. They usually eat insects and crustaceans and when they breed, it’s usually because of the excess of water from the heavy rains.

#5 Umbrella Conger

Conger (Conger conger) Granada, Spain

The umbrella conger is a species of conger that is all the way in the depths of the Pacific Ocean.

The umbrella conger resides at the sandy bottom of the Pacific Ocean, usually near Australia, Papua New Guinea, and New Zealand. It’s a long fish that can grow up to 17 inches in length, which makes it look like an eel.

#6 Underjaw Kingfish

Guelly jack, white trevally or striped jack (Pseudocaranx dentex) El Hierro, Spain

Another name for the underjaw kingfish is white trevally.

The underjaw kingfish, which has several other names, makes its home in tropical or warm regions of oceans. Specifically, it lives in the Pacific, Atlantic, and Indian Oceans. It has a metallic green color, with its fins a yellowish color. Interestingly enough, if you are an avid fisherman, the underjaw kingfish makes for good food. But beware, they are good fighters!

#7 U-Mark Sandperch

Snyder's Grubfish or Blackfin sandperch (Parapercis snyderi) in coralreef, Lembeh strait, North Sulawesi, Indonesia

The U-mark sandperch, or Snyder’s grubfish, is a colorful fish that lives in several regions in the Pacific Ocean.

The U-mark sandperch generally calls home areas around Southern Japan and Australia, near Queensland. They inhabit lagoons and their food consists of smaller fish and invertebrates. Although they are colorful and attractive to humans, they are not considered fish for consumption.

#8 Undulate Painted Ray

Undulate Ray over white sand

The undulate painted ray is a species of ray that is slowly going extinct because of its popularity with fishermen.

This species of ray primarily lives in the Mediterranean Sea, but you may also find it in the North Atlantic near Ireland and England and all the way to South Africa. Because of its popularity in fishing, the IUCN lists this species as ‘endangered.’

#9 Undulated Moray

Undulated moray eel Oahu, Hawaii

The undulated moray is a colorful green fish that hides in reefs and is common in Hawaiian folk stories.

Found in the Indo-Pacific region of the seas, the undulated moray is a species of eel that has colorful yellow, green scales. A nocturnal fish that hides around reefs, they can move back and forth. Hawaiian folklore has attributed this moray as a protector of families, usually ancestors coming back as these fish.

#10 Ulrey’s Tetra

Broken-line Tetra (Hemigrammus ulreyi) or Astyanax sp. from Rio Paraguay Basin, Brazil

The Ulrey’s tetra is a small fish that comes from the tropical waters of Paraguay.

This is a very colorful fish that is common to find in aquariums across the world. Originally from Paraguayan waters, the Ulrey’s tetra is a small fish that loves hot temperatures. 

#11 Upland Bully

new zealand red fin bully

The upland bully is a small fish that lives in fresh water in New Zealand.

This freshwater fish calls the waters of New Zealand home. A dull brown, yellow color, the upland bully has small orange spots across its body. They are also very small fish that grow to only three inches. Believe it or not, even though the name may suggest it, the upland bully is not a bully at all. 

#12 Upside-Down Catfish

Catfish three pair of barbels macro view. Synodontis nigriventris blotched upside-down african predator fish, brown skin camouflage. Shallow depth of field photo.

This species of


comes from the Congo basin of Cameroon, as well as from the waters in Congo.

The upside-down catfish is a freshwater fish that got its name from the fact that, curiously, it feeds more easily when it’s upside down. It dwells in rivers that have a lot of vegetation. The upside-down catfish is gray-brown in color, but sometimes it can switch into an invertebrate to trick prey or escape from predators.

#13 Urchin Clingfish

Urchin clingfish in Bohol sea Philippines

Found in the Pacific and Indian oceans, the urchin clingfish is a small fish with a red-brown body and yellow lines.

Let’s start off by stating the obvious. This is a very weird-looking fish. The urchin clingfish can only grow to about two inches. It has a very elongated body with dark red scales and three yellow lines along its body. They are tropical fish, usually found in the Indo-Pacific region of the world.

#14 Unicornfish

The short-nosed unicornfish or spotted unicornfish (Naso brevirostris)  is a species of unicornfish in the family Acanthuridae.

The unicornfish has a horn between its eyes, which is how it got its name.

We come to a very colorful and interesting-looking fish on our list. Unicornfish prefer to hide out in coral reefs. The horn between the eyes of this fish gives it its name. They are colorful-looking fish of blue and green (sometimes silver too) found near coral reefs in the Pacific and Indian Oceans.

#15 The Largest Fish That Starts with U — The Utah Sucker

Aerial View of Swimming Beach on the Great Salt Lake, Utah

Utah suckers call home post-Lake Bonneville areas, like the Great Salt Lake.

Now, let’s discuss the largest fish that starts with the letter U. That prize goes to the Utah sucker. The Utah sucker is a freshwater fish that mainly lives in the Snake River and post-Lake Bonneville areas in the United States. It can grow from 15 to a whopping 25 inches in length. Having a mixture of colors, the Utah sucker has been in decline in recent years due to habitat destruction along the river. An article in the American Fisheries Society Symposium stated that habitat recovery and conservation efforts are critical for the Utah sucker to survive.

Other Fish That Start with the Letter U

Of course, those aren’t the only fish in the world that start with U. We list others below.

  1. Upper Zambezi yellowfish
  2. Uruguayan eartheater
  3. Utah Lake sculpin
  4. U-spot wrasse
  5. Unicorn crestfish
  6. Unicorn leatherjacket
  7. Unarmored threespine stickleback
  8. Umatilla dace
  9. Umpqua chub
  10. Umpqua dace
  11. Umpqua squawfish
  12. Unarmed dwarf monocle bream
  13. Unicolor moray
  14. United-lip gudgeon
  15. Uncinate sculpin
  16. Upjaw barb
  17. Upper Grijalva livebearer
  18. Upper Zambezi labeo
  19. Upper Zambezi squeaker
  20. Uruguay river sprat
  21. Uncombed blenny
  22. Undistinguished sabretooth
  23. Unicorn grenadier
  24. Unicorn icefish
  25. Unicorn sole
  26. Uruguay tetra
  27. Union snook
  28. Upside-down goby
  29. Upside-down harptail blenny
  30. Upturned snout rattail
  31. Usumacinta buffalo
  32. Usangu lampeye
  33. Ussuri catfish
  34. Ussuri sharpbelly
  35. Usumacinta cichlid
  36. Usumacinta sea catfish
  37. Utah chub


And there you have it, a total of 51 fish that start with the letter U. Some of them have hard-to-pronounce names while others have funny names. Some of them are named after people and others after countries. All of these fish are unique, which contribute to the ecosystem in a positive way.

Summary of Fish That Start with the Letter U

Fish with Common Names That Start with the Letter U

Common Fish NameScientific Name
UaruUaru amphiacanthoides
Uganda nothobranchNothobranchius ugandensis
Ukrainian brook lampreyEudontomyzon mariae
Umbrella cichlidApistogramma borellii
Umbrella congerGnathophis umbrellabius
Underjaw kingfishPseudocaranx dentex
U-mark sandperchParapercis snyderi
Undulate painted rayRaja undulata
Undulated morayGymnothorax undulatus
Ulrey’s tetraHemigrammus ulreyi
Upland bullyGobiomorphus breviceps
Upside-down catfishSynodontis nigriventris
Urchin clingfishDiademichthys lineatus
UnicornfishNaso brevirostris
Upper Zambezi yellowfishLabeobarbus codringtonii
Uruguayan eartheaterGymnogeophagus australis
Utah Lake sculpinCottus echinatus
U-spot wrasseHalichoeres stigmaticusis
Unicorn crestfishEumecichthys fiski
Unicorn leatherjacketAluterus monoceros
Unarmored threespine sticklebackGasterosteus aculeatus
Umatilla daceRhinichthys umatilla
Umpqua chubOregonichthys kalawatseti
Umpqua daceRhinichthys evermanni
Umpqua squawfishPtychocheilus umpquae
Unarmed dwarf monocle breamParascolopsis inermis
Unicolor morayEchidna unicolor
United-lip gudgeonPlatysmacheilus longibarbatus
Uncinate sculpinIcelus uncinalis
Upjaw barbCoptostomabarbus wittei
Upper Grijalva livebearerPoeciliopsis hnilickai
Upper Zambezi labeoLabeo lunatus
Upper Zambezi squeakerSynodontis woosnami
Uruguay river spratRamnogaster melanostoma
Uncombed blennyHaptoclinus apectolophus
Undistinguished sabretoothOdontostomops normalops
Unicorn grenadierCoelorinchus productus
Unicorn icefishChannichthys rhinoceratus
Unicorn soleAesopia cornuta
Uruguay tetraCheirodon interruptus
Union snookCentropomus unionensis
Upside-down gobyTrimma striatum
Upside-down harptail blennyMeiacanthus abditus
Upturned snout rattailCoelorinchus mycterismus
Usamacinta buffaloIctiobus meridionalis
Usangu lampeyeLacustricola usanguensis
Ussuri catfishPseudobagrus ussuriensis
Ussuri sharpbellyHemiculter lucidus
Usumacinta cichlidKihnichthys ufermanni
Usumacinta sea catfishPotamarius usumacintae
Utah chubGila atraria

Fish with Scientific Names That Start with the Letter U

Some fish have scientific names that start with the letter U. We’ve listed those below.

Fish with Scientific Names Starting with U
Uaru fernandezyepezi
Uegitglanis zammaranoi
Umbrina imberbis
Umbrina milliae (common name: Miller drum)
Umbrina reedi
Ungusurculus collettei
Ungusurculus komodoensis
Ungusurculus philippinensis
Ungusurculus riauensis
Ungusurculus sundaensis
Ungusurculus williamsi (common name: Williams’ viviparous brotula)
Uncisudis advena
Uncisudis longirostra
Uncisudis posteropelvis
Uranoscopus affinis
Uroconger erythraeus
Uropterygius genie
Uropterygius golanii
Uropterygius makatei
Uropterygius nagoensis
Uropterygius wheeleri
Urotrygon cimar
Ursinoscorpaenopsis kitai
Uranoscopus bauchotae
Uranoscopus chinensis
Uranoscopus crassiceps
Uranoscopus dahlakensis
Uranoscopus filibarbis
Uranoscopus fuscomaculatus
Uranoscopus guttatus (common name: Dollfus’ stargazer)
Uranoscopus marisrubri
Uranoscopus marmoratus
Utiaritichthys longidorsalis
Utiaritichthys sennaebragai

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About the Author

Patrick Macfarland is a writer at A-Z Animals primarily covering travel, geography, and history. Patrick has been writing for more than 10 years. In the past, he has been a teacher and a political candidate. He holds a Bachelor's Degree in Political Science from SDSU and a Master's Degree in European Union Studies from CIFE. From San Diego, California, Patrick loves to travel and try new recipes to cook.

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