Many fish species have unusually large, prominent lips. This feature has evolved in both freshwater and saltwater fish, and in many different climate zones.
Biologists who specialize in fish are called ichthyologists. They have developed many theories as to why fish might evolve with big lips. Some speculate that those fish with large lips are able to hunt or forage for food more easily than fish with smaller lips in the same environmental niche.
Others think that enlarged lips help fish frighten off predators. Still others think that fish with larger lips use them to attract mates. All of these theories might be true.
10 Fish With Big Lips
Here are 10 species of fish with big lips.
Probably the best known fish with big lips is the piranha, one of several related species in the Serrasalmidae family. Pirhana are tropical freshwater fish found in the Amazon and other rivers in South America.
The name piranha comes from a combination of Tupi words, pira and nya, which, together, mean biting fish. The name is appropriate, as piranha have formidable jaws of twenty or more sharp teeth. The jaw of the piranha is controlled by large muscles, enabling it to deliver a powerful bite.
In addition to its powerful jaw and teeth that have a strong bite force, the piranha has very large lips. The piranha has a reputation as a terrifying predator, because of its aggressive feeding habits and its enormous teeth. Two of the piranha species with particular reputations for aggressiveness are the black piranha, and the red-bellied piranha.
It is a very popular aquarium fish, despite, or perhaps because of, its reputation. In an aquarium, some piranha species can grow up to a foot long. Although the piranha is voracious in the wild, it does not often attack humans.
Another commonly known fish with large lips is the pacu. Like the piranha, it is a member of the Serrasalmidae family. It is also native to tropical waters in South America. However, it has been introduced to other parts of the world, and in some places, like New Guinea, it has become a serious nuisance, and driven out local species of fish.
Although the pacu is related to the piranha, it is a vegetarian, eating plants that grow in rivers. The pacu can grow much larger than the piranha and can reach lengths of 3 feet or more and weights nearing 100 pounds.
3. Humphead Wrasse
The humphead wrasse (Cheilinus undulates) is a fish with truly gigantic lips. It is a saltwater fish found in coral reefs in the Indian and Pacific Oceans. The humphead wrasse is also sometimes called the Napoleon wrasse or the Napoleon fish.
The humphead wrasse can grow up to 6′ long and weigh up to 400 pounds. It eats smaller fish, shrimp, worms, crabs, and other small sea animals that live on coral reefs.
Humphead wrasse can vary in color from dark green to bright blue, although they tend to have two black lines under their eyes.
Humphead wrasse are unusual in that they are born female, and then some individuals change to males when they mature. This process is called protogynous hermaphroditism. Scientists don’t understand why some wrasse change and others do not. Humphead wrasse mature very slowly, becoming adults at age 5 or 6.
Several different species of fish with large lips are called carp. All are members of the Cyprinidae family. These freshwater fish are native to Europe and Asia, and have been introduced to North America and Africa, where they are often an invasive species.
Carp are omnivorous, meaning they will eat anything.. They come in a variety of colors, and can grow up to three feet long.
Carp are unusual because they can live in water with low oxygen levels, including water covered with ice and stagnant water, where the oxygen is not replenished. Instead of bringing in oxygen through the gills and expelling carbon dioxide, carp convert glycogen into lactic acid, which they then metabolize into carbon dioxide and ethanol.
While they may look like giant goldfish to some, koi are a kind of carp. Unlike many carp species, they are usually quite colorful, and are popular fish for aquariums and outdoor ponds. These popular fish are able to eat nearly anything, are very easy to care for and can live for a very long time.
6. Sweetlips Fish
The sweetlips fish is a species related to the grouper. It lives in the tropical waters and coral reefs of the Indian Ocean.
The sweetlips fish can grow to over two feet long and weigh over four pounds. It comes in a number of varieties with prominent spots or stripes.
They are difficult to raise in captivity, and so aren’t often found in aquariums. They eat mostly crustaceans and insects, as well as worms.
7. Paddletail Snapper
The paddletail snapper lives in tropical oceans on reefs. This fish has colorful black and red markings, and prominent lips. this big-lipped fish eats small marine animals like worms, shrimp, crabs, octopuses and other smaller fish.
Gouramis are a freshwater fish from Asia. They live in shallow, slow-flowing or stagnant bodies of water. Gouramis have very large lips, and often “kiss” other gouramis. The two fish face each other mouth to mouth. This unusual behavior can happen both when the fish are fighting and when they are mating.
Gouramis can grow quite large, with some specimens growing to over a foot in size. They are usually a shiny green color, but an albino variety is also available and can be purchased for aquariums.
The gourami has evolved an unusual adaptation, the labyrinth organ. This organ is similar to a lung, and allows the fish to take in air through its mouth at the surface of water. The labyrinth organ allows the gourami to breathe and survive in what might otherwise be oxygen-poor habitats.
9. Saltwater Angelfish
There are nearly 90 different species of saltwater or marine angelfish. Saltwater angelfish have very large lips.
All saltwater angelfish belong to the Pomacanthidae family. Despite looking somewhat like freshwater angelfish, the different sorts are not related, and are classified differently by marine biologists.
Most types of saltwater angelfish are found on coral reefs in the tropical waters of the Pacific, Indian and Atlantic Oceans. The different sorts of saltwater angelfish eat a wide variety of food on the reef, including sponges, worms, plankton, plants and various ocean invertebrates.
Saltwater angelfish tend to be quite colorful, and can be found in a rainbow of every shade and hue. The queen angelfish is neon blue and yellow, with shiny orange and purple markings. It can grow to be 18 inches long.
Many kinds of marine angelfish can be raised in aquariums, and are popular with people who raise fish for a hobby.
10. Freshwater Angelfish
There are three different species of freshwater angelfish: Pterophylum leopoldi, Pterophylum altum, and Pterophylum scalare. All three species are originally from the Amazon River and its tributaries. All three species have prominent beak-like points to their mouths and big lips in relation to their body size.
Angelfish are quite colorful and very popular as aquarium fish, being easy to raise, and fairly easy to breed in captivity. One unusual aspect about breeding freshwater angelfish is that they form permanent pair bonds.
If one fish dies or is removed from the aquarium, the remaining fish refuses to breed with any other angelfish that may be placed in the aquarium as a replacement.
They are not related to saltwater angelfish, and are classified differently by biologists.