The False Scorpionfish (Centrogenys vaigiensis) is also known as the Prettyfins. The False Scorpionfish looks so much like scorpionfishes that it was originally described as a species of Scorpaena, fooling humans just as well as predators who would never risk trying to eat a highly venomous true scorpionfish. However, it has no venom!

Wrasses (image 1) have protractile mouths, that usually come with separate jaw teeth that jut outwards.

Wrasses and Parrotfish (family Labridae) are some of the most colorful fish in the sea, also exhibiting sexual dimorphism and having multiple different colors and patterns as they mature and/or change sex. Most labrids are protogynous hermaphrodites within a haremic mating system. Juvenile wrasses of some species can be either male or female (known as initial-phase individuals), but the largest adults become territory-holding, dominant (terminal-phase) males.

Sex change in wrasses is generally female-to-male, but experimental conditions have allowed for male-to-female sex change. Placing two male Bluestreak Cleaner Wrasses (Labroides dimidiatus) in the same tank results in the smaller of the two becoming female again. Additionally, while the individual to change sex to male will generally be the largest female, evidence also exists of the largest female instead choosing to remain female in situations in which she can maximize her evolutionary fitness (ie reproduce the most) by refraining from changing sex.

A well-known example of the reproductive behavior of wrasses is found in the California Sheephead (Bodianus pulcher). All California Sheephead are hatched female and will morph into their male form at various stages in their lifecycle; the age of the transition will depend on environmental factors, such as safety and food supply. Female Sheephead are silvery or dull pink with white undersides, while males are larger, with a black tail and head sections, wide reddish orange midriffs, red eyes, and fleshy forehead bumps. The species can live for over 50 years. Overfishing has caused this species to heavily decline, as fisheries tend to remove the largest fish from the population, which, in the case of the California Sheephead, are all males.

California Sheephead are one of the few animals able to hunt and feed on sea urchins. They have protruding canine teeth used to pry hard-shelled animals from rocks, powerful jaws, and modified throat bones (throat plates) to grind tough prey into small pieces.

Wrasses are highly intelligent and are one of the few groups of Actinopterygiians known to use tools. 21 species out of 8 genera of wrasse have been recorded using large rocks or hard coral as "anvils", upon which they break open hard-shelled prey items. At least some of these species will designate a particular rock or coral specifically for this purpose, remembering its location and returning to it when something needs smashing.

In a 2019 study, Bluestreak Cleaner Wrasses passed the mirror test, the first fish to do so. However, the mirror test's inventor, American psychologist Gordon G. Gallup, hypothesized that the fish were most likely trying to scrape off a perceived parasite on another fish and that they did not demonstrate self-recognition. The authors of the study retorted that because the fish checked themselves in the mirror before and after the scraping, this meant that the fish had self-awareness and recognized that their reflections belonged to their own bodies. In a 2024 study, Bluestreak Cleaner Wrasses were reported to initially show aggression to wrasse photographs sized 10% larger or 10% smaller than themselves, regardless of size. However, after viewing their own reflections in a mirror, they avoided confronting photographs 10% larger than they were, showing self-awareness and recognition of their own size and strength.

Cleaner wrasses are the best-known of the cleaner fish. They live in a cleaning symbiosis with larger, often predatory, fish, grooming them and subsequently benefiting by consuming the dead tissue, scales, and ectoparasites that they remove. "Client" fish congregate at wrasse "cleaning stations" and wait in line for the cleaner fish to attend to them. The cleaners will even swim into the open mouths and gill cavities of predatory fish to clean them. Cleaner wrasses have rarely been observed being eaten by predators, possibly because parasite removal is more important for predator survival than the short-term gain of eating a cleaner. Cleaner wrasses are sometimes employed by humans as cleaner fish to combat sea-lice infestations on salmon farms.

The “beaks” of parrotfish (tribe Scarini) are actually numerous teeth arranged in a tightly packed mosaic on the external surface of their jaw bones.

The largest species of parrotfish, the Green Humphead Parrotfish (Bolbometopon muricatum) (see gif above) can grow to lengths of 1.5 m (4.9 ft) and weigh up to 75 kg (165 lb). They live in groups that can number up to 75 individuals, sleeping together at night among corals, or in caves and shipwrecks.

Some parrotfish species, such as the Queen Parrotfish (Scarus vetula), secrete a mucus cocoon, particularly at night. Prior to going to sleep, they will extrude mucus from their mouths, forming a protective cocoon that envelops their body, hiding their scent from potential predators, and allowing the fish to escape as soon as its cocoon is disturbed. The skin itself is covered in another mucous substance which has antioxidant properties helpful in repairing bodily damage, repelling parasites, and providing protection from UV light.

As its common name would imply, the bones of the Greenbone (Odax pullus) are a bright blue-green. Their name in Māori is Rarī, and the species is a troublemaker in folklore. The name Rarī over time became used to describe people who were troublemakers as well.

Sand Lances (family Ammodytidae) convergently evolved several features with chameleons, including independently moving eyes with specialized focusing lenses, and a long, ballistic tongue that can quickly dart out of their mouth at high velocity.

Stargazers (family Uranoscopidae) (image 2) are ambush predators with top-mounted eyes and upward facing mouths. They bury their bodies beneath the sand with only their eyes and mouths protruding, waiting for small fish and invertebrates to pass overhead. Some species even have a worm-shaped lure, a convergent feature with anglerfishes, growing out of the floors of their mouths, which they can wiggle to attract prey's attention. They are venomous, with two large spines situated behind their opercles and above their pectoral fins.

Stargazer species within the genera Astroscopus and Uranoscopus can deliver electric shocks. Astroscopus species have a single electric organ consisting of modified eye muscles, while Uranoscopus species have theirs derived from sonic muscles. These two genera within stargazers represent one of eight independent evolutions of bioelectrogenesis. They are unique among electric fish in not possessing electroreceptors, meaning that they do not use an electric sense to locate prey, only to shock their prey.

Most stargazers are fairly small, but the Giant Stargazer (Kathetostoma giganteum) can reach up to 90 cm (3 ft) long.

Male and female Speckled Sandperches (Parapercis hexophtalma) (image 3) were once thought to be different species, as they have different markings and sizes. They are one of the many Labriformes that begin life as females and change to males as they grow, changing their markings in the process.