Lizardfish

Quick Take

• One species of lizardfish goes by a name that has nothing to do with fish, and how it got that name remains a genuine mystery. The Bombay duck mystery →
• The deep-sea lizardfish carries a reproductive adaptation so unusual it redefines what a predator needs to survive in total darkness. Deep-sea hermaphrodite adaptations →
• Lizardfish have teeth in a place most fish don't, and this unusual feature changes how they hunt entirely. Teeth on the tongue →
• Juvenile lizardfish fooled scientists for years because their appearance hides something that even experts got completely wrong. Juveniles mistaken for new species →

The lizardfish family comprises around 57 different species (the most common of which are probably the inshore and brushtooth lizardfish) that live mainly near the coast.

Lizardfish have huge mouths full of teeth, including on their tongues. Despite the lizardfish’s sharp teeth, they are not very dangerous to humans. They are also neither poisonous nor venomous in any way. But even though lizardfish are edible, they are not usually caught for food or aquarium purposes.

3 Lizardfish Facts

• An American submarine called the USS Lizardfish was briefly active between 1944 and 1946. It was later transferred to the Italian Navy in 1960 and renamed the Evangelista Torricelli.
• The Bombay duck isn’t really a duck at all, but rather a species of lizardfish native to the Indian coast. It is not entirely clear how the species got its name.
• The juvenile lizardfish look so different from the adults that at one time they were thought to be entirely different species.

Classification and Scientific Name

The scientific name of the lizardfish family is Synodontidae. This is derived from a Greek term meaning ‘united’ or ‘grown-together teeth.’ There are more than 50 species divided across four genera.

Appearance

The lizardfish is characterized by a long, slightly cylindrical body, measuring up to 2 feet long, with a head resembling a lizard and a pointed snout. It has a mouth full of sharp, slender teeth, including on the tongue. Their splotched or mottled skin, which ranges between white, black, olive, brown, and even purple, helps them remain camouflaged against the sandy or muddy substrate.

Evolution and Origin

During the NORFANZ expedition on May 30, 2003, a deep-sea Lizardfish was captured by trawling at a depth of 325 to 497 meters on the Norfolk Ridge, located south of Norfolk Island.

The species is commonly found in shallow coastal areas such as saltwater creeks, rivers, bays, and sounds, as well as along open beaches with mud or sand substrates; it can also venture into deeper waters up to 180 meters along the continental shelf.

The deep-sea lizardfish (Bathysaurus ferox) resides at depths up to about 6,560 feet (2,000 meters), where it is among the deepest-living predatory fish. Equipped with razor-sharp fangs and possessing both male and female reproductive organs simultaneously, it boasts adaptations that enable its survival in the deep, lightless realms.

This voracious predator employs an ambush hunting strategy, burying itself in sand or mud and primarily preying on fish and small mobile invertebrates.

Distribution, Population, and Habitat

Most lizardfish are found in shallow tropical waters worldwide, including open seas, estuaries, and lagoons. They usually lie partly submerged in sandy substrate for protection against predators. Most species live in waters no more than 1,800 feet deep.

The one exception is the deep-sea lizardfish, which lives in the “midnight” or aphotic zone more than 3,000 feet deep. It is so deep that no sunlight can penetrate. Temperatures there hover around 40 degrees Fahrenheit.

Many species of lizardfish are found in the Gulf of Mexico and around Florida, including the well-known inshore lizardfish. Another common species, the brushtooth lizardfish, is located in the eastern Indian Ocean. There were reports that the brushtooth was introduced into the Red Sea and the Mediterranean, but this has not been confirmed.

According to the IUCN Red List of Threatened Species, the vast majority of lizardfish are considered to be of least concern. The rest are classified as data deficient (meaning there hasn’t been enough data gathered about the species to decide). More precise population data are not available. Unfortunately, many lizardfish die when they’re accidentally brought up as bycatch. Those that survive are usually thrown back into the water because they have little commercial value.

Predators and Prey

The lizardfish is a carnivorous animal. In some parts of the ocean, it is considered the apex predator.

What eats the lizardfish?

Lizardfish are generally preyed upon by larger types of fish. As mentioned previously, their primary means of defense is to sit at the bottom of the sea and blend in with the seafloor. If they sense they’ve been spotted, then the lizardfish will dart away and try to find a new hiding spot on the bottom.

What does the lizardfish eat?

The lizardfish preys mostly on smaller marine animals, including anchovies, shrimp, and squid. Some species are active hunters that go out looking for food. Some species will sit at the bottom of the sea and wait for prey to come by. They will then capture prey with their sharp teeth.

Reproduction and Lifespan

The spawning season for the lizardfish can take place at various times of the year, but it usually peaks in the summer. Females deposit their eggs in shallow waters, and males fertilize them.

While most species have defined sexes, deep-sea lizardfish are hermaphrodites, meaning they can produce both eggs and sperm simultaneously. This is an adaptation to their isolated deep-sea environment. They will have much greater reproductive success if they can mate with any other deep-sea lizardfish they come across.

The incubation period usually lasts just a few days. Juveniles receive no protection from their parents. After hatching, the fish will float freely in the water column, vulnerable to predators. A short time later, they descend to the bottom of the sea and begin feeding on prey.

Black spots near the organs are visible through the juveniles’ transparent, scaleless skin. The lifespan of the lizardfish is not well established, but it may range from seven to nine years.

Fishing and Cooking

Lizardfish are not generally fished commercially, but they are fished recreationally. Many of them are caught with a simple hook and line using natural bait such as shrimp or squid. The lizardfish can, in turn, be used as bait for larger fish. In the United States, the Gulf of Mexico and Florida are good fishing spots, especially for the inshore lizardfish.

The white, flaky edible meat supposedly tastes good when fried, baked, or grilled in various recipes, but it may take some effort to remove the bones from the flesh. Fortunately, the fish is not poisonous in any way and is entirely safe to eat. In Japan, lizardfish can be turned into a delicious paste. This type of paste is called cured surimi and can be used in various recipes. Kamaboko, for instance, is made by forming this pureed surimi paste into steamed loaves. It is often served with dipping sauce.