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Lancetfish

life science Maturity 5-7 Next article →

The lancetfish is a large predator that lives in the deep parts of the ocean.

Lancetfish smithsonian
Lancetfish smithsonian

Its scientific name, Alepisaurus, means "scaleless lizard" in Greek. These fish are found in almost all oceans except for the cold polar seas. Some have even been seen as far north as Greenland. They are often caught by accident by ships fishing for tuna. Scientists call this "bycatch," which means they were not the main target. Because they are so large and eat so much, they are very important to study.

Lancetfish smithsonian
Lancetfish smithsonian

To hunt, the lancetfish uses a very specific way of working.

It has a slender, flat body and a silvery color to hide from prey. It floats in the water and uses large eyes to scan for food. When it finds something, it uses its forked tail for a fast burst of speed. A very tall fin on its back helps it stay steady while it moves. The fish then uses a wide mouth and large, fang-like teeth to grab its meal. Their stomachs can stretch to hold many different things.

There are two main types of lancetfish living today.

One is the long-snouted lancetfish, known as Alepisaurus ferox. The other is the short-snouted lancetfish, or Alepisaurus brevirostris. Scientists named the long-snouted version in 1833. The short-snouted version was named by Gibbs in 1960. There is also a fossil species called Alepisaurus paronai from Italy. This fossil comes from the Middle Miocene time period. These different species live in different parts of the world's oceans.

Lancetfish live at many different depths in the sea.

PC12 sta 16 Alepisaurus ferox DSC 0012
PC12 sta 16 Alepisaurus ferox DSC 0012

Most stay between 100 and 2,000 meters deep. They eat many things like fish, squid, octopods, and even crustaceans. Because they digest food very slowly, their stomachs act like a collection of clues. Researchers look inside them to learn about other deep-sea life. Some new types of fish were even discovered because they were found inside a lancetfish stomach. However, scientists have also found plastic refuse inside some of them. This shows how trash from the surface can reach the deep ocean.

PC12 sta 16 Alepisaurus ferox DSC 0012
PC12 sta 16 Alepisaurus ferox DSC 0012

Learning about lancetfish helps us understand the whole ocean.

Lancetfish smithsonian
Lancetfish smithsonian

They are like moving maps of the deep sea. By looking at what they eat, we can see what else is living nearby. Even though they are mostly solitary, they connect different parts of the water. For example, they might travel to the Bering Sea to find food. In 2023, many of them washed up on beaches in Oregon. People there were asked to take photos to help experts track them. This helps us keep a close eye on our changing oceans.

Lancetfish smithsonian
Lancetfish smithsonian
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🖼️ Images & Media (4)
File:Lancetfish Alepisaurus ferox Okeanos 2017 (cropped).jpg
Lancetfish Alepisaurus ferox Okeanos 2017...
File:Lancetfish smithsonian.JPG
Lancetfish smithsonian.JPG
File:Alepisaurus ferox PC14-04 sta16 IMG 6741.jpg
Alepisaurus ferox PC14-04 sta16 IMG 6741.jpg
File:PC12 sta 16 Alepisaurus ferox DSC 0012.jpg
PC12 sta 16 Alepisaurus ferox DSC 0012.jpg
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