Fact Zap

Lamprey Fish Facts

Lamprey fish are one of the oldest surviving animals on Earth. They cannot bite or chew. Their mouth is like a tube. They are jawless fish who can only suck on food. Jawless fish are the earliest vertebrates.

Lamprey vampire fish illustration by Fact-zap

Lamprey fish look a lot like eels. Their jawless mouth is circular and always open. It is like an open tube, tongue in the center surrounded by circular discs of sharp teeth.
Without jaws, they cannot open and close their mouth or chew food. So, how do they eat ..? Their drill holes and suck in food. It is digested straight away in the intestine as they have no stomach.

Living fossils

Lampreys are one of the oldest surviving fish. They have been around for 360 million years. They were thriving 130 million years before dinosaurs first appeared on Earth. Humans came much later. But in a short span of time, humans evolved from apes to space explorers. Lampreys have remained largely unchanged. They are similar to their prehistoric fossils, except for a few changes. They are called LIVING FOSSILS !

Vampire Lampreys

Half of the Lamprey types living today feed on planktons in water. They are filter feeders, leading a quiet life. But few lamprey types are (in)famously called vampire fish. They drill holes in the body of bigger fish, hook their razor sharp teeth and suck blood. They use their tongue like a suction cup. While adult lampreys use this vampire like method, young larvae feed only on planktons.

Why Lampreys suck blood

Primitive Lampreys were filtering planktons from water and feeding on them. During Jurassic period, it is likely they evolved to bigger sizes. They developed stronger teeth and scraped off scales and flesh of big fish. Lamprey types that were still scraping algae and planktons were weaker and their eggs and larvae were also weak. Only fish that started scraping flesh grew in size. Their eggs and larvae were also stronger. They had higher chances of survival. Their mouth evolved to adapt to this feeding method.
Lamprey teeth are made of keratin, same as human nails and animal hooves. It is arranged in circular discs, with smaller discs on the inside and larger discs on the outside. Each disc has rows of small, razor sharp teeth.

Where do they live

Freshwater Lampreys live in rivers and land locked lakes their whole life. Saltwater Lampreys are born in freshwater streams that run into seas. They live there for many years, transform by metamorphosis (like butterflies) in to adult lampreys and swim back to sea. When they are old enough, they move back to the stream to lay eggs.
Lampreys do not like warm waters. They cannot live in tropical seas and oceans. They are found in the Atlantic and Pacific oceans. They are common in North American coast, South western areas of Europe, Baltic, Adriatic and Mediterranean seas.

Are they dangerous

Fleas suck blood from animals, but are not big or strong enough to kill the host animal. Lampreys too cannot kill big fish. They leave open wounds which risk infections.

Endangered status

Lampreys make tasty food. They are a delicacy in Scandinavia, continental Europe and East Asia. Lamprey pies were served to English royals in medieval times. But habitat loss and pollution have made them endangered in many parts of Europe. Conservation efforts have led to removal of Lampreys from food menus. Coronation of King Charles III saw a traditional pork pie with lamprey decorations made of sugar pastry.
In North America, Lampreys have a different story. Sea lampreys in the Great lakes in North America have increased in hoardes. They have become an invasive species, meaning a species whose population has invaded the area threatening the local ecosystem. Efforts are on to bring their numbers under control.