Sea lamprey
The sea lamprey is a jawless, eel-like fish known for its parasitic behavior, often referred to as the "vampire fish" due to its suction mouth and sharp teeth that allow it to attach to other fish and consume their blood and bodily fluids. This species can inhabit both salt and freshwater environments, with notable populations in the Great Lakes, Mediterranean Sea, and along the Atlantic coasts of Europe and the United States. Sea lampreys can reach lengths of up to two feet in freshwater and four feet in saltwater, displaying distinctive blue-gray to olive-brown skin with cream or yellowish undersides and black mottled patterns.
As an anadromous species, adults migrate upstream to spawn in freshwater, while larvae, known as ammocoetes, live in the sediment for five to seven years before metamorphosing into their adult form. This transformation allows them to move back into the sea or other freshwater bodies. The sea lamprey poses a significant threat to local fish populations, as their parasitic feeding can lead to the host's illness and death. With a lifespan of up to 11 years, these creatures play a complex role in their ecosystems, where their impact on fish populations is a topic of ongoing concern and research.
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Sea lamprey
The sea lamprey is a common, eel-like, jawless fish that may live in salt or freshwater. With its suction mouth and sharp teeth, it attaches to the sides of fish and sucks their blood and fluids. It is sometimes called the "vampire fish."
Kingdom: Animalia
Phylum: Chordata
Class: Hyperoartia
Order: Petromyzontiformes
Family: Petromyzontidae
Genus: Petromyzon
Species: Marinus
A serious threat to the health and life of many fish in the Great Lakes, Mediterranean Sea, and those along the Atlantic coasts of Europe and the United States is the sea lamprey. This eel-like fish swims through the water at depths of up to 500 fathoms. A fathom is six feet (180 centimeters), so the lamprey may be found nearly 3,000 feet (900 meters) underwater. At this depth, the lamprey looks for fish to eat. It may not have jaws to bite fish, but it has a suction disk around its mouth with sharp teeth for rasping, or roughly scraping, a hole into the side of the fish. It sucks the fish's blood and bodily fluids. This is called parasitism, and the lamprey is a parasite, or an animal that lives on or inside another animal called a host. The host may become sick and eventually die.
A sea lamprey may be up to two feet (60 centimeters) long in landlocked freshwater, while one in saltwater may reach four feet (just over one meter) long and have a maximum weight of 4 3/4 pounds (2.2 kilograms). The sea lamprey has blue-gray to olive-brown skin on its back, sides, and fins, while it has cream or yellow-white skin on its underside. Black mottled markings cover most of its body. Along the lower half of the back of the eel-like body are two rounded, hump-like dorsal fins. The fin around the tapered tail is small.
Adults move upstream to spawn, or to lay and fertilize their eggs. Even those sea lampreys in saltwater swim upstream to freshwater. They are anadromous, which means they live as adults in saltwater and spawn in freshwater. The larvae, or young, are called ammocoetes or prides and do not look like adults. They burrow into the mud and live on particles in the water for five to seven years. At this time, they metamorphose, or change in body shape, and look like adults. They then swim to the sea or other bodies of freshwater.
The life span of the sea lamprey is up to 11 years.
Bibliography
"Petromyzon Marinus Linnaeus, 1758." Fish Base, fishbase.net.br/summary/Petromyzon-marinus.html. Accessed 1 May 2024.
"What Is a Sea Lamprey?" National Oceanic and Atmospheric Administration, oceanservice.noaa.gov/facts/sea-lamprey.html. Accessed 1 May 2024.