**Sea Lamprey**
**Definition**
The sea lamprey (Petromyzon marinus) is a jawless parasitic fish native to the North Atlantic Ocean and adjacent freshwater systems. It is known for its distinctive toothed, funnel-like sucking mouth used to attach to and feed on other fish.
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**Sea Lamprey**
The sea lamprey (Petromyzon marinus) is a primitive, eel-like fish belonging to the class Agnatha, characterized by its lack of jaws and paired fins. It inhabits coastal and freshwater environments in the North Atlantic region. Adult sea lampreys are parasitic, attaching to host fish with their suction-cup mouth lined with sharp keratinized teeth. They feed by rasping through the host’s skin to consume blood and bodily fluids, often causing significant harm or death to the host.
### Physical Description
Sea lampreys can grow up to 120 cm (47 inches) in length. Their elongated, cylindrical bodies are scaleless and covered with smooth, slimy skin. The mouth is circular and equipped with multiple rows of sharp teeth, surrounding a rasping tongue used to penetrate the flesh of host fish.
### Life Cycle
The sea lamprey has a complex life cycle involving both freshwater and marine stages. Adults migrate from the ocean into freshwater rivers and streams to spawn. After hatching, larvae (ammocoetes) burrow into sediment and filter-feed for several years before metamorphosing into parasitic adults. Following the parasitic phase, adults return to freshwater to reproduce and then die.
### Ecological Impact
In their native range, sea lampreys play a role in aquatic ecosystems, but they are considered invasive in the Great Lakes of North America. Introduced in the early 20th century, they have caused severe declines in native fish populations due to their parasitic feeding habits. Control measures include barriers, chemical lampricides, and trapping to reduce their numbers.
### Importance and Management
Sea lampreys are studied for their unique evolutionary position and biological adaptations. Management efforts focus on balancing their ecological role with the protection of economically important fish species, particularly in areas where they are invasive.
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**Meta Description**
The sea lamprey is a jawless parasitic fish native to the North Atlantic, known for its suction-cup mouth and impact on fish populations. It has a complex life cycle involving both freshwater and marine environments.