Lampetra

Lampetra is a genus of jawless fish belonging to the family Petromyzontidae, commonly known as brook lampreys. These are small, eel-like vertebrates that are native to freshwater environments in the Northern Hemisphere. Unlike their parasitic relatives, lampetrids are non-parasitic as adults. They are characterized by their primitive features, including a cartilaginous skeleton, a lack of paired fins, and a circular, jawless mouth equipped with horny teeth. Adult brook lampreys typically feed on algae and detritus, which they filter from the water or scrape from surfaces using their mouths. Their life cycle involves a prolonged larval stage, known as an ammocoete, which lives buried in the sediment of streams and rivers. The ammocoetes are filter feeders. After several years in this larval form, they undergo metamorphosis into the adult stage. Brook lampreys are an important part of their freshwater ecosystems, serving as a food source for other animals and playing a role in nutrient cycling. Several species are recognized within the genus Lampetra, with varying distributions across Europe, Asia, and North America. Conservation concerns exist for some species due to habitat degradation and pollution.