10 20 40 60 cm
mittakaava > 60 cm
© Copyright: Images:
Wilhelm von Wright: Pohjolan kalat. All rights reserved.
- Family: Lampreys – Petromyzonidae
- Similar species: river lamprey
- Size: 55–95 cm, can exceed 2 kg.
- Appearance: Like other lampreys, the sea lamprey belongs to the class known as jawless fishes, making it quite distinct from other fish. It has no paired fins, no lower jaw, and the mouth is surrounded by a round, sucker-like disc. The sea lamprey has more teeth than the more familiar river lamprey and these are arranged in several rings. The best way to distinguish the two is through size: the sea lampreys that have found their way into Finnish waters have been over 50 cm in length, whereas the common river lamprey rarely attains more than 40 cm.
- Colouring: The colour of the back is another guide to identification: the sea lamprey’s back is dark with clear mottling, while the river lamprey has no such markings.
- Reproduction: Like its cousin, the sea lamprey ascends rivers to spawn. The larvae may spend as long as 5–8 years in the river followed by some three years of growth in the sea. Not thought to reproduce in Finnish rivers, although most individuals encountered have been sexually mature and present in estuaries, presumably trying to find their native river.
- Food: Attaches itself to the side of a fish, rasping away the skin and eating the flesh beneath.
- Distribution and habitat: The sea lamprey is a North Atlantic species and is found only occasionally in the Baltic.