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River lamprey (Lampetra fluviatilis) is probably the most peculiar provincial fish in Finland, since it is not even a fish, at all, merely a cyclostome member of a jawless vertebrate superclass (Agnatha) that reaches as adult a body length of 25-35 cm and a weight of 40-65 grammes. Therefore, a lamprey has not got, at all, the scales that are typical to fish, nor has it jaws, moreover the paired limbic side fins also totally miss. Nevertheless, the lifecycle of lamprey is still typical to salmon fishes, a stage by stage cycle consisting of a river, a sea, and an upstream spawning migration stage, with an overall duration of 5-8 years. Having hatched from spawn a larval lamprey lives as blind ammocoete in the sludge at the river bottom for 4-5 years, and feeds on microorganisms as well as on faunal and floral litter that it strains. The lamprey larva experiences a thorough metamorphosis in the last year of the river stage of the lifecycle. Its eyes start to see, its mouth turns into a toothed suction disc typical to cyclostomes, its respiratory systems changes to one resembling that of shark fishes, and fins grow on its back. When the river life stage is completed, lampreys, now ready to migrate, are carried to the sea by flood waters in spring. At the sea stage, which lasts minimally for half a year and maximally two and a half years, lamprey is a predator which attacks mostly small fish. It sticks onto one side of its prey by its suction mouth, and starts eating its flesh. Fishermen may find attacked fish in their nets, for example herrings, with a hole on their side chewed by lamprey. Once the sea life stage is accomplished, fully developed lampreys totally cease feeding, and start approaching to rivers of Finland to migrate upstream from early fall to December and January. From the beginning of upstream migration for spawning to next year's May-June when spawning occurs, in other terms for a duration of 8-9 months lampreys live merely relying on the fat stored in their body. When spawning begins in early summer the male lamprey digs a small hole for the spawns at the bottom at a coarse sand spot that is freed from organic sludge by steady water stream, into which hole the female lays tens of thousands of spawns to be fertilised by the male. Fairly shortly after this, the lampreys that spawned die, just as usual also by other salmon-related fishes. Lamprey became an endangered species because of the acidification of river waters, even though unlike several other native fish species of Finland it tolerates the decreased light amount caused by floating humus and the decreased oxygen concentrations in the rivers. Through improved actions for conservation of waters and as a result of those, better water quality has helped lamprey stocks revive. Currently, up to some 2.5 million individuals, 100 tons of lamprey that is, are caught by fishers annually. At a global level, lamprey is commercially fished for at least in Australia, in the Baltic countries, in Canada, Siberia as well as in Finland. A good 90 per cent share of the amount caught in Finland comes from rivers that flow to the Gulf of Bothnia, and the following are famous lamprey rivers: Tornionjoki, Kemijoki, Simojoki, Iijoki, Pyhäjoki, and Kalajoki. In Southern Finland, lamprey stocks have strongly declined, but you still can catch this provincial "fish" of Satakunta to be enjoyed by the gourmets at Kokemäenjoki, and indeed sooty roasted lamprey is a much appreciated seasonal speciality on the autumn table of the bon-vivients in Satakunta. Lamprey gastronomy traditions are maintained with enthusiasm, especially in Nakkila, where lamprey is also a symbol animal in the local municipality coat of arms. Translated from Finnish to English by Volford Péter. Sources:
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