<Tr> <Td> Asian side </Td> <Td> Masu salmon </Td> <Td> 79 cm </Td> <Td> 10.0 kg </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Biwa salmon </Td> <Td> 44 cm </Td> <Td> 1.3 kg </Td> <Td> </Td> <Td> </Td> </Tr> <P> The life cycle of an anadromous salmon begins and, if it survives the full course of its natural life, usually ends in a gravel bed in the upper reaches of a stream or river . These are the salmon spawning grounds where salmon eggs are deposited, for safety, in the gravel . The salmon spawning grounds are also the salmon nurseries, providing a more protected environment than the ocean usually offers . After 2 to 6 months the eggs hatch into tiny larvae called sac fry or alevin . The alevin have a sac containing the remainder of the yolk, and they stay hidden in the gravel while they feed on the yolk . When the yolk has gone they must find food for themselves, so they leave the protection of the gravel and start feeding on plankton . At this point the baby salmon are called fry . At the end of the summer the fry develop into juvenile fish called parr . Parr feed on small invertebrates and are camouflaged with a pattern of spots and vertical bars . They remain in this stage for up to three years . </P> <P> As they approach the time when they are ready to migrate out to the sea the parr lose their camouflage bars and undergo a process of physiological changes which allows them to survive the shift from freshwater to saltwater . At this point salmon are called smolt . Smolt spend time in the brackish waters of the river estuary while their body chemistry adjusts their osmoregulation to cope with the higher salt levels they will encounter in the ocean . Smolt also grow the silvery scales which visually confuse ocean predators . When they have matured sufficiently in late spring, and are about 15 to 20 centimetres long, the smolt swim out of the rivers and into the sea . There they spend their first year as a post-smolt . Post-smolt form schools with other post-smolt, and set off to find deep - sea feeding grounds . They then spend up to four more years as adult ocean salmon while their full swimming ability and reproductive capacity develop . </P>

When do salmon go up river to spawn
find me the text answering this question