parr
n. countablen. a young salmon or trout that is still living in a river and has dark marks on its sides. It is a specific stage in the fish's life before it moves to the sea.
n. a young salmonid fish during the freshwater stage of its life cycle, specifically between the fry and smolt stages. Characterised by vertical dark bars, known as parr marks, along the flanks.
The small parr swam quickly between the river stones.
Fishermen are often reminded to release any parr they catch to ensure the salmon population can reach maturity.
During the parr stage, the juvenile salmon develops territorial behaviours and distinctive camouflage markings that protect it from predators in the shallow riverbed.
The plural form can be either 'parr' or 'parrs', though 'parr' is more common in technical biological contexts.