Grayling

Not exactly, but it is a close relative. The grayling belongs to the salmon family, Salmonidae, in its own subfamily, the Thymallinae, alongside the trout, salmon, and char subfamilies. It shares the family's hallmarks, including a small fleshy adipose fin on the back near the tail, spawning over gravel, and a need for cold, clean, oxygen-rich water. What sets it apart is the huge sail-like dorsal fin, a small mouth with weak teeth, larger scales, a herring-like silvery sheen, and spring rather than autumn spawning. Anglers often group grayling with trout as "game fish" and fish for both with a fly rod, but the two are different enough that grayling are given their own subfamily.

The name is old and affectionate, used by British fly-anglers, and it reflects both the fish's appearance and its manner. A grayling in the water is elegant and understated, silver-grey with a violet sheen and that tall, delicately marked fin, and it feeds in a quiet, deliberate way, holding station in the current and tipping up to intercept nymphs. It is also traditionally regarded as a slightly capricious, hard-to-tempt fish that rewards a careful, well-presented cast. The pairing with the trout as the "gentleman" of the stream is part of the same angling folklore.

In the middle reaches, in what is sometimes called the grayling zone, downstream of the fast, tumbling headwater trout water and upstream of the slow, warm, silty lowland stretches where roach, bream, and chub take over. Grayling favour long, even glides and runs of moderate depth over clean gravel, with a steady current, and they often hold in loose shoals on the river bed, unlike the more solitary and territorial brown trout. They need well-oxygenated water and a gravel bed clean enough to spawn in, so they are absent from rivers that have been dredged, silted, over-abstracted, or polluted.

Globally it is listed as Least Concern because it remains widespread and locally common across northern and central Europe, but at the river-by-river scale the picture is worse. Grayling have been lost from or greatly reduced in many rivers in England, France, Germany, and elsewhere, through a combination of habitat degradation, chiefly siltation of spawning gravels, low summer flows from water abstraction, barriers such as weirs that block movement, pollution incidents, and, in some places, heavy predation by cormorants on rivers where the fish have nowhere to hide. Restoration work focuses on cleaning and re-opening gravel spawning reaches and improving flows.