From autumn into early winter,some cool, fast-flowing British rivers play host to the annual spawning of our wild Atlantic salmon.

Having spent from two to four years feeding up at sea, some fish known as 'springers', enter river estuaries early in the year while others wait until autumn.

Initially using the earth's magnetic field and stellar guides to locate rivers, chemical scent and taste receptors then take over allowing fish to invariably remember and detect rivers of their birth.

Once in those rivers salmon do not feed again.

Colours darken, changing from silver to spotted pink hues and the lower jaws of cock salmon develop upturned hooks known as 'kypes' (pictured) with which they battle rivals when finally reaching the spawning grounds at the river's headwaters.

Leaping weirs and waterfalls,most salmon eventually reach their goal and spawning begins in shallow fast gravelly runs.

Large males usually win the attentions of hen salmon and the latter, using powerful sweeps of her tail excavates a shallow depression known as a 'redd' where, side by side, spawning takes place.

The act of spawning following their epic long journey exhausts the fish, most of which die but some, now called 'kelts', recover to become 'mended kelts' and once again make for the sea where they remain for a year or so before returning for a second spawning.

The so-called 'king of fish' certainly deserves his well won title.