‘… very soon all the trout was gone except a scruddick, or fragment, of the tail.’
Williamson uses ‘scruddick’ to refer to a leftover trout tail. The OED defines ‘scuddick’ as an ‘extremely small coin or amount’ or ‘something very small’. Variants are skiddick or in Williamson’s case, scriddick and scrikkit:
‘Seaweed, black and brittle, lay below the wall with scriddicks of old rush-tops and sticks among white flowers of scruvy-grass.’
‘… the scrikkits of bones and scales…’
Now, say them all in swift succession six times over.
Source: Henry Williamson, Tarka the Otter: His joyful water-life and death in the two rivers, illus. C.F. Tunnicliffe (Harmondsworth: Puffin Books, 1976 (1927)), p. 65, 141 and 110