At a recent meeting of the Scotch Fisheries Improvement Association,
held at Edinburgh, Mr Harvie-Brown communicated some notes on
trout-life, which the Association considered of so much scientific
interest, that it was resolved to engross them in the minutes. The
notes are as follow:
‘The subject of coloration of flesh of trout is a much more intricate
one than at first appears. I know of trout holding largely developed
spawn in June and July in a loch in Sutherland, whose flesh is not pink
only, but bright red like a salmon’s, and yet are not fit to be eaten.
I know, also, in a limestone burn the very finest trout, which on the
table are perfectly white in the flesh, whatever size they grow to;
but in another limestone burn from the same sources, or nearly so, the
trout are quite different in appearance externally, but equally white
in flesh and equally delicious for eating.
‘I put a quarter-pound trout, along with others, into a previously
barren loch. In two years some of these trout attained to four and
a quarter pound-weight, developed huge fins and square or rounded
tails, lost all spots, took on a coat of dark slime, grew huge teeth,
and became _feroces_ in that short time. The common burn trout, taken
from a very high rocky burn up in the hills, in two years became
indistinguishable from _Salmo ferox_. The first year they grew to
about a pound, or a pound and a half, took on a bright silvery sheen
of scales, were deep and high shouldered, lusty and powerful, more
resembling Loch Leven trout than any others. This was when their
feeding and condition were at their best; but as food decreased,
and the trout rapidly increased in number, spawning in innumerable
quantities, and with no enemies, the larger fish began to prey on the
smaller, grew big teeth, swam deep, and lost colour, grew large fins
and a big head, and became _Salmo ferox_ so called. In two years more
the food-supply became exhausted; and now the chain of lochs holds
nothing but huge, lanky, kelty-looking fish and swarms of diminutive
“black nebs,” neither of the sorts deserving of the angler’s notice.
The first year they were splendid fish—rich and fat. Now they are dry
and tasteless.’