Q.
Sorry, not an inside tip on where
to find the big one.
Ladyfisher suggested that I contact you with
my question on brown trout spots. Attached
are a couple of photos that I hope don’t gum
up the works too much with download time.
I’m curious to know why some browns are more
spotty than others. Nature, nurture, age, a
combination of all? Which factors are more
important? The fish with the most spots came
from healthier water, by the way.
Thanks for your time.
A.
I’m probably not going to give you satisfactory
answers to your questions, but rather give you
some quotes from some expert’s writing in a
couple of books.
Dr. Bob Behnke in his book Trout and Salmon
of North America says, “…but color varies
among individuals from pale, silvery gray tinted
with shades of greenish blue, to deep golden yellow,
dark red, or orange that suffuses the lower half
of the body. Because of the mixed and diverse
ancestry of brown trout introduced into North
America, nearly the complete spectrum of spotting
and coloration in brown trout world wide can be
found among American brown trout populations.”
This quotation would seem to infer that genetics
plays a significant role in the development of spots.
Robert A. Bachman, author of the chapter on
brown trout in the book Trout, has this to
say about the subject: “The almost limitless
variations of color, shape, spot patterns,
fin markingséhave been the source of frustration,
confusion, acrimonious debate and resignation
for more than a hundred years.” He then goes
on to describe the basic coloration and variations
of brown trout and then says, “Although all forms
and races of brown trout exhibit some or all of
the above characteristics in the juvenile, or
parr stages, much of the coloration disappears
or is masked by a silvery coloration when the
trout lives in deep, clear lakes of when it
smoltifies… Further, the black and red
spots on some forms are more irregularly shaped
than on other forms, and when the coloration is
masked by a proliferation of guanophores…,
markings and coloration are poor, if not useless,
means of identification.” The author goes on to
discuss the use of spot characteristics for use
in identification and also discusses the fact
that the brown trout is the only trout that has
red or orange spots on the margin of the adipose
fin; this, however, is often lacking in
hatchery-reared browns unless they have been
fed a special diet or they survive long enough
in the wild to eat enough natural food to develop
this distinctive color characteristic. I suspect
that most of us have noticed that lake browns are
lighter in color than stream-bred browns; this
would lend credence the “nature” aspect of your
question, and the food aspect would support “nurture.”
So there you have it - nature and nurture both
look like they can play a part, and you can’t
leave out genetics.
Hope this sheds some light on the subject.
~ Bert
If you have a question, please feel free to contact me.
~ C. E. (Bert) Cushing, aka Streamdoctor
105 W. Cherokee Dr.
Estes Park, CO 80517
Phone: 970-577-1584
Email: streamdoctor@aol.com
The ‘Stream Doctor’ is a retired professional stream ecologist and
author, now living in the West and spending way too much time
fly-fishing. You are invited to submit questions relating to
anything stream related directly to him for use in this Q & A Feature
at streamdoctor@aol.com.
Originally published June 20, 2005 on Fly Anglers Online by Bert.