Brook Trout Changing Colors Through the Seasons

[Dave_W]

We have all admired the beautiful colors seen on brook trout (and browns for that matter) during the autumn spawning season. It's part of the wild trout fishing aesthetic.

This effect seems most prominent on male fish. I've caught some brookies over the years at different times during the season and some of them really seem to brighten up in the fall. This is particularly true along the flanks and belly where reds, oranges, and black color tones can really become deeper or more widespread. Sometimes you see this in the dorsal and tail; less so on the pecs, pelvic, and ventral fins in my experience. It doesn't happen with every fish and does not always align with seasonal change. Some brookies remain washed out during the spawn and there are always some beautifully colored fish throughout the year.

So what have you seen? Have you caught a particular fish that was more colored up in fall?

 

[Dave_W]

I'm illustrating a long term project covering PA FF subjects and am currently working up a brook trout portrait showing this changed coloration.

So, here's our small stream male brookie in late February - March.

Stay tuned and watch him color up as the year progresses...

 

[gulfgreyhound]

WOW! looking forward to the rest of the portraits. GG

 

[Baron]

nice

 

[BradFromPotter]

A friend & I fishing a small stream in Tioga County several years ago in May caught several brook trout that were some of most colorful brook trout I have ever caught. We were back up this stream for the day & keep a few . Cooked right along the stream. They were filled with very small bright orange crayfish. I always wondered if that had anything to do with their colors being so bright.

 

[wildtrout2]

BradFromPotter wrote: We were back up this stream for the day & keep a few . Cooked right along the stream. They were filled with very small bright orange crayfish. I always wondered if that had anything to do with their colors being so bright.

I believe it would at least contribute to their brilliant colors. I've read that trout that have crustaceans as a part of their regular diet will have pink flesh. I've seen this to be true with wild browns as well.

 

[dc410]

Very nice, Dave. I’m looking forward to the rest of your drawings as well.

I know of a few very small “blueliners” in the central PA area that always seem to hold beautifully colored brook trout. I was never sure whether is was more genetics or diet or something else that contributed the most to their color.

 

[troutbert]

I've caught brookies in early May that had vivid coloration similar to spawning colors.

Most of these brookies were caught way up on small streams. The brookies further downstream tend to be less colorful.

I've noticed this pattern sometimes during a day's fishing. If you start near the mouth of a stream and fish way up until the stream gets quite small, the brookies often get brighter colored as you proceed upstream.

I don't know the reason.

 

[lycoflyfisher]

I think that diet in particular crustaceans such as crayfish really drove the bright red pigments. That said so does light, I have yet to catch or witness one during my electrofishing days that was dark, almost black in an open canopy or meadow type habitat.

 

[HopBack]

I have fish a unique stream from time to time where all male fish caught exhibit year round bright red bellies and all females are dark with purple fins. These fish were both caught in April. I believe this to be the case because of the abundance of crayfish in the stream, maybe not something that is very common in most brookie streams.


Male

Female

 

[Dave_W]

Neat.

As pointed out, a crustacean diet has been claimed to produce more vivid colors in trout. This is sometimes thought to be a result of the ingredient chitin in the critters' exoskeletons.

Your discovery seems to support this. I think the orange color of the crayfish was probably a result of their decomposition in the fish's gut rather than being orange to begin with - think boiled lobsters or crayfish. Dead scuds turn orange too. Is this connected to chitin?

More broadly, I don't think brookies in mountain streams tend to have a lot of crustaceans in their diet when compared to trout in valley or limestone streams where crayfish and scuds are numerous - sometimes very much so - and are eaten by a lot of trout (and smallmouth bass). There are obviously some interesting exceptions, such as Hopback's special stream alluded to above where the presence of cray's may play a role (Hop: that's a neat purple fin on the lower fish).

Brookies in Big Spring eat a lot of scuds and they're slightly less colorful than freestone STs in my experience - some are really pale with only the bright red fins standing out. They do color up during the spawn however with their backs developing a striking slate/green/beige tone that is really noticeable and the males get the orange flanks.

Interesting stuff.

 

[Dave_W]

troutbert wrote:
I've caught brookies in early May that had vivid coloration similar to spawning colors.

Most of these brookies were caught way up on small streams. The brookies further downstream tend to be less colorful.

I've noticed this pattern sometimes during a day's fishing. If you start near the mouth of a stream and fish way up until the stream gets quite small, the brookies often get brighter colored as you proceed upstream.

I don't know the reason.

Fascinating.
I have never noticed this tendency but will watch out for it more. It seems plausible in a sort of "micro-watershed" effect. If one looks at salter populations the fish "downstream" near or within tidal areas really seem to wash out with white spots and exhibit a silver sheen. Perhaps the downstream brookies tend to move more, or are under less tree cover, and hence washed out(?).
Hhmmm...

 

[Bamboozle]

Two non-seasonal things I've observed that while understandable and not so startling, seem to be more dramatic with brook trout I’ve caught and that is coloration that differs because of the water color or the bottom color.

A REALLY long time ago while in East Stroudsburg for a big TU pow-wow on NJ stocking Pacific salmon in the Delaware (remember that?), I went searching for a Class A that was on a PFBC map and the VERY short Class A list that was out there at the time.

Well, I found the creek (now off the Class A List and posted) which appeared black from the tannins in the water and the black stream bottom. I managed to catch a very cooperative rising brookie that was about 5” long. This brookie was as black as the stream but with brilliant red spots. I went back to that stream once again and caught another, just as black.

I also fish a couple of Class A’s in Carbon County with very light colored bottoms, which I imagine are sandstone or some other sedimentary rock. The brookies I catch at those streams look almost like brown trout with almost no color on their flanks and few but VIVID spots.

 

[Dave_W]

Bamboozle wrote:


A REALLY long time ago while in East Stroudsburg for a big TU pow-wow on NJ stocking Pacific salmon in the Delaware (remember that?),

Yeah, that didn't turn out very well, or the effort with steelhead. I don't recall the year that was attempted. Early 80s? PA dropped Chinooks from Erie in the mid 90s. This would make a good thread.

Brookies from tannin stained streams do often appear very dark. The STs I've seen in New England often exhibit this trend.

 

[Dave_W]

So here's our lil guy by summertime.

He's starting to color up, and maybe moving upstream at the same time?

 

[Bamboozle]

Dave_W wrote:

Bamboozle wrote:


A REALLY long time ago while in East Stroudsburg for a big TU pow-wow on NJ stocking Pacific salmon in the Delaware (remember that?),

Yeah, that didn't turn out very well, or the effort with steelhead. I don't recall the year that was attempted. Early 80s? PA dropped Chinooks from Erie in the mid 90s. This would make a good thread.

I may still have the feasibility study laying around.

PA, NY and just about everybody but NJ was against it for a lot of good reasons. I'm glad it never happened.

Beautiful artwork BTW!!

 

[Dave_W]

As the summer months transition into fall, our lil guy has colored up to meet the ladies.

Typically, the most striking changes are in along the lower flanks with deeper oranges and reds coming out and spreading upward, often edged with yellow. Black tones across the chin and belly may also darken; dorsal and tail can also sometimes reveal striking yellow, orange, and reddish brown colors as well.

So here he is in early spring, summer, and autumn.

 

[Baron]

Very instructive Dave. Great work.

 

[Bamboozle]

Stocked... ;-)

 

[Dave_W]

Bamboozle wrote:
Stocked... ;-)

Well played Sir!
int: