Killed a small trout yesterday for the table -this morning's breakfast in fact. Below is what was dissected from the stomach. It came from a high gradient stretch of mountain stream at about 6500ft elevation.
Stomach contents tell me more than anything else about how trout are actually spending their time. I try to pump at least one or two fish every outing and carry tubes of different sizes for different size trout. But nothing beats actual dissection for the full story. Since I frequent small unsung streams mostly there is little danger in taking some fish for the table.
What always strikes me upon viewing trout stomachs is how good trout are at discerning food from flotsam. Beyond the occasional oddball tidbits, trout stomachs tend to contain almost entirely food items many of which are truly minute and seemingly well camouflaged. Trout are good at identifying “food” from “not food”.
This 8" female brown was thin following winter as snow had recently left its stretch. The water is low due to lack of precipitation but the high gradient still offers good current speed for drift feeding. The stomach contents show that she had been feeding eclectically. It is likely that the low water has consolidated living space and competition amongst inverts which may have put some into the drift. It is also likely that this fish was gleaning larvae from the substrate -possibly evidenced by both cased caddis and esp, several Heptageniids. The fish took a #20 Baetis nymph fished off a #16 Baetis dry.
This little brown had a rather large bait hook fully in its stomach. The hook was well in process of dissolving, which can happen, if the fish doesn’t die from hook wound trauma first.
The Brachycentrus cases all had larvae within, meaning the trout chose live critters versus the empty cases one can often find on rock tops along with occupied ones. Either the trout took them from the drift, or gleaned them after seeing the movement of the feeding larvae. These may be occidentalis (spring emergence) or americanus (summer emergence). They had not begun pupating yet, which I’d expect is underway or imminent in occidentalis by this date. Other suggestions?
The interesting thing about these midge pupae is that they were the only critters that floated in the dish of water I dissected into. I wonder if this buoyancy is involved in getting those pupae to the surface as has been suggested for caddis. I can’t imagine how such tiny pupae could get to the surface in such cold turbulent water otherwise.
I hear my tying bench calling ...