Acroneuria lycorias (Golden Stone) Stonefly Nymph Pictures

Here's a good example of an Acroneurinae species other than A. abnormis that can have a dark body. The presence of anal gills and a thick occiptal bar impinged by a black spot in the middle point to lycorias. The picture is dark and the angle gives the head the flat based triangle look of the Perlinae, but if you enlarge the photo and look closely, the pale occipital bar at the back of the head is located where the ridge should be, precluding that subfamily.