At first glance, the LamPrey looks remarkably like the Articulated Leech. Both are big, dark and articulated with red gill filaments, but the subtle differences can make a big difference on how the fly performs.
Most often, the Articulated Leech is fished in heavy, moving water where you want to get a fly down quick to swim through the deeper runs and fast moving riffles. In contrast, the LamPrey is an ideal Stillwater pattern for working near the surface. It's generally tied with little to no weight with a deer-hair head and collar for added buoyancy. Fished on a floating line, the LamPrey can be stripped in shallow water to create a bubbly surface disturbance and wake as the bulky head plows through the water. The large, dark and lively profile moving across the surface draws explosive strikes from pike and the largest of trout.
When fished on a sinking line, the buoyant properties add yet another dimension that is described well in Barry Reynolds book Pike on the Fly. For working a larger area of the water column, Barry suggests casting the weighted line, then waiting as it sinks to the proper depth. Even though the line is sinking, the buoyant fly will remain on the surface until you begin to strip aggressively, at which time the fly will be towed, diving into deeper water. 3 or 4 big strips will take it deep, but if there's a pause in the retrieve, the fly will again begin to wiggle its way toward the surface until it's again stripped to deeper water. So not only does this method cover water from the point of cast to the angler, the fly moves up and down in the water column. Fish dictate where and how to present flies, but at least with the LamPrey, we've got a few options with a single pattern.
