Mark’s Stonefly Black is an effective fly pattern designed to imitate the stonefly nymph, a crucial food source for trout and other freshwater fish. This pattern features a robust, dark silhouette that ensures visibility in various water conditions, making it particularly useful in both clear and slightly murky waters. Its realistic design includes prominent legs and a segmented body that enhance its natural appearance. Anglers should use this fly in a nymphing setup, allowing it to drift along the riverbed where stoneflies typically reside.