DNA metabarcoding confirms primary targets and breadth of diet for coral reef butterflyfishes

Understanding species-specific resource requirements is paramount in managing and protecting biodiversity in a world where environmental quality is in decline. Dietary data can inform predator–prey relationships and how changes in prey availability impact different species. However, for many coral reef fishes, prey and predatory events can be difficult to observe and identify, both in situ and within examined stomach samples. Here we applied DNA metabarcoding of stomach content samples for eleven Red Sea butterflyfish species to identify the diversity of dietary components that these primarily benthic feeding fish consume across coral reefs. Detections based on 18S and COI sequences from partially digested stomach contents significantly increased the resolution and diversity of the known diet for this group of fish, which included cryptic prey that are difficult to visually document due to soft parts or morphological ambiguity. In addition to scleractinian corals and other Cnidaria, the...