Study of fish assemblages in Ecklonia radiata dominated rock reefs in subtropical eastern Australia and dietary analyses of three species of generalist predators of the family Labridae

Spatial and temporal patterns of fish assemblages were examined for Ecklonia radiata dominated rocky reefs in subtropical eastern Australia. The wrasses Notolabrus gymnogenis, Ophthalmolepis lineolata and Pseudolabrus guentheri were the most abundant carnivorous species. Subsequent dietary analyses using DNA metabarcoding identified 70 different Operational Taxonomic Units in the gut contents of these species. The results provide novel information on prey diversity and suggest that these species occupy a high trophic level in the food web of kelp-dominated reef habitats in the region. The study also confirmed DNA metabarcoding as a powerful technique for dietary analysis of generalist predatory fish.