Size Matters: A Review of Live Feeds Used in the Culture of Marine Ornamental Fish

The marine ornamental fish trade generates over USD1.5 billion annually and continues to increase. However, only 35 fish species are thought to be commercially produced for sale currently, a small proportion of the 1800 species recorded within this trade. The limiting factor in marine ornamental fish production is the requirement for appropriately sized live food as a first feed. This is due to the small gape size of many fish species of interest to the trade. The need for suitable live feeds has therefore caused a bottleneck in the production of marine ornamental fish species and developments are needed to allow an expansion of this culture industry. This review considers the current usage of live feeds, including Artemia, rotifers, copepods, and ciliates and discusses the advantages and disadvantages of each when used to culture marine ornamental fish. Whilst success has been seen with these feeds for several commercially important marine ornamental fish species, the current lack of appropriately sized live feed items for higher value species, such as dwarf angelfish, remains a problem for the industry. Live feeds currently used often exceed the gape size of such species at the onset of exogenous feeding, resulting in limited commercial success. Future developments focussing on novel and existing live feeds used within the industry for these valuable species are explored. These developments will enable aquaculture, rather than the exploitation of wild populations, to meet future demand and will encourage progress in the aquaculture of marine ornamental fishes.