25
Feeds for Ornamental Hatcheries
By Eric C. Henry PhD, Research Scientist, Reed Mariculture Inc. Keeping a freshwater or marine aquarium is an increasingly popular hobby, and the demand for ornamental fish and invertebrates continues to grow. Widespread concern about destructive fishing methods and depletion of wild stocks of popular ornamentals is stimulating efforts to bring many more species into captive propagation. Captive -bred ornamentals offer additional advantages because they are adapted to conditions in captivity, and they pose significantly less risk of introducing pathogens and other harmful organisms. Hatcheries are therefore becoming increasingly important in the supply chain of ornamental species.
Several recent reviews have described captive breeding techniques and the many challenges still to be overcome. One review noted that more than 90% of freshwater ornamental species are currently farmed, whereas most marine ornamentals are still wild-caught. Several factors account for this difference: Freshwater aquarium keeping has a much longer history; seawater chemistry is more complex, making aquarium maintenance more difficult; marine ornamental species tend to be more difficult to collect; the variety of marine ornamental species is much greater; marine ornamentals often have larval stages that are challenging to keep in
culture; marine ornamentals often have highly specialized feed requirements. Moreover, hatcheries producing marine ornamental species have feed requirements that can be very challenging compared to those of hatcheries producing food finfish or shellfish. Ornamental species encompass a much greater diversity of not only finfish and shellfish, but also corals and anemones, as well as various kinds of crustaceans, mollusks, echinoderms, polychaetes, etc. Such a diverse array of species naturally requires a diversity of feed items, but little specific information is available about the feed requirements of most of these species. Instead of producing only