Globally, more than 2,500 species of ornamental fish are traded, but only 30-35 species of freshwater fish dominate the market. More than 90 % of freshwater fish are captive bred whereas only a few marine ornamentals are bred in captivity, according to Marine Products Export Development Authority (MPEDA). The global aquarium fish trade, including accessories and fish feed, is estimated at U.S. $ 18-20 billion. India contributes 0.61 % by quantity and 12.42 % by value (U.S. $) in the global ornamental fish trade, but the ornamental fish and aquatic plant industry is fast gaining importance due to its tremendous economic opportunities and prospects, it said in a release. The three-day Aqua Aquaria India, a national expo-cum-conference on aquaculture, here from Sunday would have four sessions on ornamental fishery on the inaugural day. They would be on marine aquarium trade in India, future prospects of the U.S. ornamental fish market, ecological considerations in ornamental aquarium trade. In addition, there would be sessions on topics such as the state of the shrimp aquaculture industry in Asia, shrimp nurseries, innovations in shrimp culture, octopus breeding and culture, prospects of marine finfish seed production in India and automation in commercial aquaculture. It would have sessions on many other topics like DNA labelling of seafood, marketing of value added products from aquaculture.