The Japanese Fisheries Research and Education Agency (FRA) of the National Research and Development Agency announced on 25 December that it will begin test sales of leopard coral grouper in both Japan and China in order to study a new aquaculture business model.
Leopard coral grouper (Plectropomus leopardus) are also called “coral trout,” though they are genetically grouper. Bright orange with many blue spots, they inhabit tropical and subtropical areas of the Indian and Pacific oceans. In Japan, they are found around Okinawa, where they are known as “akajin,” while in the rest of Japan, they are called “suji-ara.” The FRA will test-market the fish under the name “Ryukyu Akashin,” as Okinawa is in the Ryukyu Islands.
The FRA has been trying to develop the species for many years with an eye towards growing exports. The FRA’s Seikai National Fisheries Research Institute (SNFRI), based in Nagasaki, began researching leopard coral grouper farming in 1985. The researchers successfully produced juveniles from wild-caught parent fish in 2009, but it was not until June of 2016 that they obtained fertilized eggs from captive-hatched leopard coral grouper. Almost a quarter of the 29,000 resulting fry survived to maturity, thus achieving closed-cycle farming. The plan is to ship about 7,000 fish of 400 to 500 grams each this year and around 10,000 next year to investigate the profitability.
The fry are raised entirely in tanks on land, and as they grow, the fish are moved to larger tanks to maintain the proper stocking density. Scientists are also working to develop optimal feeding methods taking into account changes in metabolism due to circadian rhythm and time and frequency of feeding. The land-based system could conceivably be used anywhere, though the current effort is to raise them in Okinawa, where they are already known as a high-value delicacy, and to export them to nearby China.
Leopard coral grouper garners high market prices as an ingredient in Chinese cuisine, and the FRA considers it a promising candidate for export there. Grouper of all kinds are popular for special festive occasions, and bright red is considered to be a lucky or celebratory color. The Chinese trading portal Alibaba lists frozen leopard coral grouper at USD 26.00 (JPY 2,859, EUR 22.89) per kilogram from Indonesia, and USD 19.00 (JPY 2,089, EUR 16.73) from Malaysia. Fresh and live fish fetch higher prices.
Keisuke Murakami, a researcher with the FRA, told SeafoodSource the fish would be sold both fresh and frozen, but not live for the time being. It is possible to carry live grouper by boat from Okinawa to China, but it requires live import registration, he said.
Closed-cycle breeding is more expensive than rearing fish spawned from wild-caught parents, but as the natural resource is under pressure both from fishing and from reductions in its coral habitat, this may become more important. The ability to breed strains that have desirable characteristics like faster weight-gain and bright red coloration may also give advantages to fish raised in the closed-cycle method.
Leopard coral grouper is also farmed in Taiwan. One company that has been producing them there is Hydean Biotechnology, which sell markets them under the Puredise brand. The company promotes an integrated production model that it calls a “cultivation chain.” It includes a broodstock facility, a plankton factory, a hatchery, a nursery, and a grow-out facility – all indoors in a controled environment. The used water produced by the facility is subsequently used in hydroponic vegetable cultivation, with the fish feces used as fertilizer. The Taipei-based company raises giant grouper and leopard coral grouper and eel. It also utilizes specific pathogen-free (SPF) broodstock.
Wild-caught leopard coral grouper can be as source of ciguatera poisoning and is usually listed on warning posters in tropical resort areas where divers or boaters might catch them, but these poisons come from dinoflagellates (Gambierdiscus toxicus) in the food chain and not from the fish themselves.
