Croaker is a popular delicacy owing to its tender and delicious texture. Fish maw, made from its swim bladder, is a widely known and valuable supplement that has a higher economic value than the flesh of the fish. To promote the development of diverse fish species in Taiwan’s mariculture, the Fisheries Research Institute (TFRIN, a division of the Council of Agriculture, Executive Yuan) has joined hands with cage fish farmers in Penghu to experimentally cultivate Japanese meagre (Argyrosomus japonicus), which is a type of croaker. After years of effort, the successful mass production of fish fry has been achieved, and the fish farming results have been remarkably promising. In the future, locals will be able to savour the fish at more wallet-friendly prices.
The Japanese meagre, also known as the Qixing croaker, water croaker, and white croaker, has a high temperature tolerance (8-34°C), fast growth, and a high feed conversion rate. It is regarded as a mariculture species with strong developmental potential, as it can fetch up to NT$400-500 per kilogram, while its fish maw can fetch up to NT$180-225 per 100 grams. In the past, mass cultivation had been unsuccessful due to insufficient seedlings, rampant cannibalism, and transportation difficulties. Since 2001, however, the TFRIN has been conducting research on the mass production of Japanese meagre fry. Even though brood fish were successfully cultivated, the popularity of grouper aquaculture and the demand for groupers back then had hindered the mass cultivation of the Japanese meagre. After the record cold snap in 2016, however, the Japanese meagre was discovered to be able to withstand temperatures as low as 7-8°C. Therefore, the TFRIN continued its cooperation with private aquaculture operators to collect wild Japanese meagre for fry cultivation.
The cultivation experiment results showed that the male and female Japanese meagre reached maturity around three and four years of age, respectively. After hatching, the fry were fed on oyster zygotes, rotifers, copepods, minced fish, and adult brine shrimp, and attained a one-inch body length after 40 days. Throughout the intermediate growth stage, the daily feeding frequency was increased to reduce variations in fry size and cannibalism and, thereby, enhance growth rates.
This year (2019), the TFRIN announced that after three years of research and development, the cultivation of Japanese meagre in fish ponds has achieved a mass production scale. Up to a hundred thousand fry can be raised per batch, and transportation difficulties have been overcome, as the fry are able to withstand the 12-15 hours of long distance transport to Penghu for cage farming. The mass cultivation of the fish is expected to be implemented soon, and locals will then be able to savour the fish’s tender, chewy, and delicious texture at affordable prices. Moreover, the promotion of the fish maw industry can drive its potential as an industry with high economic value.