Present Status Of Production, Comparison Of Biological Characteristics And Mornitoring Of Toxin Content Of Cultured Takifugu Puffer Fishs In China

1 At present, China puffer fish farming technology is quite mature, to further expand the domestic market of puffer fish scientifically and safely, the distribution of cultured species and cultured region and the farming methods have been investigated. According to the results, a total of 565 specimens of cultured puffer fish (Takifugu rubripes, T. fasciatus or T.obscurus, T. flavidus, and T. bimaculatus) were collected from five provinces (Liaoning province, Hebei province, Shandong province, Jiangsu province and Fujian province). Takifugu rubripes was farmed in Liaoning province, Hebei province and Shandong province, T. flavidus was farmed in Shandong and Jangsu province, T. bimaculatus was farmed in Shandong, Jangsu and Fujian province, and T. fasciatus was only farmed in Jangsu by the reason of endemic fresh water puffer fish species in China. Cultured Takifugu pseudommus and Takifugu xanthopterus were not collected. The production of puffer using closed systems indoor in winter was commonly in Northern provinces of Liaoning, Hebei and Shandong, and in summer, both of indoor and net cages were used in Northern province. The production of puffer fish in Fujian province was commonly cultured in net cages. It is interesting that body colour variation was observable between different province. The body colour of cultured T. bimaculatus is gradually dark from north of Shandong province to south of Fujian province, the possible reason is the different of illumination and temperature between north and south procince.2 Data about the growth, the rate of skin and meat, liver and gonad index of four species of cultured Takifugu puffer fish were collected and compared. The differences of ineconomic traits of Takifugu puffer fish were analysis.It was hope that people can develop the puffer fish farming according local conditions using the provided scientific data. The length-weight relationship equations with W= a L^b were concluded. The results showed that the length-weight relationship equations of total T.rubripes was W=0.3516L^2.2818 , (R²=0.6406), female fish was W=0.5664L^2.1337(R²=0.6394), male fish was W=0.2112L^2.4453(R²=0.6426). Because of narrow range of T.flavidus, T.bimaculatus and T.fasciatus length, The equations with W=aL^b were not concluded. When the four species were to be commercial size, the growth rate of body weight/body length of T.rubripes is the highest than other three species, followed by T.fasciatus. Because T.bimaculatus and T.flavidus belong to small size species , the growth of body weight were quite slow. For the same species, the growth rate of body weight/body length of fishs from southern province were generally higher than northern.For the weight of skin ,muscle,liver and gonad-body weight/body length relationship of the four cultured species puffer fish, it is showed that linear relationship between the growth of skin,muscle and liver and body weight could be observable. The generally exponential relationship between the growth of skin,muscle and liver and body length could be showed. When puffer fish up to certain body weight or body length, the growth of gonad weight, particularly ovary of part of them were faster than before, Except to T.fasciatus.(T.rubripes is generally up to 800g,30cm, T.bimaculatus and T.flavidus is generally up to 250g,17cm).But other part of them were slow. The growth rate of goand weight of fishs from southern province were generally higher than northern.The rate of skin, muscle and liver weight to body weight of the four species were compared. The results showed that the the T.rubripes is highest in rate of skin, T.fasciatus is highest in rate of muscle and liver, while T.bimaculatus is lowest in either of the three tissues. For the total rate of the three tissues, T.fasciatus is highest in the four species. It can be concluded that the use ratio of T.fasciatus is highest in the four species either from the point of view of food consumption economy and toxins extraction, and T.bimaculatus lowestThe anatomic data were also got including digestive system, urogenital system, and brain.3 The study of toxicity or tetrodotoxin (TTX) content of cultured puffer fish in China was conducted using mouse assay in order to provide first-hand data to further expand the domestic market of puffer fish scientifically and safely, to promote economic and cultural development, to ease trade conflicts. Toxicity of skin, muscle, liver and testis/ovary was examined by methods based on a mouse assay for TTX. Results indicated that the skin, muscle, liver and testis of specimens were'non-toxic'in the mouse assays (less than 10 MU g^-1 or 2.2μg g^-1) from the point of view of food hygiene. However, TTX was detected from an ovary sample of the cultured T. rubripes collected from the Shandong province in March 2008, which was 125.43 MU g^-1 tissue. The average TTX content in muscle, liver and skin of T. rubripes from Hebei and Shandong provinces were highest in May or July (1.31, 0.90, 0.62 MU g^-1, respectively in Hebei, and 1.57, 0.32, 0.16MU g^-1, respectively in Shandong), and lowest in January (less than 0.1 MU g^-1 or 0.02μg g^-1).The variation of toxicity between species, individual, seasons and sex were present in cultured pufferfish as well as wild puffer fish. The variation of toxicity distribution of different tissues could be found between sea water farming species and fresh water farming species. It was found that the muscles of the three marine cultured puffer fish generally contained the highest toxicity, followed by liver and skin, and the skin of the cultured T. fasciatus had the highest toxicity, followed by muscle and liver; The toxicity of sample which collected in every season in the case of T. rubripes in Hebei and Shandong was highest in summer, and lowest in winter; The toxicity of female fish was higher than that of male fish, one toxic ovary sample in this study contained 125.43 MU g^-1 tissue, while no TTX detectable testis could be found. It is worth noting that the levels of toxicity of cultured puffer fish is much lower than wild puffer fish.4 The skin, muscle and liver groups of T. rubripes from ShanDong provinces and several ovaries were measured by Enzyme-linked immunosorbent assay(ELISA) at same time. The results indicated that the mouse method and ELISA method have no significant difference. Y=1.3977 X+0.0022 (r²)为0.9739 . The skin, muscle and liver was found to contain traces of toxins, and present anniversary variation.The origin of TTX in puffer fish should be exogenous. The TTX accumulation mechanism in puffer fish have no significant difference between cultured and wild. The level of toxin content is much more related to the TTX origin in the environment. It is still careful that the TTX origin should be cut off, and the course of farming should be reinforce the management.5 The skin, muscle and liver of T. rubripes from Hebei province and one ovary of T. rubripes from Shandong province were ditected by HPLC assay. The result indicated that no detectable TTX in the skin and muscle, only observable TTX in liver which couldn't be quantitative accurately. While the results of ovary using HPLC was much more higher than mouse assay, the author supposed that great amount TTXs of which toxicity was lower than TTX should be exists in ovary. Further studies still remain conducted.