Investigation on region distribution of poisonous nassarius Sp in Ningbo city

  Objective   To investigate the region distribution of poiso nous Nassarious sp and study the difference in the paralytic shellfish poisoning(PSP)toxins in various habitats for the control of poisoning caused by poisonous Nassar ious sp.

  Methods  

  Results   were achieved annually with the Association of Official Analytical Chemists(AOAC)and CIQ mouse bioassay in which the toxin intensity was determined according to the standard for shellfish paralytic toxins from FDA in USA.

  Results   Among the 127 samples measured in 18 years, the highest concentration of PSP toxins, 1.900 MU in 100 g of tissue, was found in 1991 and the lowestin 1988 with a concentration of 403 MU in 100 g of tissue.Toxin concentration varied in a certain range in other years.The per centage of poisonous Nassarious sp detected was 31.43%, 39.29%, 73.08% and 25.00% in Zhenghai zone, Beilun zone, Ninghai county and Fenghua city, respectively, which was significantly different(P < 0.01).While no significant difference existed among the investigated 3 regions excluding Ninghai county(P > 0.05).The average concentration of PSP toxins from Nassarious sp in Xiangshan county, a new habitat, was below 400 MU/100 g tissue and no poisonous Nassarious sp was found there.

  Conclusion   High concentration of PSP toxins was detected in Nassarious sp tissue in Ningbo city, which was a major cause of food poisoning.Difference in toxicology existed among Nassarious sp in various habitats while poisonous Nassarious sp was most commonly found in Ninghai county.There was relationship between the distribution and toxic intensity of poisonous Nassarious sp and its habitats.The toxic intensity fluctuated without regularity.