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Objective: To study the type, distribution, the growth and decline of toxins in Nassarius Sp. and the source of toxins to acquire the basis for the control of Nassarius Sp. poisonings., Methods: The toxicity of Nassarius Sp. was detected by mouse bioassay. The saxitoxin (STX), gonyau toxin (GTX), and tetrodo toxin (TTX) were detected by ELISA and HPLC., Results: Sixty-three poisonous Nassarius Sp. were identified in 127 samples collected from long-term monitoring sites. The detection rate was 49.6%. The detection rate of poisonous Nassarius Sp. was different in varies habitats (P < 0.01). The toxicity of Nassarius Sp. reached a peak in 1991 and hit the rock bottom in 1988. The rate of carrying toxins and the toxicity of detected toxins (STX, GTX and TTX) in Nassarius semiplicatus, Nassa succincta A. Adams and Niotha livescens were high., Conclusion: The toxins of Nassarius Sp. in Ningbo City were composed of TTX, STX or GTX, or both TTX and STX. The surveillance proved that some toxins present in Nassarius Sp. in Ningbo City. Poisoning could be caused by eating Nassarius Sp.

In parallel trials with the mouse bioassay, MIST Alert for Paralytic Shellfish Poisoning (PSP), a rapid diagnostic test for PSP, detected 100% of the toxic extracts in over 2100 regulatory samples. Toxic extracts contained at least 80 microg saxitoxin equivalents (STX equiv.) in 100 g of shellfish tissue, or more, as measured by the regulatory AOAC mouse bioassay. Only one potentially toxic sample, which contained 78 and 86 microg STX equiv./100 g shellfish tissue in two different mouse bioassays, was recorded as negative in one replicate of MIST Alert. All other toxic extracts among more than 2100 regulatory shellfish tissue samples were detected by MIST Alert for PSP. The MIST Alert for PSP also detected the majority of extracts containing PSP toxin greater than 32 microg STX equiv./100 g, which is the mouse bioassay detection limit. The MIST Alert for PSP gave a false positive result compared to the mouse bioassay at an average rate of about 14% over all sites, although some differences were seen between sites. Further analysis by high performance liquid chromatography (HPLC) of the (false positive) extracts showed that many contained PSP toxicity in the range of 20-40 microg STX equiv./100 g, below the level detectable by the mouse bioassay. The MIST Alert for PSP gave false positive results from extracts containing less than 20 microg STX equiv./100 g shellfish tissue only about 6% of the time. The PSP family of toxin analogues can occur in any combination in naturally contaminated shellfish tissue and the antibody mixture in the MIST Alert tests detect each of the different PSP toxin analogues with different efficacy. It is therefore impossible to provide an exact detection limit for the MIST Alert that would be applicable for all possible toxin profiles. Through the experience of comparison testing with the regulatory mouse bioassay in many parts of the world, with over 2100 different samples, the MIST Alert for PSP has proven its ability to detect all types of profiles of the PSP toxin analogues. The detection limit for MIST Alert for PSP was about 40 microg STX equiv./100 g for the 'average' profile of PSP toxin analogues. Since the detection limit depends on the toxin profile in the individual extract, it will also vary depending on the profile of analogues most commonly found at each geographic location. This was observed in our study. Over all sites in the trials, approximately 5% of samples below 40 microg STX equiv./100 g were positive, and 5% of samples between 40-80 microg STX equiv./100 g were negative. This is a reflection of the different analogue profiles found in naturally contaminated extracts, even after acid hydrolysis using the AOAC extraction method., (Copyright 2002 Elsevier Science Ltd.)

A recently developed commercial rapid test kit (MIST Alert) was assessed for determination of the presence of paralytic shellfish poisoning (PSP) toxins in shellfish. Several commercially important shellfish species obtained from the UK shellfish toxin monitoring program, containing a range of total PSP toxicities as determined by the mouse bioassay (MBA), were tested. The kit detected toxin in all samples containing the European Community tolerance level of 80 microg saxitoxin (STX) equivalents/100 g shellfish flesh as determined by the MBA. With one exception, the kit detected toxin in all samples that contained >40 microg STX equivalents/100 g according to the MBA. Among samples in which the MBA did not detect toxin, the kit disagreed in 25% of the tests, although further analysis by liquid chromatography (LC) and MBA of some samples confirmed the presence of toxins. These results suggest that MIST Alert may be suitable as an initial screen for PSP toxins as part of routine monitoring programs, thereby greatly reducing the number of MBAs. Trials were also performed by nonscientific personnel to evaluate the ease of use and interpretation of results obtained by MIST Alert. The results indicated that the kits could be readily used and accurately interpreted by individuals with no technical or scientific background.

Earthworms provide a major potential source of alternative food for polyphagous predators, such as carabid beetles, that are natural enemies of slugs, aphids and other agricultural pests. Non-pest prey may foster larger numbers of natural enemies, which then help to control pests, or alternatively may help to divert the predators away from pest control. An earthworm-specific monoclonal antibody was developed to study carabid-earthworm interactions in the field and assess the role of earthworms as alternative prey. The antibody could identify as little at 7 ng of earthworm protein in an ELISA, and could detect earthworm remains in the foregut of the carabid beetle Pterostichus melanarius for 64 h after consumption. Thirty-six per cent of field-collected beetles contained earthworm remains. Quantities of earthworm proteins in the beetle foreguts were negatively related to total foregut biomass, suggesting that earthworm consumption increased as total prey availability declined. There was also a negative relationship between foregut biomass and beetle numbers, but both quantities and concentrations of earthworm proteins in beetle foreguts were positively related to beetle numbers. This suggests that as beetle activity-density increased, total prey availability declined, or, as prey availability declined, beetles spent more time searching. In these circumstances, beetles fed to a greater extent on earthworms, an acceptable but nonpreferred food item. Earthworms may, therefore, provide an ideal alternative prey for P. melanarius, helping to sustain it when pest numbers are low but allowing it to perform a 'lying-in-wait' strategy, ready to switch back to feeding on pests when they become available.

Animal toxins are not to be understood as substances of random occurrence; they are of great importance in ecology. The venom-secreting organs have developed in a wide variety of ways and serve either as an offensive weapon or for protection against enemies. Accordingly, we may distinguish between actively venemous and passively venemous animals. There are other animals that are toxic rather by chance and due to extraneous factors; these we may call poisonous animals. Research into animal toxins is important from both the chemical and the biological points of view. In addition to basic knowledge, we may hope for interesting phylogenetic results from such research.