Toxicity to snails

Traversianal, though not dothistromin, was also tested for toxicity to snail (Biomphalaria sp ) and was found to be unusually toxic, causing 100% mortality at 3 2 x 10" M (10 p p m ) and 25% at 3.2 x 10 6 M. This activity level is equal to or greater than that observed for helenalin, the most active of several compounds tested previously in the UBC laboratory (38), as part of a program on potentially medicinally useful natural products Molluscicides, particularly naturally occurring ones (39), are of much current interest as agents for the control of snails as vectors of schistosomiasis (40). 

Bay leaf and some of its volatile compounds (esp. cineole, phenylhydrazine, gera-niol, and piperidine) have been shown to repel cockroaches. Aqueous extracts of the leaves and flowers have shown toxicity to snails (Biomphalaria glabrata) ... 

Soucek, D.J. and G.R Noblet. 1998. Copper toxicity to the endoparasitic trematode (Posthodiplostomum minimum) relative to physid snail and bluegill sumfish intermediate hosts. Environ. Toxicol. Chem. 17 2512-2516. 

Mercury-zinc mixtures were more-than-additive in toxicity to oyster larvae (Sprague 1986). Preexposure of mussels (Mytilus edulis) to 50 pg Zn/L for 28 days conferred increased tolerance to 75 pg inorganic mercury/L (Roesijadi and Fellingham 1987). Zinc inhibited the accumulation of mercury in marine snails and crustaceans (Andersen et al. 1989). 

DDT was very toxic to daphnids. As a result, restocking was required at the 100 ppm treatment on days 5, 17, 31 and 40 (Table IV). Repeated restocking at the 1000 ppm treatment failed to maintain a population for more than one day while daphnids survived and reproduced at the 10 ppm rate. Daphnids, because of their large surface-area-to-mass ratio, tended to respond to changes in solution DDT levels more rapidly than did fish or snails. Algae were, of course, not affected by DDT (Table V) and the concentration of in the tissue responded to the solution concentration in a very direct and rapid manner. 

Uses Pure azinphos-methyl is a white crystalline solid technical azinphos-methyl is a brown waxy solid. Based on toxicity, the USEPA has grouped it under RUP. Azinphos-methyl is a highly persistent, broad-spectrum insecticide. It is used for the control of mites and ticks, and it is poisonous to snails and slugs. It also is used in the control of many insect pests on a wide variety of fruit, vegetable, nut, and held crops, as well as on ornamentals, tobacco, and forest and shade trees. Outside the United States, azinphos-methyl is used in lowland rice production. Azinphos-methyl is available in emulsihable liquid, liquid flowable, ultra-low volume (ULV) liquid, and wettable powder formulations.28,29... 

An informative paper by Di Toro et al. (1991), on predicting the acute toxicity of Cd and Ni in sediments by assessing the acid volatile suflide (AVS), illustrates that the sediment properties that determine the concentration (activity) of the sediment in the interstitial water determine the fraction of the metal that is bioavailable and potentially toxic. The study of Di Toro et al. is based on measurements of acute toxicity to benthic organisms (amphipodes, oligo-chaetes, and snails). It is shown that this toxicity is essentially related to the free metal ions in solubility equilibrium with the solid metal sulfides present. 

Propanil is toxic to aquatic invertebrates (e.g., crayfish, worms, snails) and to fish. It is moderately toxic to birds. 

Tributyltin and tributyltin oxide are still used on boats and ships to prevent growth of barnacles. They are extremely toxic for many invertebrates in the sea, notably some snails whose sexual organs develop abnormally. In these snails the female develops a penis. In oysters and other bivalves, their shells become too thick. Tributyltin must be regarded as one of the most serious environmental pollutants, but contrary to the lower analogues, trimethyl tin and triethyltin, they are not very toxic to man and other mammals. Trimethyltin is of considerable interest for neurotoxicologists because it leads specifically to atrophy of the center for short-term memory, the hippocampus. The ethyl analogue has other serious detrimental effects on the brain. 

According to Polster and Halacka (1972), triphenyltin compounds are very toxic to aquatic snails, small fish and zooplankton the concentration of these compounds in water must therefore not exceed 3 gg/l. It is harmless to bees. 

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