Snails concentration

The lethal activity of the isobutylamides on B. glabratus is shown in Table III. Molluscicidal activity was monitored as described previously.Briefly, snails of uniform sizes (average diameter of the shell 9 mm) were placed 2 snails/ concentration into deionized water solutions containing known concentrations of the isobutylamides. Unlike the relative activities of the isobutylamides on the tested insect species, fagaramide (1 ) and N-isobutyl-2E,4E -octadienamide ( ) were more potent molluscicides than were pellitorine (4) or piperlongumine (2). 

Scale of Operation Voltammetry is routinely used to analyze samples at the parts-per-million level and, in some cases, can be used to detect analytes at the parts-per-billion or parts-per-trillion level. Most analyses are carried out in conventional electrochemical cells using macro samples however, microcells are available that require as little as 50 pL of sample. Microelectrodes, with diameters as small as 2 pm, allow voltammetric measurements to be made on even smaller samples. For example, the concentration of glucose in 200-pm pond snail neurons has been successfully monitored using a 2-pm amperometric glucose electrode. ... 

Copper has been employed as a bactericide, moUuscicide, and fungicide for a long time and is of importance in the control of schistosomiasis (see also Antiparasitic AGENTS, ANTHELMINTICS FUNGICIDES, AGRICULTURAL). Addition of copper to lake water acts as an efficient deterrent to transmittal of the disease by eliminating snails that act as hosts for the responsible parasite. Copper is commonly utilized at ca 0.1 mg/L as an algicide. In fresh water, acute toxicosis in fish is unusual if the copper concentration is below 0.025 mg/L (70) (see Poisons, economic). 

Transfer of copper from wood treated with chromated copper arsenate (CCA) occurs in estuarine algae (Ulva, Enteromorpha), American oysters, mud snails (Nassarius obsoletus), and fiddler crabs (IJca spp. Weis and Weis 1992). Algae, barnacles, andmussels from CCA-treated lumber show elevated concentrations of copper when compared to reference sites. The epibiotic estuarine community that... 

Median BCF values in aquatic biota exposed to various concentrations of Pb+2 for 14 to 140 days varied from about 42 in fish to 2570 in mussels intermediate values were 536 for oysters, 500 for insects, 725 for algae, and 1700 for snails (USEPA 1985). There are several notable exceptions to this array significantly higher values have been reported in crustacean hepatopancreas (Heyraud and Cherry 1979), in various species of freshwater invertebrates (Spehar et al. 1978), in fish bone (Demayo et al. 1982) and liver (Haux and Larsson 1982), and in whole oysters (Zaroogian et al. 1979). In oysters, for example, BCF values varied from 3450 to 6600 after exposure to solutions... 

Russo, J. and Lagidick, L., Effects of environmental concentrations of atrazine on hemocyte density and phagocytic activity of pond snails Lymnea stagnalis, Environ. Pollut., 127, 303, 2004. 

Significant concentrations of cyanotoxins have been found to accumulate in the tissues of macroinvertebrates such as mollusks and crustaceans, presenting an indirect route of exposure for invertebrates, fish, and aquatic mammals at higher trophic levels (Negri and Jones 1995). In natural systems, mortality among benthic invertebrate herbivores is probably low because most bloom-forming bacteria are planktonic and only periodically come into contact with the benthos. Nevertheless, Kotak et al. (1996) determined that enhanced mortality of snails at the end of a bloom cycle in Canadian lakes was due to consumption of Microcystis cells that had formed a scum on the surface of macrophytes. Oberemm et al. (1999) found that aqueous microcystins, saxitoxins, and anatoxin-a all resulted in developmental delays in fish and salamander embryos. Interestingly, more severe malformations and enhanced mortality were observed when larvae were exposed to crude cyanobacterial extracts than to pure toxins applied at natural concentrations (Oberemm et al. 1999). 

The results indicated that yolk diet significantly increased the concentration of pigments while parasitism has no significant effect on the amount of pigments. The data demonstrate that the RP-HPTLC method can be used for the determination of pigments in snails [21],... 

Concentrations significantly reduced (Student s f-test, P<0.05) compared with snails on L diet. 

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