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3B - Marine toxicity evaluation: current practice and applications (MOP/161) Effects of exposure to lead on histology of Mesopodopsis slabberi (Crustacea, Mysidacea). Sardo, Ana Margarida1, Azeiteiro, Ulisses2, Morgado, Fernando1, 1 Department of Biology, University of Aveiro, Aveiro, Aveiro, Portugal2 IMAR, University of Coimbra, Coimbra, Coimbra, Portugal ABSTRACT- M. slabberi is a euryhaline and suprabenthic mysid that presents a wide geographic distribution and is one of the most important mysids species in coastal shallow waters. Frequently occurs in estuarine systems where it is usually, the most abundant mysid. The toxicity of lead has been studied using the estuarine mysid M. slabberi. Lead is a heavy metal, well known as a toxic material. The human activities, such as industries and transports are the most important sources of lead pollution. Furthermore, lead is becoming more common in the marine environment, into which this element is introduced by effluents or rain. The toxicity of lead is due to interaction with the functional groups of enzymes, as this metal has a strong affinity for metal-binding proteins, principally proteins binding lead and metallothioneins. Within the cell, lead unites closely with these proteins. It is necessary to study the ecotoxicology of lead in marine environment, since this metal can be transmitted through the trophic webs to higher biotic levels. After a period of two days acclimation, mysids were exposed to different sublethal lead (as lead acetate - (CH3COO)2Pb.3H2O) concentrations, for a period of 48h.The concentrations tested were 0.005, 0.01, 0.02, 0.04, 0.08, 0.16, 0.32 and 0.64 mg/l, with seven replicates for each concentration. Organisms were killed and a standard histology process (with little modifications, due to the specificity of the specie and chitinous coating). Histological effects were analyzed in several tissues and results are presented and discussed in this work, to be used as complementary diagnostic to toxic detection in marine environment. Key words: Mesopodopsis slabberi, toxicology, lead, histology |
