Revisão da Metodologia e Sensibilidade do Tanaidáceo Kalliapseudes schubartii em Ensaios com Substâncias de Referência

Review of the protocol and sensibility of the tanaid Kalliapseudes schubartii in tests conducted with reference toxicants Since CONAMA resolution 344 (2004), which regulates the levels of contaminants in dredged material, the evaluation of the quality of sediments has received increased attention in Brazil in an attempt to establish standards for test protocols applied to benthic organisms and to investigate the sensitivity of this species. Regarding this issue, the present investigation had to main objectives. Firstly, to review test protocols for acute toxicity using the tanaidacea Kalliapseudes schubartii, and secondly to investigate the sensitivity of this species for reference toxicants usually employed in the marine ecotoxicology. Sensitivity experiments were carried out with the substances Zn, Cd, DSS (sodium dodecyl sulfate) and NH 3 in two salinity conditions (group 1: salinity 15 and group 2: local salinity 5.7; 7.3; 8.5; 10 e 21). In these experiments, mortality and mobility were assessed. Based on the threshold EC 50 and LC 50 , six days were needed to observe significant mobility effects, while seven days were needed to observed significant mortality effects. For zinc, in tests with individuals acclimatized in salinity 15 (group 1) there were found results with higher reproducibility. For group 1, were obtained LC 50 (7 days): Zn = 7.75 mg L –1 ; Cd = 0.29 mg L –1 ; DSS = 12.12 mg L –1 and nonionized ammonia = 3.16 mg L –1 . The results obtained to group 2 demonstrated that the acclimatization process of the organisms must interfere in their sensitivity, but, without a well defined visible pattern. The mobility as end point was less precise and therefore did not present advantages on the use of the mortality. In tests intended to evaluate the quality of the sediment, tanaids were generally found to be less sensitive than other organisms. However, using tanaids presented some advantages such as their wide salinity tolerance, preference for fine sediments, and high resistance to non-ionized ammonia.