**Author details**

ed. Indicators of stress at several levels of biological organization have been used to evaluate

A variety of *in vitro* and *in vivo* assays with fish are being used as model systems for toxico‐ logical, biochemical and developmental studies (Powers, 1989). Fish species such as rainbow trout *(Oncorhynchus mykiss),* carpas, catfish and Japanese medaka *(Oryzias latipes)* have been used extensively as test organisms for studies of carcinogenesis. A variety of teleost species have been used to study the development of early life stages of fish and the teratogenic ef‐ fects of environmental contaminants (Wisk; Cooper, 1990). Fish respond in a manner similar to mammalian test species to chemicals that induce peroxisome proliferation in hepatocytes (Yang et al., 1990), and oxidative damage in hepatocytes (Washburn; Di Giulio, 1989). Hep‐ atic cytochrome P-450 monooxygenases in fish also metabolize many carcinogens in a man‐ ner analogous to mammalian organisms (Stegeman; Lech, 1991). The advantages of using fish as model organisms include the ease with which teleosts, especially small aquarium species, can be held in the laboratory and exposed to toxic chemicals. Since fish often re‐ spond to toxicants in a manner similar to higher vertebrates, they can be used to screen for chemicals that have the potential to cause teratogenic and carcinogenic effects in humans. However, the main application for model systems with fish is to determine the distribution and toxic effects of chemical contaminants in the aquatic environment. Industrial and urban discharges are responsible for high concentrations of toxic substances in the aquatic environ‐ ment, although in many countries, regulatory activity is beginning to limit point-source dis‐

Animal alternatives research has historically focused on human safety assessments and has only recently been extended to environmental testing. This is particularly for those assays that involve the use of fish. A number of alternatives are being pursued by the scientific community including the fish embryo toxicity (FET) test, a proposed replacement alterna‐ tive to the acute fish test. Discussion of the FET methodology and its application in environ‐ mental assessments on a global level was needed. With this emerging issue in mind, the ILSI Health and Environmental Sciences Institute (HESI) and the European Centre for Ecotoxi‐ cology and Toxicology of Chemicals (ECETOC) held an International Workshop on the Ap‐ plication of the Fish Embryo Test as an Animal Alternative Method in Hazard and Risk

Environmental pollution is of current environmental concern. It is therefore necessary to find solutions to determine environmental contamination, because the organisms are contin‐ uously exposed to a variety of anthropogenic toxicants daily released to the environmental. The silver catfish have been used for bioindicator of environmental contamination for many researches and can be used to aquatic biological systems. Moreover, a considerable expan‐ sion of knowledge in using various model species which are easily cultured and have lesion

effects of contaminants at the organism level.

212 New Advances and Contributions to Fish Biology

charges of toxic chemicals to our water resources.

Assessment and Scientific Research in March, 2008.

induction times of relatively short duration, such silver catfish.

**7. Conclusion**

Cláudia Turra Pimpão1\*, Ênio Moura2 , Ana Carolina Fredianelli3 , Luciana G. Galeb3 , Rita Maria V. Mangrich Rocha4 and Francisco P. Montanha5

1 Laboratory of Pharmacology and Toxicology/PUCPR, College of Agricultural, Environ‐ mental Sciences and Veterinary Medicine,Pontifícia Universidade Católica do Paraná, Curi‐ tiba, Brazil

2 Service of Medical Genetics/PUCPR, College of Agricultural, Environmental Sciences and Veterinary Medicine,Pontifícia Universidade Católica do Paraná, Curitiba, Brazil

3 College of Agricultural, Environmental Sciences and Veterinary Medicine,Pontifícia Uni‐ versidade Católica do Paraná, Curitiba, Brazil

4 Service of Veterinary Clinical Pathology/PUCPR, College of Agricultural, Environmental Sciences and Veterinary Medicine,Pontifícia Universidade Católica do Paraná, Curitiba, Brazil

5 Laboratory of Pharmacology and Toxicology/FAMED, College of Agricultural, Environ‐ mental Sciences and Veterinary Medicine,Pontifícia Universidade Católica do Paraná, Curi‐ tiba, Brazil
