1. Departamento de Engenharia Ambiental, Universidade Estadual do Centro-Oeste, Rua Professora Maria Roza Zanon de Almeida, Engenheiro Gutierrez, CEP 84500-000 - Irati - PR, Brazil; e-mail: elynton@yahoo.com
2. Department of Biology, Faculty of Education, Palacky University, Purkrabska 2, CZ-77140 Olomouc, Czech Republic; e-mail: milada.bocakova@upol.cz