They are from estuaries. From the reading I have done, sounds like the adults are often in full freshwater and sometimes low low end brackish (1.005). I am keepign them in freshwater. If they do well, I will continue to do so. If they start looking not too hot, I will try adding salt. They came in as a surprise, so I wasn't really prepared for them. They were on a fw list though so I can only assume they were beign kept in full fw.