As aquatic toxicologists, we are introduced to a large number of invertebrate and vertebrate species. Forexample, when Roesijadi 1 reviewed the metallothioneins, including their role in metal regulation and toxicity of aquatic animals, he presented information on 34 bony and cartilaginous fishes, 4 echinoderms, 2 insects, II crustaceans, 18 mollusks, and 5 annelids. Similarly, Stegeman2 reviewed cytochromes P450 in fishes and included findings from more than 20 species. A recent listing of the bony and cartilaginous fishes in which tumors of the liver have been reported included 74 species.3