Influence of social stress in the establishment of Rigor Mortis and in cortisol plasmatic levels in Nile Tilapia Oreochromis niloticus - Corrêa, Sandro Alves; Verreschi, Denise Cerávolo; Viegas, Elisabete Maria Macedo; Iseki, Katia Kiyomi (World Aquaculture, 2003)