The ternary system Ni2+(AOT)(2) (nickel 2-bis[2-ethythexyl] sulfosuccinate)/water/isooctane presents w/o and o/w microemulsions with a Winsor progression (2Phi - 3Phi - 2Phi), without the addition of salt; the "fish diagram" was obtained for alpha = 0.5 and gamma = 0.02-0.22. Using static and dynamic light scattering the micellar size, the ratio of water to surfactant, and the density of micelles for this system were estimated. In addition, the mean interfacial curvature as a function of temperature was obtained. (C) 2004 Elsevier Inc. All rights reserved.