Tabla de Contenidos: “…-- 3.3 Do all placozoans harbor both G. incantans and R. eludens? -- 3.4 Intracellular locations of the placozoan symbionts -- 3.5 Unusual mitochondria in placozoan fiber cells and their possible relationship to symbiosis -- 3.6 Molecular inferences on the nature of the Trichoplax-bacteria symbioses -- 3.7 How are the bacterial symbionts of placozoans transmitted between generations? …”