RESUMO
Since 1965, various works have pointed to electric rays [chiefly Torpedo marmorata and T. torpedo = T. ocellata] as an interesting material for the biological and physiological research on development [especially that of electric organs], growth and reproduction, In a review of the main published results, attention is called upon several points requiring new studies [buoyancy and its regulation during gestation time, neuroendocrine control of gestation, etc.]. T. torpedo, a much abundant species in the Bay of Tunis, seems by far the most well-suited material for this, because of its annual reproductive cycle. New results concerning T. m. are also presented: gestation length, embryo retention, and weight changes of the yolk sacs. The microscopic structure of the female genital tract is illustrated