EFFECTS OF VITAMIN A ON THE DEVELOPMENT OF FROG, RANA BREVICEPS (SCHNEIDER)

Embryos of frog, Rana breviceps at blastula stage were reared in solutions containing 1 I.U./ml, 5 I.U./ml; 10 I.U./ml; 15 I.U./ml; 20I.U./ml and 30 I.U./ml solution of vitamin A plamitate at room temperature. Hatching was not affected, but the treatment continued during larval period resulted in the development of abnormalities like exencephaly, depigmentation; oedematons body; beaked mouth and curved tail. The general body growth and development of mouth armature; fins and hind limbs were greatly inhibited by high amount of the vitamin, its low concentrations also caused a great retardation. It is concluded that vitamin A excess produces a variety of effect on tadpoles which are related to the amount administered.