Single hand manual frog restraint for gonadotropin injection and egg collection. (A) View from the dorsal surface with the index finger in-between both legs, one of the legs being held between the index and the middle fingers, the thumb located around the waist on the other side of the frog. (B) View of the hold from the ventral surface with the index finger between the legs, the middle finger and the thumb located on the waist on the opposite sides of the frog, and the tip of the little finger pressed against the throat to secure the head against the base of the palm of the hand, thus aiding to cover the eyes. (C) The frog in fully restrained hold with one of the legs pulled back against the abdomen and a needle ready for injection through the dorsal surface. (D) X. laevis female adult with the general location of the dorsal posterior lymph sacs, the injection target, outlined in red. (E) A more relaxed hold on the female with neither leg fully restrained against the abdomen and with a needle ready for injection through the dorsal surface.