The Herpetological Journal

pp.29-38

Authors: J. R. Downie

Abstract: Eggs of the neotropical frog Leptodactylus fuscus (Anura: Leptodactylidae) are laid in foamy masses in burrows close to sites of temporary pools. After about two days, tadpoles hatch into the foam, but after two days further development, ifno rain has fallen, the tadpoles enter a period of developmental arrest, maintained until rain falls and the nest is inundated. Results reported here document the developmental status of the arrested tadpoles, and compare this with tadpoles that enter water immediately. Arrest involves a gradual slowing and eventual cessation of cell proliferation, a slowing of hatching gland degeneration, a cessation of limb bud morphogenesis and slowing of yolk utilization from intestinal lining cells. Arrest is not simply the result of lack of food, since the intestinal lining contains abundant yolk particles when it begins. The period of developmental arrest is not unlimited: around 20 days after egg deposition, the resultant tadpoles undergo progressive weight loss and eventually die; death occurred on average 27.5 days after egg deposition,under laboratory conditions.