How to grow Xenopus laevis tadpole stages to adult

According to Weisz (1945), the tadpole stage can be divided into three forms, which broadly separate the tadpole stages into those occurring prior to the initiation of limb development, those covering limb development, and those encompassing metamorphosis. The 1st form corresponds to Nieuwkoop and Faber (NF, 1956) stages 45 through 47 (NF45-47) (Nieuwkoop and Faber 1994), beginning about 4 days after fertilization. Appearance of the hindlimb bud at NF48 defines the initiation of the 2nd form. This form lasts the longest (two or more months) and covers the primary growth phase of the tadpole and includes the stages when the hindlimbs and forelimbs develop (NF48-66). The 3rd form (NF59-66) features the onset and climax of metamorphosis and takes around 8 days to complete. During metamorphosis, the body undergoes dramatic changes internally and externally: culminating with the tails and gills being resorbed and the froglets starting to swim with their legs and respiring with their lungs. During this phase, the tadpole does not feed, while it changes from an herbivorous to an omnivorous diet. Maximal tadpole growth, especially during the 2nd form, is critically dependent on good husbandry practices. Here we describe a protocol for raising Xenopus laevis tadpoles through to adulthood. Each step may need to be modified depending on the aquaria used and local conditions. This protocol also may be used for raising Xenopus tropicalis tadpoles through metamorphosis, following minor modifications.