Share thisThirty years among the Xenopus have led me to believe that we have made life with this frog way too complicated.
I would like to share with you what we feel will make a healthy Xenopus laevis research model in your lab or animal resource department. These suggestions are applicable to either the most sophisticated systems or to a single rubber tub.
There has been an enormous interest in tadpoles during the last few years. We first inject both the male and female adult Xenopus with 1000 units of human chorionic gonadotrophin (HCG). This is a single injection on the same day at the same time, usually in the morning. The opaque tanks are ten inches high and are half-filled with 70–72ºF well water since their normal breeding time is in the spring and at night. We cover the tanks to keep them dark and to prevent escape. The following morning, we remove the breeders from the tank, leaving behind the many fertilized eggs. Air stones are put into the tanks to generate gentle bubbles.
Tadpole water must not only be de-chlorinated but chloramines also have to be removed. We use well water, which is ideal, but if you must utilize city water systems, use a product called AmQuel+® and follow the directions on the label. It works immediately. Letting your water sit for 24 hours does not work as it does not remove chloramines. If you use distilled or de-ionized water, you must add back the salts or your tadpoles will die.
We do not de-jelly our eggs as you would do in your labs as we are only concerned with an abundant collection of tadpoles. Leaving the embryos undisturbed, we wait for them to become free swimming, taking usually four to five days before they have their first feeding. To introduce food into the tank before this point is useless since the embryos at that stage cannot feed and the eggs will become covered with fungus and die.