Exposure of fiddler crabs to nominal concentrations of TBT as low as

g/l during limb regeneration resulted in a variety of deformities, primarily a curved appearance. This was especially obvious in regenerated chelae in which the dactyl curved away from rather than toward the pollex. Developing embryos of the killifish were extremely variable in response to TBT. Some batches showed a dose-dependant delay and inhibition of hatching but nevertheless had some successfully hatching at 30

g/l. Other batches showed teratological effects at 30

g/l, primarily in the optic system. Other batches of embryos had 100% mortality during later embryonic stages and had none hatch, even at 3.0

g/l.