Baker P C, Hoff K M, Buda R E
Experientia. 1978 Nov 15;34(11):1521-2. doi: 10.1007/BF01932388.
Xenopus larvae raised from stage 21 in melatonin solution and upon a dark background had fewer head melanophores at stage 48 than control animals not exposed to melatonin. Rearing larvae in melatonin solution seems to mimic rearing larvae on a light background.