The tail‐darkening reaction of phyllomedusine tadpoles

A tail‐darkening reaction is described for tadpoles of the phyllomedusine frogs, Agalychnis dacnicolor and Phyllomedusa trinitatus . Tails are pale in the light because melanophores in the dermis of the fin are punctate. In darkness the melanophores become dendritic and the tail appears black. This photosensitivity is local since tail‐darkening in isolated tails and in intact tadpoles occurs equally well. Tails cultured for many days retain fully the capacity for tail darkening. Correlations between tail darkening and filter feeding and swimming are made from comparisons with Xenopus tadpoles.