Distasteful, noxious, and toxic secretions from skin glands have been demonstrated to play important antipredatory roles in amphibians. Previous studies suggest that the Long-toed Salamander (Ambystoma macrodactylum), a widely distributed urodele found near the northern limit of its range in northern British Columbia, is distasteful to predators. The source of this distastefulness has not been exclusively identified. Our objectives were to isolate the skin secretions of the Long-toed Salamander through electrical stimulation of its granular glands and bioassay this secretion for antipredatory effects with crayfish. Previous studies suggested that proteins play an important role in these secretions; therefore, we tested for their presence and utility. The feeding response of crayfish to control food pellets was compared to pellets incorporating raw salamander skin secretions and to pellets incorporating boiled secretions. Significantly more crayfish consumed the control pellets than the raw skin secretion pellets, indicating unpalatability of these skin secretions. Thus, skin secretions appear to have an important antipredatory function. Skin secretions tested positive for presence of proteins, but the feeding response of crayfish to raw and boiled secretions was not significantly different, indicating that proteins were either only partially denatured by boiling, or are not exclusively responsible for the antipredatory nature of the secretions. A very low concentration of secretion was required to illicit a significant antifeedant response in crayfish, and we discuss the possible implications of this in relation to a proposed dual function of the Long-toed Salamander's granular glands in nutrient storage and the energetic requirements of an amphibian in its northern range.