Identification of a New Stage in Salamandra infraimmaculata Metamorphosis

We examined various water bodies in which fire salamander (Salamandra infraimmaculata) larvae were growing and showed significant variation in growth rate and completion of metamorphosis depending on the habitat-seasonal pond, spring stream, or water hole. The phenomenon described herein involves larvae found in a water hole at a late stage of metamorphosis with highly developed gills, unable to leave the hole and complete metamorphosis. We hypothesize that the gills are an adaptation to the summer period, until the hole fills with water, allowing the larvae to complete metamorphosis and transition to terrestrial life.