The Family Hynobiidae is a group of primitive salamanders primarily found in Asia, including Japan, China, and Russia. These salamanders are typically small to medium-sized, with external fertilization in most species, which is unusual among salamanders. They are mostly aquatic or semi-aquatic, living in streams, ponds, and moist forest habitats, and they lay eggs in water or under moist substrates. Hynobiids are carnivorous, feeding on insects, worms, and small invertebrates. Their ecological role includes controlling insect populations and serving as indicators of freshwater ecosystem health due to their sensitivity to environmental changes.