About Hydrophilus acuminatus Motschulsky, 1854
Hydrophilus acuminatus (described by Motschulsky in 1854) reaches a body length of 33–42 millimetres (1.3–1.7 inches). Its body has a base color of dark brown or black. This species of beetle has streamlined bodies and heads adapted for aquatic life, though they are not powerful swimmers. When diving, they carry an air bubble under their elytra, and their entire body is covered in fine hairs that trap an additional layer of air. Adult Hydrophilus acuminatus are mainly vegetarian, feeding on aquatic plants, while the larvae are carnivorous, feeding on tadpoles, snails, and small fish. This species occurs in the Russian Far East, China, Japan, and Korea.
