Halobates is the only known insect genus with species that live on the open ocean. These insects are commonly called sea skaters or ocean striders, and they use the water’s surface tension to walk, row, and leap across offshore waters.
The genus contains more than 40 species, but the wording hides an important nuance: most Halobates species live in coastal marine habitats. Five species—Halobates micans, H. germanus, H. sericeus, H. splendens, and H. sobrinus—are truly pelagic, spending their lives on the surface of the open ocean. They are the only known insects adapted to this offshore environment.
Halobates cannot dive like many aquatic insects. Their middle legs provide propulsion, while the front legs seize prey and the rear legs help steer. Oceanic species feed on floating organisms, zooplankton, fish eggs, and other material at the surface. Females attach eggs to floating objects such as feathers, driftwood, cuttlebone, and, increasingly, plastic debris. The genus was first collected scientifically during the Rurik expedition of 1815–1818.