ABSTRACT

Among the million or so insect species known, only a few thousand are found in marine habitats. The genus

Halobates

is almost exclusively marine and is unique in having the only known species to live in the open ocean. Of the 46

Halobates

species described, only five are completely oceanic in habitat, with the majority of species living in coastal areas associated with mangroves or other marine plants. This review presents a brief historical account of the genus and provides information on various aspects of its life history, ecology, special adaptations, distribution, and biogeography. Distribution maps of the five oceanic species as well as several of the more widely distributed coastal species have been updated. The phylogeny and evolution of

Halobates

based on morphology and recent molecular data are also discussed. A key to all known species of

Halobates

and related genera and a checklist of all species and their distributions are included as appendices.