Halobates life history


The genus Halobates contains over 40 species, 5 of which are pelagic and live on the surface of the open ocean. Like other gerrids, the sea skaters are hemimetabolous and have a life cycle consisting of the egg, 5 nymphal instars, and the adult. The adults are sexually dimorphic with the female usually being the larger of the sexes.

Food and feeding

Like all water strider (Geridae) species, Halobates are predaceous. They typically feed by liquefying the muscles and the internal organs of their prey. The diet of the open ocean species is not fully known. They have been observed feeding on zooplankton, dead jellyfish, fish eggs and larval fish trapped on the ocean surface. They have never been observed breaking the water surface to feed: they do not dive.


Although they spend their entire lives on the ocean, Halobates requires floating objects on which to place their eggs. The objects include sea bird feathers, floating seashells, pieces of wood, plastic and tar-lumps. Often, oviposition sites are limited, leading to large numbers of eggs being crowded onto small objects.

The eggs are oval in shape and rather large (~1 mm x 0.2 mm) compared to the body size of the female (~5 mm). Females produce between 10 and 20 matured eggs at any one time.


Photos of Marine Skater Eggs
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Eggs on tailfeathers of a dead sea bird

Eggs on a floating Spirulla shell


Halobates are found around the world near the equator and can occur in large numbers. See their distribution

Move closer to shore in search of reliable oviposition sites.