Gerridae is a family of true bugs in the order Hemiptera, commonly known as water striders, water bugs,magic bugs, pond skaters, skaters, skimmers, water scooters, water skaters, water skeeters, water skimmers, water skippers, water spiders, or Jesus bugs. Consistent with the classification of Gerridae as true bugs, gerrids have a mouthpart evolved for piercing and sucking, gerrids distinguish themselves by having the unique ability to walk on water. Gerridae, or water striders, are anatomically built to transfer their weight to be able to run on top of the water’s surface. As a result, one could likely find water striders present in any pond, river, or lake. Scientists have identified over 1,700 species of gerrids, 10% of them being marine.
While 90% of Gerridae are freshwater bugs, it is the oceanic Halobates that make the family quite exceptional among insects. The genus Halobates was first heavily studied between 1822 and 1883 when Buchanan-White collected several different species during the Challenger Expedition. Around this time, Eschscholtz discovered three species of Family Gerridae, Order Hemiptera, raising attention to the species even though little of their biology was known. Since then, the Gerridae have been continuously studied due to their ability to walk on water and unique social characteristics. Small gerrids have frequently been confused with the other semiaquatic bugs, Veliidae. The most consistent characteristic used to separate these two families are internal genitalia differences. Since internal genitalia require specific training and tools to identify, it is almost impossible to tell a member of the Gerridae apart from a member of the Veliidae by external visual cues. One must study their habitat and behaviors to properly differentiate the two without looking at their specific anatomy.
(From Wikipedia, February 2015)