The whirligig beetles are water beetles, comprising the family Gyrinidae that usually swim on the surface of the water if undisturbed, though they swim underwater when threatened. They get their common name from their habit of swimming rapidly in circles when alarmed, and are also notable for their divided eyes which are believed to enable them to see both above and below water. The family includes some 700 extant species worldwide, in 15 genera, plus a few fossil species. Most species are very similar in general appearance, though they vary in size from perhaps 3 mm to 18 mm in length. They tend to be flattened and rounded in cross section, in plain view as seen from above, and in longitudinal section. In fact their shape is a good first approximation to an ellipsoid, with legs and other appendages fitting closely into a streamlined surface. Whirligig beetles belong to the beetle suborder Adephaga, which also includes ground beetles and diving beetles.
The Haliplidae are a family of water beetles that swim using an alternating motion of the legs. They are therefore clumsy in water, and prefer to get around by crawling. The family consists of about 200 species in 5 genera, distributed wherever there is freshwater habitat; it is the only extant member of superfamily Haliploidea. They are also known as crawling water beetles or haliplids.
The Adephaga are a suborder of beetles, and with more than 40,000 recorded species in 10 families, the second-largest of the four beetle suborders. Members of this suborder are collectively known as adephagans. The largest family is Carabidae which comprises most of the suborder with over 40,000 species. Adephaga also includes a variety of aquatic beetles, such as predaceous diving beetles and whirligig beetles.
Hydrophilidae, also known colloquially as water scavenger beetles, is a family of beetles. Aquatic hydrophilids are notable for their long maxillary palps, which are longer than their antennae. Several of the former subfamilies of Hydrophilidae have recently been removed and elevated to family rank; Epimetopidae, Georissidae, Helophoridae, Hydrochidae, and Spercheidae. While the majority of hydrophilids are aquatic, around a third of described species are terrestrial, mostly belonging to the subfamily Sphaeridiinae.
Byrrhoidea is a superfamily of beetles belonging to Elateriformia that includes several families which are either aquatic or associated with a semi-aquatic habitat. Other than the superfamily Hydrophiloidea, most of the remaining Polyphagan beetles which are aquatic are in this superfamily.
Thermonectus marmoratus is a relatively colorful North American species of diving beetle known by the common names sunburst diving beetle and yellow-spotted diving beetle. The behavior of this diving beetle has been compared to a scuba diver, since it carries with it a bubble of air as it dives down into the water. Its aquatic larval stage was the first ever recorded use of bifocals in the animal world. The beetle uses in its principal eyes two retinas and two distinct focal planes that are substantially separated, in the manner of bifocals to switch their vision from up-close to distance, for easy and efficient capture of their prey.
Acilius sulcatus is a species of water beetle in the family Dytiscidae. It is fairly large, with color variation shown throughout its range. Typically it is yellow and black.
Scirtidae is a family of beetles (Coleoptera). These beetles are commonly referred to as marsh beetles, as the larvae are typically associated with stagnant water, but can be found in flowing water. Adults prefer decomposing plant material near the water's edge. More than an estimated 600 species are known worldwide, distributed among at least 60 genera.
Hydrophilus acuminatus, common name dark diving beetle, is a species of water scavenger beetles belonging to the family Hydrophilidae.
Buenoa marki is a species of backswimmer in the family Notonectidae. It is only known from the solution holes near the Pinelands Trail in Everglades National Park, Florida, although it may occur elsewhere.
Gymnochthebius seminole is a species of tiny beetle in the family Hydraenidae. It is known only from a single adult male specimen collected in a "sawgrass-mangrove area" along the Snake Bight Trail north of Flamingo in Everglades National Park, Florida on 27 August 1965. This specimen was 1.20 millimetres (0.047 in) long, with a relatively robust body. It is most similar to G. oppositus. The species is named for the Seminole people of Florida.
Regimbartia attenuata, commonly known as Japanese water scavenger beetle, is a species of water scavenger beetle widely distributed in the Old World, from northern Australia and Japan westward to the countries of Arabian Peninsula, including Oman and Yemen. It is the only species of the genus occurring in the Arabian Peninsula.
Sphaeridium quinquemaculatum, is a species of water scavenger beetle found in India, China, Indonesia, Nepal, Sri Lanka, Laos, Thailand and the Philippines.
Hydrovatus castaneus, is a species of predaceous diving beetle found in India, Myanmar, Indonesia, Sri Lanka, Bangladesh, and China.
Hydrovatus bonvouloiri, is a species of predaceous diving beetle found in India, Sri Lanka, Malayasia, Myanmar, China, Japan, Vietnam, Formosa, Indonesia, Thailand, Laos, Taiwan, and Philippines.
Hydrovatus acuminatus, is a species of predaceous diving beetle found in Oriental and African regions.
Hydroglyphus flammulatus, is a species of predaceous diving beetle found in India, Sri Lanka, Pakistan, Thailand, Cambodia, China, Taiwan, Korea, Myanmar, Bangladesh, Indonesia, Vietnam, and Nepal.
Hydaticus vittatus, is a species of predaceous diving beetle found in India, Pakistan, Sri Lanka, Nepal, Bangladesh, Bhutan, Myanmar, China, Japan, Taiwan, Thailand, Cambodia, Laos, Vietnam, Malaysia and Indonesia.
Cybister tripunctatus, is a species of predaceous diving beetle found in India, Andaman & Nicobar Islands, Sri Lanka, Afghanistan, Bangladesh, Myanmar, Nepal, Pakistan, Bhutan, China, Cyprus, Iran, Iraq, Japan, Kyrgyzstan, Mongolia, Russia, Syria, Tajikistan, Turkmenistan, Italy, Turkey, Uzbekistan and Europe.
Hydrovatus picipennis, is a species of predaceous diving beetle found in India, Sri Lanka, Indonesia, Philippines, China and Thailand.
