The Dytiscidae – based on the Greek dytikos (δυτικός), "able to dive" – are the predaceous diving beetles, a family of water beetles. They occur in virtually any freshwater habitat around the world, but a few species live among leaf litter. The adults of most are between 1 and 2.5 cm (0.4–1.0 in) long, though much variation is seen between species. The European Dytiscus latissimus and Brazilian Megadytes ducalis are the largest, reaching up to 4.5 cm (1.8 in) and 4.75 cm (1.9 in) respectively. In contrast, the smallest is likely the Australian Limbodessus atypicali of subterranean waters, which only is about 0.9 mm (0.035 in) long. Most are dark brown, blackish, or dark olive in color with golden highlights in some subfamilies. The larvae are commonly known as water tigers due to their voracious appetite. They have short, but sharp mandibles and immediately upon biting, they deliver digestive enzymes into prey to suck their liquefied remains. The family includes more than 4,000 described species in numerous genera.
Hoperius is a genus of predaceous diving beetles in the family Dytiscidae. This genus has a single species, Hoperius planatus. It is found in the United States east of the Rocky Mountains.
Barretthydrus is a genus of beetles in the family Dytiscidae, first described in 1927 by Arthur Mills Lea. The type species is Barretthydrus geminatus.
Copelatus tibialis is a species of diving beetle. It is part of the genus Copelatus of the subfamily Copelatinae in the family Dytiscidae.
Rhantus taprobanicus, is a species of predaceous diving beetle found in India, Nepal, Pakistan and Sri Lanka.
Hydaticus luczonicus, is a species of predaceous diving beetle found in India, Indonesia, Philippines, Sri Lanka, Thailand and Vietnam.
Hyphydrus intermixtus, is a species of predaceous diving beetle found in India and Sri Lanka.
Laccophilus flexuosus, is a species of predaceous diving beetle found in India, Bangladesh, Myanmar, Nepal, Pakistan, Sri Lanka, Cambodia, China, Hong Kong, Indonesia, Iran, Iraq, Japan, Taiwan, Cambodia, Laos and Vietnam.
Clypeodytes bufo, is a species of predaceous diving beetle found in India, Bangladesh, Myanmar, Sri Lanka, China, and Vietnam.
Cybister cardoni, is a species of predaceous diving beetle found in India, Bangladesh, Myanmar, Pakistan, and Sri Lanka.
Cybister dejeanii, is a species of predaceous diving beetle found in India and Sri Lanka.
Cybister prolixus, is a species of predaceous diving beetle found in Sri Lanka.
Cybister sugillatus, is a species of predaceous diving beetle found in India, Sri Lanka, Afghanistan, Bhutan, Myanmar, Nepal, Pakistan, China, Indonesia, Japan, and Philippines.
Cybister ventralis, is a species of predaceous diving beetle found in India, Bangladesh, Myanmar, Pakistan, Sri Lanka and China.
Hydrovatus seminarius, is a species of predaceous diving beetle found in India, Bangladesh, Bhutan, Myanmar, Nepal, Pakistan, Sri Lanka, China, Indonesia, Japan, Laos, Malaysia, Taiwan, Thailand, Vietnam and Australian region.
Pseuduvarus vitticollis, is a species of predaceous diving beetle found in India, Nepal, Pakistan, Sri Lanka, China, Madagascar, Malaysia, Taiwan and African region.
Batrachomatus nannup is a species of diving beetle in the family, Dytiscidae, first described as Allomatus nannup in 1978 by Chris H.S. Watts. The holotype was collected in Bridgetown, Western Australia. In a generic revision in 2013, Lars Hendrich and Michael Balke synonymised AllomatusMouchamps, 1964 with Batrachomatus Clark, 1863, thus changing the species name.
Antiporus hollingsworthi is a species of water beetle in the Scirtidae family, first described in 1997 by Chris Watts.
Barretthydrus geminatus is a species of diving beetle in the family, Dytiscidae, first described in 1927 by Arthur Mills Lea.
Barretthydrus stepheni is a species of freshwater diving beetle in the family, Dytiscidae, first described in 1978 by Chris H.S.Watts. The species has been found in New South Wales.
