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.
Rhantus is a genus of beetle in family Dytiscidae. There are about 100 species distributed worldwide. They often live in pools and marshy habitat types. Several species have colonized oceanic islands and become endemics.
Laccophilus is a genus of water beetle found in nearly every temperate or tropical region in the world including but not limited to Europe, the Near East, the Nearctic, North Africa and the Oriental region. It contains the following species:
Hyphydrus is a genus of diving beetle native to the Palearctic, the Afro-tropical region, the Near East, North Africa. It contains the following species:
Hydroporus is a genus of water beetles native to the Palearctic, the Nearctic, the Near East, and North Africa. It contains the following species:
Hydaticus is a genus of predatory water beetle belonging to the family Dytiscidae. Hydaticus can be found throughout most of the world. There are 150 described species and 12 subspecies in two subgenera in the genus Hydaticus.
Cybister, is a genus of beetle in family Dytiscidae. They are found in much of the world, including all continents except Antarctica. As of 2021 there are 96 species and 9 additional subspecies among four subgenera in the genus.
Platynectes is a genus of beetles in the family Dytiscidae, containing the following species:
Prodaticus is a subgenus of beetles of the genus Hydaticus in the family Dytiscidae. These 143 species are in the subgenus Prodaticus:
Clypeodytes is a genus of beetles in the family Dytiscidae, containing the following species:
Hydroglyphus is a genus of beetles in the family Dytiscidae, containing the following species:
Uvarus is a genus of beetles in the family Dytiscidae, containing the following species:
Yola is a genus of beetles in the family Dytiscidae, containing the following species:
Nebrioporus is a genus of beetles in the family Dytiscidae, containing the following species:
Hydrovatus is a genus of water beetles in the family Dytiscidae, containing the following species:
Neptosternus is a genus of beetles in the family Dytiscidae, containing the following species:
Canthydrus is a genus of beetles in the family Noteridae, containing the following species:
Hydrocanthus is a genus of beetles in the family Noteridae, containing the following species:
Exocelina is a genus of beetles in the family Dytiscidae, containing the following species:
