Dytiscidae

Definition

A large family of predaceous diving beetles (order Coleoptera, suborder Adephaga) comprising more than 4,000 described species in numerous genera. Adults are streamlined, oval to elongate, and strongly adapted to aquatic life with hind legs modified as flattened, fringed paddles for swimming. They occur in virtually all freshwater habitats globally, with a few species in moist terrestrial microhabitats. Larvae, known as water tigers, are elongate, active predators with prominent, sickle-shaped mandibles used to inject digestive enzymes and consume liquefied prey tissues. The family includes subfamilies Agabinae, Colymbetinae, Copelatinae, Coptotominae, Dytiscinae, Hydrodytinae, Hydroporinae, Laccophilinae, Lancetinae, and Matinae, plus extinct groups †Liadytiscinae and †Palaeogyrininae.

Etymology

From the genus Dytiscus (Greek δυτικός, dutikós, "able to dive") + Latin family suffix -idae

Example

Dytiscus latissimus, one of the largest extant species at up to 4.5 cm, and the minute subterranean Limbodessus atypicali (~0.9 mm) represent the extreme size range within Dytiscidae.

Synonyms

• Predaceous diving beetles

Related Terms

• Coleoptera
• Adephaga
• Dytiscus
• water tiger
• hydrophilid
• gyrinid
• Coptotominae
• Hydroporinae
• elytron
• metathoracic leg

Usage Notes

Always capitalized as a family-group name. The common name "predaceous diving beetles" distinguishes Dytiscidae from other aquatic beetle families such as Gyrinidae (whirligig beetles) and Hydrophilidae (water scavenger beetles), which differ in antennal structure, ventral surface sculpture, and larval morphology. Adults of most species are capable of flight and disperse between water bodies. The family is monophyletic and constitutes the dominant lineage of predatory aquatic beetles in most freshwater ecosystems.