A water beetle is a generalized name for any beetle that is adapted to living in water at any point in its life cycle. Most water beetles can only live in

fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

, with a few

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

species that live in the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

or littoral zone. There are approximately 2000 species of true water beetles native to lands throughout the world. Many water beetles carry an air bubble, called the elytra cavity, underneath their abdomens, which provides an air supply, and prevents water from getting into the

spiracle Spiracle or spiraculum may refer to: * Spiracle (arthropods), opening in the exoskeletons of some arthropods * Spiracle (vertebrates), openings on the surface of some vertebrates * Spiraculum, a genus of land snails in family Cyclophoridae Cycl ...

s. Others have the surface of their exoskeleton modified to form a plastron, or "physical gill", which permits direct gas exchange with the water. Some families of water beetles have fringed hind legs adapted for swimming, but most do not. Most families of water beetles have larvae that are also aquatic; many have aquatic larvae and terrestrial adults.

Diet

Water beetles can be either

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

s, predators, or

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

s. Herbivorous beetles eat only aquatic vegetation, such as

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

or leaves. They might also suck juices out the stem of a plant nearby. Scavenger beetles will feed on decomposing organic material that has been deposited. The scavenged material can come from aquatic vegetation, feces, or other small organisms that have died. The

great diving beetle The great diving beetle (''Dytiscus marginalis'') is an aquatic diving beetle native to Europe and northern Asia, and in the UK is common in Wales, much of England and southern Scotland but less common on chalk and in the far north. The great ...

, a predator, feeds on things like worms, tadpoles, and even sometimes small fish.

Species

Families in which all species are aquatic in all life stages include: * Dytiscidae * Gyrinidae (Whirligig beetles) * Haliplidae * Noteridae * Amphizoidae * Hygrobiidae (Squeak beetles) *

Meruidae Meruidae is a family of aquatic beetles in the suborder Adephaga, with only one genus and species, ''Meru phyllisae''. The beetle species was first found in the early 1980s.Paul J. Spangler, Warren E. Steiner JR (2005) A new aquatic beetle fami ...

* Hydroscaphidae (Skiff beetles). Families in which the adults are not necessarily aquatic include: * Hydrophilidae * Lutrochidae (Travertine beetles) * Dryopidae * Elmidae * Eulichadidae * Heteroceridae * Limnichidae * Psephenidae (Water-penny beetles) * Ptilodactylidae * Torridincolidae * Sphaeriusidae

References

Epler, J. H. 1996. Identification manual for the water beetles of Florida (Coleoptera: Dryopidae, Dytiscidae, Elmidae, Gyrinidae, Haliplidae, Hydraenidae, Hydrophilidae, Noteridae, Psephenidae, Ptilodactylidae, Scirtidae). (PDF, 9.0 MB)
{{DEFAULTSORT:Water Beetle Beetles by adaptation Aquatic insects Insect common names

Diet

Species

See also

References