Freshwater
Guides
Abedus immaculatus
Abedus immaculatus is a species of giant water bug in the family Belostomatidae. It is the only Abedus species found in the eastern United States, with a range extending throughout Florida north into Georgia and west along the Gulf Coast to Mississippi. Adults measure 13–14 mm in length, making them the smallest species in the genus Abedus and the smallest belostomatid in the United States. The species is the sole member of the subgenus Microabedus. It is locally common in parts of the Everglades, where it occurs in shorter hydroperiod sites.
giant-water-bugaquatic-insectfreshwaterwetlandEvergladesendemiceastern-United-Statessmallest-belostomatid-USAmale-parental-careBelostomatidaeHemipteraMicroabedushydroperiodFloridaGeorgiaMississippiGulf-CoastThomas-Say1832Abedus-cantrallisynonymywater-bugtrue-bugNepomorphaHeteropteraInsectaArthropodaAnimaliaAblabesmyia
Banded-leg Tanypods
Ablabesmyia is a genus of non-biting midges in the bloodworm family Chironomidae, comprising approximately 85 species distributed across multiple continents. Larvae are aquatic and frequently associated with aquatic vegetation, macrophytes, or detrital substrates in freshwater habitats. The genus is divided into four subgenera, with species documented from Europe, Asia, the Americas, and other regions. Adults are typically collected using light traps.
Ablabesmyia annulata
Ablabesmyia annulata is a species of non-biting midge in the family Chironomidae, originally described by Thomas Say in 1823 as Tanypus annulata. The species occurs in the Nearctic region, with documented populations in Canadian freshwater lakes including Lake Winnipeg, Manitoba, and Marion Lake, British Columbia. Like other members of the genus, it has an aquatic larval stage with instar separation approximately following Dyar's rule. The immatures and males have been formally redescribed and illustrated in taxonomic literature.
Ablabesmyia cinctipes
Ablabesmyia cinctipes is a species of non-biting midge in the family Chironomidae, order Diptera. The species was described by Johannsen in 1946. Chironomidae is a large family of aquatic insects whose larvae inhabit diverse freshwater environments. Adults are generally short-lived and do not feed.
Ablabesmyia mallochi
Ablabesmyia mallochi is a non-biting midge species in the family Chironomidae. The immature stages and males were redescribed and illustrated in a 2011 revision of Canadian Ablabesmyia. It belongs to the subgenus Ablabesmyia (Ablabesmyia).
Acanthocyclops
Acanthocyclops is a genus of freshwater copepod crustaceans in the family Cyclopidae, originally described by Friedrich Kiefer in 1927 as a subgenus of Cyclops. Species within this genus inhabit diverse aquatic environments ranging from temporary ponds to large permanent lakes. The genus has been validated through ecological studies demonstrating distinct habitat preferences and life history strategies among closely related species.
Acentria
watermilfoil moth, water veneer
Acentria is a monotypic moth genus in the family Crambidae containing a single species, Acentria ephemerella. The genus is notable for extreme sexual dimorphism in wing development and for having the only known fully aquatic adult female moths. Most females are flightless with rudimentary wings and spend their entire lives underwater, while males are fully winged and terrestrial. The species is native to Europe and has been introduced to North America.
Acentropini
China-mark moths
Acentropini is a tribe of aquatic moths within the family Crambidae, commonly known as china-mark moths. Adults are small to medium-sized moths with wingspans typically ranging from 15–35 mm. The tribe is distinguished by larvae that are fully aquatic, breathing through gills and feeding on submerged aquatic plants. These moths are found across temperate and tropical regions worldwide, with highest diversity in the Old World tropics.
Acilius abbreviatus
Abbreviated Predaceous Diving Beetle
Acilius abbreviatus is a predaceous diving beetle in the family Dytiscidae. It is found in North America, with records from Alberta and British Columbia in Canada. As a member of the genus Acilius, it is an aquatic predator inhabiting freshwater environments.
Acroneuriinae
Acroneuriinae is a subfamily of stoneflies within the family Perlidae, comprising approximately 32 genera and 520 described species. Members are aquatic insects whose larvae inhabit freshwater environments. The subfamily has been the subject of recent mitogenomic research, including the first documented gene rearrangements in the order Plecoptera.
Aegidae
aegid isopods
Aegidae is a family of marine and freshwater isopod crustaceans characterized by temporary parasitic relationships with fish hosts. Adults attach to hosts to feed on blood or tissue, then detach to digest meals. The family is distinguished from related Cirolanidae by having only three pairs of hook-like pereiopods rather than seven. Members occur in diverse aquatic habitats from shallow coastal waters to deep ocean environments, with some species documented at depths exceeding 2000 meters.
Aeshna
Hawkers, Mosaic Darners
Aeshna is a genus of large dragonflies in the family Aeshnidae, commonly known as hawkers in the Old World and mosaic darners in North America. The genus name was coined by Danish entomologist Johan Christian Fabricius in 1775, possibly from a printer's error in spelling the Greek 'Aechma' (spear). Species in this genus are characterized by their relatively large size, brown thoraces and abdomens with distinctive blue, yellow, or green markings. The genus has undergone significant taxonomic revision, with many Neotropical and other species reclassified into separate genera such as Rhionaeschna, Afroaeschna, and others based on phylogenetic studies.
Aeshna constricta
Lance-tipped Darner
Aeshna constricta, commonly known as the Lance-tipped Darner, is a large dragonfly species in the family Aeshnidae. It is distributed across North America and holds a conservation status of Least Concern with a stable population. The species is one of approximately 30 species in the diverse genus Aeshna, which are among the largest and most powerful fliers in the dragonfly order.
Aeshna palmata
Paddle-tailed Darner
Aeshna palmata, commonly known as the Paddle-tailed Darner, is a species of dragonfly in the family Aeshnidae. It is widely distributed across western Canada and the western United States. The species is named for its distinctive paddle-shaped cerci (appendages at the tip of the abdomen). It inhabits lakes, ponds, and slow-moving streams, typically with dense vegetation along the shorelines. The species was first scientifically described by Hermann Hagen in 1856.
Agabetes
Agabetes is a small genus of diving beetles (family Dytiscidae) in the subfamily Laccophilinae. The genus contains two described species: Agabetes acuductus, described from North America in 1828, and Agabetes svetlanae, described from the Palearctic region in 1989. The genus is the type genus of the tribe Agabetini. Members are aquatic beetles inhabiting freshwater environments.
Agabinus
Agabinus is a genus of predaceous diving beetles (family Dytiscidae) established by Crotch in 1873. The genus contains two described species: Agabinus glabrellus and Agabinus sculpturellus. Members are found in North America and are classified within the subfamily Agabinae.
Agabus antennatus
Agabus antennatus is a species of predaceous diving beetle in the family Dytiscidae, first described by Leech in 1939. It is found in North America, with records from Alberta and British Columbia in Canada. As a member of the genus Agabus, it is an aquatic predator inhabiting freshwater environments.
Agabus canadensis
Agabus canadensis is a predaceous diving beetle in the family Dytiscidae, described by Fall in 1922. It is found in North America, with records from Canada (Alberta, British Columbia) and the United States. As a member of the genus Agabus, it is an aquatic predator inhabiting freshwater environments.
Agabus crassipes
Agabus crassipes is a diving beetle species in the family Dytiscidae, described by Fall in 1922. It is native to North America, with records from western Canada including Alberta and British Columbia. As a member of the genus Agabus, it is an aquatic predator inhabiting freshwater environments. The specific epithet 'crassipes' refers to its stout or thick legs.
Agabus punctulatus
Agabus punctulatus is a predaceous diving beetle in the family Dytiscidae. It inhabits freshwater environments and is distributed across North America, with records from western Canada including Alberta and British Columbia. As a member of the genus Agabus, it is part of a diverse group of aquatic beetles adapted to life in ponds, lakes, and slow-moving waters.
Agabus strigulosus
Agabus strigulosus is a species of predaceous diving beetle in the family Dytiscidae. It was first described by Crotch in 1873 under the basionym Gaurodytes strigulosus. The species is found in North America, with records from Alberta and British Columbia in Canada.
Agabus taeniolatus
Agabus taeniolatus is a species of predaceous diving beetle in the family Dytiscidae. It belongs to the large genus Agabus, which contains numerous aquatic beetle species found primarily in the Holarctic region. This species is documented from North America and shares the general ecological characteristics of the genus as an aquatic predator in freshwater habitats.
Agabus verisimilis
Agabus verisimilis is a species of predaceous diving beetle in the family Dytiscidae. It belongs to the large genus Agabus, which contains numerous similar-looking species primarily associated with freshwater habitats. The specific epithet "verisimilis" (meaning "very similar") likely refers to its close resemblance to other Agabus species. Information on this species is limited in published literature.
Agapetus
Agapetus caddisflies
Agapetus is a genus of caddisflies in the family Glossosomatidae, commonly known as saddle-case makers. Larvae construct portable, dome-shaped cases from sand grains and are found in lotic freshwater habitats. The genus has a global distribution with species documented across Europe, Asia, Australia, and North America. Life cycles vary among species, ranging from univoltine to trivoltine patterns depending on geographic location and environmental conditions.
Agnetina flavescens
Midwestern Stone
Agnetina flavescens, commonly known as the midwestern stone, is a stonefly species in the family Perlidae. It is native to North America and has been documented in several midwestern and southeastern US states. As a member of the common stoneflies, it inhabits freshwater systems where its aquatic nymphs develop. The species was originally described as Perla flavescens by Walsh in 1862 before being transferred to the genus Agnetina.
Allocapnia vivipara
Shortwing Snowfly, short-wing snowfly
Allocapnia vivipara, commonly known as the shortwing snowfly, is a species of small winter stonefly in the family Capniidae. It is native to North America and has been recorded from multiple states in the central United States. The species was originally described as Capnella vivipara by Claassen in 1924 before being transferred to Allocapnia. As a winter stonefly, it belongs to a group adapted to cold-season activity.
Ambrysus occidentalis
Ambrysus occidentalis is a species of creeping water bug in the family Naucoridae, described by La Rivers in 1951. It is distributed across Central America and North America. As a member of Naucoridae, it is an aquatic true bug adapted to life in freshwater environments. A study on its mating behavior has been published in the American Midland Naturalist, indicating research interest in its reproductive biology.
Ameletus
Upland Summer Mayfly (A. inopinatus)
Ameletus is a genus of mayflies (Ephemeroptera) and the type genus of the family Ameletidae, circumscribed by Rev. A. E. Eaton in 1885. The genus is speciose, with approximately 30 bisexual species recognized in North America and additional species in Europe and Asia. Ameletus species occur in cold-water streams from small headwater brooks to larger rivers, with greatest diversity in mountainous regions of western North America. The genus includes A. inopinatus, the only predominantly montane mayfly species in the UK and a noted climate change indicator species.
Ameletus browni
purple marram
Ameletus browni is a mayfly species in the family Ameletidae, commonly known as the "purple marram." It was described by McDunnough in 1933 based on nymphal specimens collected in southern British Columbia. The species belongs to the Nearctic fauna and is found in northeastern North America, including Canada and the northeastern United States. Like other members of the genus Ameletus, it is associated with cool, clean freshwater habitats.
Ameletus ludens
Ameletus ludens is a species of combmouthed minnow mayfly in the family Ameletidae, described by Needham in 1905. It belongs to the order Ephemeroptera, a group of aquatic insects known for their brief adult lifespans. The species is found in North America, though specific details about its ecology and life history remain limited in available sources.
Ameletus similior
Ameletus similior is a mayfly species (Ephemeroptera: Ameletidae) described by McDunnough in 1928. It occurs in western North America from southern British Columbia to Alberta, with identification keys also applicable to Saskatchewan, Montana, and northern Idaho and Washington. The species was previously known as A. monta, which has been synonymized with A. similior. Adult males have practically clear hyaline wings and differ from the similar A. alticolus in genitalic characters.
Ameletus subnotatus
combmouthed minnow mayfly
Ameletus subnotatus is a species of combmouthed minnow mayfly in the family Ameletidae. It is one of 13 bisexual Ameletus species documented in Alberta, Canada, where it occurs across virtually all hydrographic basins from small headwater streams to large rivers. The species is found throughout Canada and extends into the northern and southwestern United States.
Ameletus validus
combmouthed minnow mayfly
Ameletus validus is a species of mayfly in the family Ameletidae, first described by McDunnough in 1923. It is one of approximately 30 bisexual species recognized in the genus Ameletus across North America. The species occurs in running waters from small headwater streams to large rivers, with documented populations in western North America including Alberta, British Columbia, and the western United States. Taxonomic work has clarified that adult wings are lightly and evenly suffused with brownish-amber, not speckled as previously miskeyed.
Ameletus velox
Ameletus velox is a North American mayfly species described by Dodds in 1923. It belongs to the family Ameletidae, a group of predatory mayflies known for their distinctive larval morphology and behavior. The species is part of the Nearctic fauna with documented presence in North America. As with other Ameletus species, it likely inhabits cool freshwater streams, though specific ecological details for this species remain limited in available literature.
Amiocentrus
humpless casemaker caddisflies
Amiocentrus is a genus of caddisflies (order Trichoptera) in the family Brachycentridae, commonly referred to as humpless casemaker caddisflies. The genus was established by Ross in 1938 and contains at least two described species: Amiocentrus aspilus and Amiocentrus tessellatum. Members of this genus are aquatic insects whose larvae construct portable cases from plant material.
Amiocentrus aspilus
humpless casemaker caddisfly
Amiocentrus aspilus is a species of caddisfly in the family Brachycentridae, commonly referred to as the humpless casemaker caddisflies. It is known from North America and belongs to a genus whose larvae construct distinctive portable cases using plant material. The species was described by Ross in 1938. Like other brachycentrids, it is associated with freshwater habitats.
Anacaenini
Anacaenini is a tribe of small aquatic beetles in the family Hydrophilidae, containing 256 species across 6 genera. Members inhabit freshwater environments and are characterized by their compact body form and aquatic adaptations. The tribe was established by Hansen in 1991 and is classified within the subfamily Hydrophilinae.
Anisocentropus
Anisocentropus is a cosmopolitan genus of caddisflies (Trichoptera: Calamoceratidae) comprising over 60 described species distributed across Oriental, Australasian, Afrotropical, Neotropical, Nearctic, and East Palearctic regions. Larvae are case-building detritivores that construct portable shelters from leaf pieces or wood fragments, inhabiting both lotic and lentic freshwater environments depending on species. The genus exhibits notable variation in habitat preference, with some species strictly adapted to standing water while others occupy running water or both environments.
Anisogammaridae
Anisogammaridae is a family of small benthic amphipod crustaceans endemic to the northern Pacific Rim. The family includes freshwater, estuarine, and marine species distributed across the Japanese Archipelago, Korean Peninsula, Chinese mainland, and Pacific coast of North America. Members exhibit diverse life history strategies including annual winter-breeding cycles in temperate freshwater habitats and bivoltine patterns in estuarine environments. The family is notable for containing the most diverse group of Japanese freshwater amphipods (genus Jesogammarus) and species of conservation concern due to restricted ranges and habitat vulnerability.
Annulipalpia
fixed-retreat makers
Annulipalpia is a suborder of Trichoptera (caddisflies) distinguished by the flexible, multi-ringed terminal segment of the adult maxillary palps. Larvae are aquatic and construct fixed retreats—stationary structures to which they remain attached—rather than portable cases. Some families build simple silken tubes anchored to the substrate, while others spin silken nets for filter feeding. The suborder includes families such as Psychomyiidae, Ecnomidae, Xiphocentronidae, Polycentropodidae, and Dipseudopsidae.
Anomopoda
water fleas
Anomopoda is a group of small aquatic crustaceans commonly known as water fleas, classified within Branchiopoda and Diplostraca. The group includes several families of ecological and scientific importance, with some species widely used as model organisms in evolutionary biology, ecology, and toxicology. Anomopods exhibit remarkable reproductive flexibility, alternating between parthenogenetic and sexual reproduction. They occupy diverse freshwater habitats across the globe and serve as critical components of aquatic food webs.
Anthopotamus myops
hacklegilled burrower mayfly
Anthopotamus myops is a species of hacklegilled burrower mayfly in the family Potamanthidae. It inhabits freshwater environments in southeastern Canada and the eastern United States. As a member of the order Ephemeroptera, it has a short adult lifespan and aquatic nymphal stages.
Anticheta melanosoma
Anticheta melanosoma is a species of marsh fly in the family Sciomyzidae, described by Melander in 1920. The genus Anticheta belongs to the tribe Tetanocerini, a group known for larvae that are predators or parasitoids of freshwater snails. The specific epithet "melanosoma" refers to the dark body coloration characteristic of this species. Records indicate this species occurs in the northeastern United States, particularly Vermont.
Apataniidae
Early Smoky Wing Sedges
Apataniidae is a family of caddisflies (Trichoptera) commonly known as early smoky wing sedges. The family contains approximately 18 genera and at least 180 described species. Members are primarily Holarctic in distribution, with notable diversity in Europe, Asia, and North America. Larvae are aquatic and construct portable cases from mineral particles.
Apsectrotanypus johnsoni
Apsectrotanypus johnsoni is a species of non-biting midge in the family Chironomidae, subfamily Tanypodinae. It was described by Coquillett in 1901. As a member of the tribe Macropelopini, it belongs to a group of predatory midges whose larvae inhabit aquatic environments. The species is documented in the Catalogue of Life and GBIF as an accepted taxon, with 25 observations recorded on iNaturalist.
Aquarius remigis
common water strider
Aquarius remigis is a predatory aquatic bug known as the common water strider. Formerly classified as Gerris remigis, the species was reclassified in 1990 when Aquarius was elevated to generic rank. It inhabits freshwater surfaces across North America, with highest prevalence in the midwestern United States. Populations exhibit geographic variation in life history, with northern populations typically univoltine and southern populations showing greater plasticity in voltinism.
Archilestes grandis
Great Spreadwing
Archilestes grandis, commonly known as the Great Spreadwing, is a large damselfly in the family Lestidae. It is one of the largest damselfly species in North America, often mistaken for a dragonfly due to its substantial size. The species is widespread across much of the United States and extends into Mexico and Central America. When startled, individuals frequently return to the same perch or one nearby.
Arctocorisa sutilis
Arctocorisa sutilis is a species of water boatman in the family Corixidae, first described by Uhler in 1876. It belongs to a genus of aquatic true bugs found in freshwater habitats. The species is recorded from North America, particularly in the Nearctic region excluding Beringia. Like other corixids, it is an aquatic insect adapted to life in ponds, lakes, and slow-moving waters. Very limited published information exists on its specific biology.
Arcynopterygini
springflies
Arcynopterygini is a tribe of springflies (Plecoptera) within the family Perlodidae. The tribe contains approximately 11 genera and more than 30 described species. Members are distributed across the Northern Hemisphere, with genera found in North America, Europe, and Asia. The tribe was established by Ricker & Scudder in 1975.
Argia bipunctulata
seepage dancer
Argia bipunctulata, commonly known as the seepage dancer, is a species of narrow-winged damselfly in the family Coenagrionidae. It is native to North America and holds a conservation status of Least Concern (LC) according to the IUCN, with a stable population and no immediate threats to its survival. As a member of the genus Argia—the largest genus in the subfamily Argiinae—this species exhibits the characteristic "dancing" flight pattern typical of its congeners.