Stream

Guides

  • 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.

  • Basiaeschna janata

    Springtime Darner

    Basiaeschna janata, the Springtime Darner, is a small, bluish dragonfly in the family Aeshnidae. It is the sole member of the monotypic genus Basiaeschna. This species is notable for its early seasonal flight period, appearing in spring when most other darner species have not yet emerged. It is widely distributed across North America.

  • Brachycentridae

    Humpless Casemaker Caddisflies

    Brachycentridae is a family of caddisflies (order Trichoptera) commonly known as humpless casemaker caddisflies. The family contains approximately 100 species across 8 genera and is distributed across North America, Europe, and Asia. Larvae construct portable cases using plant material, rock fragments, or silk, with some species exhibiting specialized filter-feeding behaviors. The family was first described by Georg Ulmer in 1903 as a subfamily of Sericostomatidae before being elevated to family rank.

  • Brachycentrus

    Grannom Caddisflies, Humpless Casemaker Caddisflies

    Brachycentrus is a genus of caddisflies in the family Brachycentridae, commonly known as grannoms or humpless casemaker caddisflies. The genus contains at least 30 described species distributed across North America and Eurasia. Larvae are aquatic filter-feeders that construct portable cases from silk and environmental materials such as sand, small stones, or plant fragments. The genus is ecologically significant as an important prey item for trout and other freshwater fish.

  • Calamoceratidae

    Calamoceratidae is a family of caddisflies comprising approximately 9 genera and at least 120 described species. The family is distributed across tropical and temperate regions worldwide, with notable diversity in the Neotropics. Larvae are aquatic and construct distinctive cases from plant material. The genus Phylloicus is particularly species-rich in the New World, with 66 described species.

  • Chimarra obscura

    fingernet caddisfly

    Chimarra obscura is a species of fingernet caddisfly in the family Philopotamidae, found in North America. The genus Chimarra is characterized by blackish body and wings. This species has been documented from Missouri, specifically from Sam A. Baker State Park in the Ozark Highlands, where it was recorded alongside C. feria and an unidentified Chimarra species. The species was originally described by Walker in 1852.

  • Coptotomus loticus

    Coptotomus loticus is a predaceous diving beetle described by Hilsenhoff in 1980. It belongs to the subfamily Coptotominae within Dytiscidae, a family of aquatic beetles. The species is known from eastern Canada, with records from Ontario and Québec. As a member of Coptotomus, it represents one of the less commonly encountered genera in North American dytiscid fauna.

  • Cordulegastridae

    Spiketails, biddie, flying adder

    Cordulegastridae, commonly known as spiketails, is a family of dragonflies (Anisoptera) distributed across the Holarctic region. The family contains approximately 51 species in three to four genera, including Cordulegaster, Anotogaster, Neallogaster, and the recently restored Thecagaster and Zoraena. Adults are characterized by large black or brown bodies with yellow markings, blue-green eyes that meet at a single point, and a slow flight pattern 30–70 cm above water. Nymphs are specialized ambush predators that conceal themselves in sand or silt substrates of clean, flowing streams.

  • Dicosmoecus

    October Caddisflies

    Dicosmoecus is a genus of caddisflies in the family Limnephilidae, commonly known as October Caddisflies. The genus contains approximately six described species distributed across western North America, from California and Oregon through British Columbia to the Rocky Mountains. Species such as D. gilvipes and D. atripes are among the most intensively studied North American caddisflies due to their large larval size, synchronous autumn emergence, and importance in freshwater ecosystem research and fly-fishing culture.

  • Enallagma exsulans

    Stream Bluet

    Enallagma exsulans, commonly known as the Stream Bluet, is a species of damselfly in the family Coenagrionidae. It is distinguished from many other bluet species by its strong association with flowing water rather than still ponds and lakes. The species ranges across much of eastern and central North America.

  • Ephemerellidae

    Spiny Crawler Mayflies

    Ephemerellidae, commonly known as spiny crawler mayflies, is a family of mayflies (Ephemeroptera) comprising approximately 90 species across 8-14 genera. The family is distributed throughout North America and the UK, with additional records from Europe and Asia. Nymphs inhabit lotic-erosional environments including flowing streams of all sizes, lake shores, and beaches with wave action. They are primarily collector-gatherers and serve as important indicators of water quality due to their sensitivity to pollution.

  • Gomphurus hybridus

    Cocoa Clubtail

    A medium-sized clubtail dragonfly endemic to eastern North America. Adults are active in late spring through mid-summer, with peak emergence typically in June. The species is named for the cocoa-brown coloration of mature males. Larvae develop in streams and rivers, requiring clean, flowing water with sandy or gravelly substrates. Like other gomphids, it is a predator both as aquatic nymph and aerial adult.

  • Helicopsyche borealis

    Spectacled Snail-case Caddisfly

    Helicopsyche borealis is a caddisfly species in the family Helicopsychidae, notable as one of only two Helicopsyche species to colonize temperate North America from a predominantly tropical genus. Larvae construct distinctive spiral, snail-like cases from sand grains cemented with silk. The species inhabits running waters across North America and plays a role as a collector-gatherer and scraper in stream ecosystems. Adults emerge in spring, and the life cycle is univoltine with egg diapause through summer.

  • Limnephilus

    caddisfly

    Limnephilus is the most diverse genus in the family Limnephilidae, containing over 180 described species with broad ecological tolerances and a primarily Holarctic distribution. Species inhabit diverse freshwater habitats including lakes, ponds, slow-moving streams, and high-altitude streams, with some extending to salt marshes and desert environments. Several species are of conservation concern in North America. The genus has been extensively studied as a bioindicator for aquatic pollution and as a model for understanding predator-prey interactions and case-building behavior.

  • Lutrochus laticeps

    travertine beetle

    Lutrochus laticeps is a species of travertine beetle in the family Lutrochidae, first described by Casey in 1893. It was rediscovered in Kansas, USA, representing a significant range extension. The species is associated with freshwater stream habitats in eastern North America.

  • Maccaffertium mediopunctatum mediopunctatum

    Maccaffertium mediopunctatum mediopunctatum is a subspecies of mayfly in the family Heptageniidae. The genus Maccaffertium was established to accommodate species formerly placed in Heptagenia and related genera, distinguished by particular features of the male genitalia and wing venation. This subspecies is part of a group of flatheaded mayflies commonly found in North American streams and rivers. Subimagos (subadults) of this species exhibit the characteristic pale, milky-white coloration and opaque wings typical of the genus, with sexual dimorphism in eye size and abdominal claspers.

  • Meru

    comb-clawed cascade beetles

    Meru is a monotypic genus of minute aquatic beetles in Meruidae, known from Venezuela. Its only described species, M. phyllisae, is less than a millimeter long and was collected at El Tobogán, where streams run over exposed bedrock. Adult and larval anatomy combine unusual characters that have made the genus important in studies of aquatic beetle relationships.

  • Metrobates hesperius

    Metrobates hesperius is a water strider (family Gerridae) distributed across eastern North America and the Caribbean. It belongs to the subfamily Trepobatinae, a group of semiaquatic bugs that inhabit flowing water habitats. The species was described by Uhler in 1871 and includes three recognized subspecies with distinct geographic distributions.

  • Neophylax

    autumn mottled sedges

    Neophylax is a genus of caddisflies commonly known as autumn mottled sedges, containing more than 30 described species. Larvae are aquatic case-builders that construct protective cases using silk and materials gathered from streambeds, including sand, stones, shells, and plant material. The genus exhibits notable life history diversity, with species showing temporal and spatial segregation in stream systems. Adults typically emerge in autumn, giving rise to the common name.

  • Parapoynx maculalis

    polymorphic pondweed moth

    Parapoynx maculalis, commonly known as the polymorphic pondweed moth, is a small aquatic moth in the family Crambidae. It inhabits freshwater environments across eastern North America, from Florida and Texas north to Canada. The species is distinguished by its small size, white forewings with fuscous markings, and fully aquatic larval stage that feeds on submerged plants.

  • Pardosa valens

    Pardosa valens Barnes, 1959 is a wolf spider (family Lycosidae) documented from small mountain streams in southeastern Arizona. It moves over streamside cobbles and across the water surface, and laboratory studies have examined how losing legs affects its movement. Those effects vary with sex and whether the spider is moving on land or water.

  • Rhyacophilidae

    Free-living Caddisflies

    Rhyacophilidae is a family of caddisflies (Trichoptera) commonly known as free-living caddisflies. Larvae are distinctive for not constructing portable cases, instead living freely on substrates in freshwater habitats. Most species are predatory. The family contains over 700 described species, with the genus Rhyacophila alone comprising approximately 500 species distributed primarily across the Northern Hemisphere.

  • Somatochlora

    Striped Emeralds, Striped Emerald Dragonflies

    Somatochlora is a genus of 42 described species of medium-sized dragonflies in the family Corduliidae, distributed across the Northern Hemisphere in Europe, Asia, and North America. Members are characterized by dark bodies with metallic green lustre, brilliant green eyes, and often yellow thoracic or abdominal markings. Species-level identification is challenging and requires examination of male cerci or female subgenital plates. Many species are habitat specialists with restricted distributions, particularly associated with boreal and montane wetland systems.

  • Stenelmis

    riffle beetle

    Stenelmis is the largest and most widespread genus of beetles in the family Elmidae. Members are commonly known as riffle beetles due to their association with fast-flowing stream habitats. The genus contains numerous species distributed across multiple continents, with documented presence in North America, Europe, and the Caucasus region.

  • Stylogomphus albistylus

    Eastern Least Clubtail

    Stylogomphus albistylus, the eastern least clubtail, is a small clubtail dragonfly in the family Gomphidae. It is found in eastern North America, particularly in the Appalachian region and surrounding areas. The species is classified as Least Concern by the IUCN, with a stable population and no immediate threats to its survival.

  • Zaitzevia

    riffle beetles

    Zaitzevia is a genus of riffle beetles (family Elmidae) comprising approximately 19–29 described species, depending on taxonomic treatment. The genus was established by George Charles Champion in 1923 and is named after Russian entomologist Filipp Zaitsev. Species diversity is concentrated in East, Southeast, and Central Asia, with additional representation in North America. Chinese species are particularly well-documented, with multiple new species described from Sichuan, Yunnan, Hunan, Hubei, and Guizhou provinces.