Water-quality
Guides
Acroneuria
common stoneflies
Acroneuria is a genus of large-bodied stoneflies in the family Perlidae, containing more than 30 described species distributed across North America and Asia. Nymphs are predatory and inhabit streams and rivers, where they serve as important bioindicators of water quality. Adults are known for distinctive emergence behaviors, including arboreal emergence in some species. Several species in the genus are experiencing range contractions and population declines due to habitat degradation and climate change.
Cheumatopsyche
Little Sister Sedges
Cheumatopsyche is a large genus of net-spinning caddisflies comprising at least 240 described species. Larvae construct silk capture nets to filter food from flowing water and are important components of freshwater benthic communities. Species exhibit variable life histories including univoltine and multivoltine cycles, with some populations capable of producing additional generations when thermal conditions permit. The genus is widely distributed across multiple continents and serves as a significant bioindicator for water quality assessment.
Chironomidae
non-biting midges, chironomids, lake flies, bay flies, sand flies, muckleheads, muffleheads, Canadian soldiers, American soldiers, blind mosquitoes, chizzywinks, bloodworms (larval stage)
Chironomidae is a large family of non-biting midges with over 10,000 described species globally. Adults are frequently mistaken for mosquitoes due to their similar body shape, but they lack wing scales and piercing mouthparts. The family exhibits remarkable ecological versatility, with larvae inhabiting diverse aquatic and terrestrial environments from Antarctic glaciers to tropical lakes. Males possess distinctive plumose antennae. Larvae of some species contain hemoglobin analogs that produce bright red coloration, earning them the common name 'bloodworms.'
Cladocera
water fleas
Cladocera is a suborder of small crustaceans commonly known as water fleas, ranging from 0.2–6 mm in size. They are found in freshwater environments worldwide, including rivers, lakes, swamps, and temporary pools, with some species inhabiting brackish water, groundwater, and even leaf axils or caves. These organisms play a central role in freshwater food webs as filter-feeders that consume phytoplankton, bacteria, and organic particles, while serving as essential prey for fish fry and predatory insect larvae. Their sensitivity to environmental changes makes them valuable bioindicators for water quality assessment.
Goeldichironomus
Goeldichironomus is a genus of non-biting midges in the family Chironomidae, containing approximately 14 described species. The genus is distributed across the Neotropical and Nearctic regions, with records from Argentina, Brazil, and Colombia. Species in this genus are notable for their short life cycles, tolerance to environmental stress, and colonization of ephemeral aquatic habitats as pioneer species. They serve as important bioindicators in water quality assessments and are widely used in laboratory toxicity studies. The type species Goeldichironomus holoprasinus has been extensively studied in laboratory conditions, completing development from egg to adult in approximately 13 days at 26°C.
Hexagenia
giant mayflies, burrowing mayflies, fishflies
Hexagenia is a genus of large burrowing mayflies in the family Ephemeridae, comprising eight recognized species. Nymphs construct distinctive U-shaped, ventilated burrows in soft aquatic sediments of lakes, streams, and ponds. Adults are notable for their synchronous mass emergences, which can produce swarms dense enough to appear on weather radar. The genus serves as an important bioindicator of water quality due to its intolerance of pollution and anoxia.
Stenonema
Stenonema is a genus of mayflies in the family Heptageniidae. Species within this genus are aquatic insects found in freshwater environments, with nymphs inhabiting both riffle and pool habitats. The genus has been extensively studied in ecological and toxicological research, particularly regarding morphological variation, behavioral responses to environmental cues, and sensitivity to pollutants. Multiple species, including S. modestum, S. tripunctatum, and S. vicarium, serve as bioindicators for water quality assessment.
Trichoptera
Caddisflies
Caddisflies are an order of approximately 14,500 described species of insects with aquatic larvae and terrestrial adults. The order is divided into two principal suborders: Integripalpia, whose larvae construct portable protective cases while foraging, and Annulipalpia, whose larvae build fixed retreats and wait for food to arrive. Caddisflies are widely distributed globally and are recognized as important bioindicators of freshwater ecosystem health due to their sensitivity to water quality changes.