Filter-feeder
Guides
Arctopsyche
Great Gray Spotted Sedges
Arctopsyche is a genus of netspinning caddisflies in the family Hydropsychidae, comprising more than 20 described species. Larvae construct and maintain capture nets throughout the year to filter food from flowing water. The genus exhibits life cycle flexibility, with documented univoltine and semivoltine patterns depending on environmental conditions. Species occur in lotic habitats across the Holarctic region.
Balanus nubilus
giant acorn barnacle
Balanus nubilus is the world's largest barnacle species, reaching up to 15 cm in diameter and 30 cm in height. It possesses the largest known muscle fibers of any barnacle, making it historically significant for muscle physiology research. This northeast Pacific species is a filter feeder that attaches to hard substrates including rocks, pier pilings, and other animals at depths up to 90 meters.
Bosmina
water flea
Bosmina is a genus of small cladoceran crustaceans commonly known as water fleas. Members are distinguished from the related genus Bosminopsis by having antennae that are separated at their bases rather than fused. Bosmina species are filter feeders that consume algae and protozoans approximately 1–3 μm in size, using a dual feeding mechanism involving mesh-like setules on the second and third legs for filtering while the first leg grasps particles. The genus exhibits notable morphological plasticity, particularly in posterior mucrones and anterior antennules, which vary in response to predation pressure. Some Bosmina species have become invasive outside their native ranges, posing threats to aquatic ecosystems.
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.
Brachycentrus americanus
American Grammon
Brachycentrus americanus is a species of humpless casemaker caddisfly in the family Brachycentridae. Larvae construct portable cases and are sensitive to synthetic pyrethroid insecticides, exhibiting case-abandonment behavior upon exposure. The species displays diel periodicity in activity patterns, with predominantly nocturnal filtering behavior. It is most active in July and August in western and midwestern North America.
Brachycentrus occidentalis
humpless casemaker caddisfly
Brachycentrus occidentalis is a species of humpless casemaker caddisfly in the family Brachycentridae. It is a filter-feeding aquatic insect whose larvae construct fixed retreats with silk nets to capture food particles from flowing water. The species has been studied for its behavioral ecology during pupation, including cannibalism and predation pressures, and for its sensitivity to suspended sediments in stream environments.
Branchiopoda
Branchiopods
Branchiopoda is a class of small, primarily freshwater crustaceans unified by the presence of gills on their appendages—giving the group its name from Greek 'bránkhia' (gill) and 'poús' (foot). The class comprises fairy shrimp (Anostraca), tadpole shrimp (Notostraca), clam shrimp (Spinicaudata, Laevicaudata, Cyclestherida), and water fleas (Cladocera/Diplostraca), plus the extinct Devonian Lepidocaris. Most are filter-feeders on plankton and detritus, though notostracans are opportunistic omnivores. Many species inhabit temporary pools and produce desiccation-resistant resting eggs, allowing survival through dry periods.
Cheumatopsyche analis
Cheumatopsyche analis is a species of netspinning caddisfly in the family Hydropsychidae. It belongs to a genus known for constructing fixed capture nets in flowing water to filter food particles. The species has been documented in the Nearctic region, including Hawaii. As a member of the Hydropsychidae, it participates in freshwater food webs as both a filter-feeder larva and a flying adult.
Cheumatopsyche campyla
Cheumatopsyche campyla is a species of net-spinning caddisfly in the family Hydropsychidae, described by Ross in 1938. As a member of this family, it constructs fixed retreats and capture nets to filter food from flowing water. The species is known to occur in North America.
Chirocephalidae
fairy shrimp
Chirocephalidae is the second largest family of fairy shrimp (Anostraca), characterized by a reduced or vestigial maxilla, more than two setae on the fifth endite, divided pre-epipodites, and widely separated seminal vesicles. The family includes nine genera: Artemiopsis, Branchinectella, Chirocephalus, Dexteria (extinct), Eubranchipus, Linderiella, Parartemiopsis, Polyartemia, and Polyartemiella. Former families Linderiellidae and Polyartemiidae are now included within Chirocephalidae. Most species are distributed in the Holarctic region.
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.
Coronula diadema
whale barnacle, humpback whale barnacle
Coronula diadema is a species of whale barnacle that lives exclusively on cetacean hosts, primarily humpback whales (Megaptera novaeangliae). First described by Carl Linnaeus in 1767, this barnacle attaches to whale skin using specialized coring structures and filter-feeds on plankton. The species exhibits simultaneous hermaphroditism and forms mating groups of up to nine individuals. Its crown-like appearance gives rise to both its scientific and common names.
Daphnia
water fleas, water-fleas
Daphnia is a genus of small planktonic crustaceans (0.2–6.0 mm) in the order Anomopoda, commonly called water fleas due to their saltatory swimming style. The genus comprises over 200 species distributed across diverse freshwater habitats worldwide. Daphnia exhibits cyclical parthenogenesis, alternating between asexual and sexual reproduction, and serves as a keystone organism in freshwater food webs. Several species, particularly D. magna and D. pulex, are extensively used as model organisms in ecology, toxicology, and evolutionary biology research.
Daphnia galeata
water flea
Daphnia galeata is a small planktonic crustacean inhabiting freshwater lakes across the Northern Hemisphere. The species exhibits pronounced phenotypic plasticity in response to environmental conditions, particularly food availability and predation risk. Two subspecies are recognized: D. g. galeata in the Old World and D. g. mendotae in North America, with hybrid populations occurring in the lower Great Lakes. It serves as a key model organism for studying predator-induced defenses and life-history evolution in aquatic systems.
Daphniidae
water fleas
Daphniidae is a family of small freshwater crustaceans in the order Anomopoda, commonly known as water fleas. The family contains approximately 121 species across five genera: Ceriodaphnia, Daphnia, Megafenestra, Scapholeberis, and Simocephalus. Daphniidae species are important model organisms in ecology, toxicology, and evolutionary biology, particularly the genus Daphnia. Many species have been accidentally introduced to regions outside their native ranges through human activity.
Dixidae
Meniscus Midges
Dixidae (meniscus midges) are a small family of nematocerous Diptera comprising fewer than 200 species. Adults are small, frail gnats that remain near aquatic habitats and do not feed. Larvae are aquatic filter-feeders that inhabit unpolluted freshwater margins, where they rest in a distinctive U-shaped posture at the water surface film. The family occurs on all continents except Antarctica and has been documented since the Jurassic period.
Dolophilodes dorca
Dolophilodes dorca is a species of caddisfly in the family Philopotamidae. Members of this genus are small, slender caddisflies associated with lotic (flowing water) habitats. The larvae construct silken retreats and capture nets for feeding on fine particulate organic matter. Like other philopotamids, adults are typically nocturnal and are attracted to light.
Emerita
mole crabs, sand fleas, sand crabs, sand fiddlers, sea cicada
Emerita is a genus of small decapod crustaceans commonly known as mole crabs or sand fleas. These animals inhabit the intertidal zone of sandy beaches, where they burrow in the swash zone and use their antennae for filter feeding. The genus belongs to the family Hippidae and is characterized by a compact, oval body adapted for rapid burrowing in shifting sand.
Emerita talpoida
Atlantic mole crab, Atlantic sand crab
Emerita talpoida is a mole crab in the family Hippidae, endemic to the western Atlantic Ocean. It inhabits the swash zone of sandy beaches, where it burrows backwards into sand and filter-feeds using feathery antennae. The species exhibits a circatidal rhythm in activity with a ~12.4 hour period, with smaller crabs distributed higher intertidally than larger ones. Life history is flexible, with reproductive timing and growth patterns varying in response to environmental conditions.
Ephoron leukon
white fly
Ephoron leukon, commonly known as the white fly, is a species of pale burrower mayfly in the family Polymitarcyidae. Nymphs are burrowing and inhabit tubular burrows associated with stones in river rapids, particularly in fine silt deposits. The species undergoes dramatic morphological changes during early nymphal development, including specialized mouthpart modifications for filter feeding and progressive elaboration of abdominal gills.
Eristalinae
Drone Flies and Allies
Eristalinae is a subfamily of hoverflies (Syrphidae) comprising approximately nine tribes and notable for exceptional Batesian mimicry of bees and wasps. Adults are important pollinators, while larvae exhibit the greatest habitat diversity among hoverflies, occupying aquatic environments, decaying organic matter, sap runs, and even wasp nests. The subfamily includes the well-known drone fly (Eristalis tenax), whose larvae—called rat-tailed maggots—possess an extendable posterior breathing siphon.
Eristalis obscura
Dusky Drone Fly
Eristalis obscura, commonly known as the dusky drone fly, is a species of syrphid fly first described by Loew in 1866. It is widespread across northern North America and extends eastward through Europe to Siberia. The species exhibits the characteristic rat-tailed maggot larval form, with aquatic larvae that function as filter-feeders. Like other members of the genus Eristalis, adults are likely bee mimics, though specific documentation of this behavior for E. obscura is limited.
Eurycercus
Eurycercus is a genus of large-bodied cladoceran crustaceans (water fleas) and the sole genus of the monotypic family Eurycercidae. Species reach up to 6 mm in length, making them among the largest anomopods. The genus contains 16 described species distributed across four subgenera, with a primarily Holarctic distribution and some extensions into the Neotropics and Southern Hemisphere. Species occupy littoral zones of freshwater lakes and ponds, often associated with submerged vegetation.
Glyptotendipes paripes
Glyptotendipes paripes is a non-biting midge (Chironomidae) with a univoltine life cycle in temperate regions. Larvae are filter-feeders that inhabit lake and pond sediments, consuming planktonic diatoms and sestonic particles. The species is known from both European and North American populations, with well-studied populations in central Florida lakes and prairie ponds. Larval distribution is strongly influenced by sediment organic content and particle size, with highest densities in fine, organic-rich sediments.
Hydropsyche
Spotted Sedges
Hydropsyche is a large genus of netspinning caddisflies comprising at least 260 described species worldwide. Larvae construct fixed capture nets across flowing water to filter food particles, a behavior that defines the family Hydropsychidae. The genus exhibits substantial diversity in the Aegean region and Mediterranean, with numerous endemic species on Greek islands. Both larvae and adults have been extensively studied for their morphological characteristics, respiratory physiology, and responses to aquatic hypoxia.
Hydropsyche betteni
Common Netspinner
Hydropsyche betteni is a species of netspinning caddisfly in the family Hydropsychidae, described by Ross in 1938. It is one of the most widespread and commonly encountered members of its genus in North America. Like other hydropsychids, the larvae construct fixed capture nets to filter food from flowing water. The species is well-documented in freshwater biomonitoring studies due to its abundance and sensitivity to water quality.
Hydropsyche occidentalis
Hydropsyche occidentalis is a filter-feeding caddisfly species in the family Hydropsychidae, found in lotic (flowing water) streams of North America. It constructs fixed capture nets to filter organic particles from the water column, playing a significant role in stream ecosystem function. The species has been studied for its bioenergetics and contribution to controlling organic transport in streams, where it can comprise a substantial portion of invertebrate biomass in suitable habitats.
Hydropsyche scalaris
Hydropsyche scalaris is a species of net-spinning caddisfly in the family Hydropsychidae, first described by Hagen in 1861. It belongs to one of the largest genera of caddisflies, with larvae that construct fixed retreats and capture nets in flowing water to filter food particles. The species is documented from North America within the Nearctic region.
Hydropsyche slossonae
Hydropsyche slossonae is a caddisfly species in the family Hydropsychidae, known from freshwater lotic habitats in eastern and midwestern North America. The species is univoltine, with adults emerging synchronously from late May through early July. Larvae construct silk capture nets to filter suspended organic matter from flowing water and overwinter as fifth-instar larvae.
Hydropsyche sparna
Hydropsyche sparna is a species of net-spinning caddisfly in the family Hydropsychidae. It has been studied primarily for its behavioral responses to suspended particles and deposited bedload sediment in flowing water environments. The species is currently treated as a synonym of Ceratopsyche sparna in some taxonomic databases. Research on this species has contributed to understanding how filter-feeding aquatic insects modify their foraging behaviors in response to changing environmental conditions.
Hydropsychinae
net-spinning caddisflies
Hydropsychinae is a subfamily of caddisflies (Trichoptera) within the family Hydropsychidae, commonly known as net-spinning caddisflies. Larvae construct fixed capture nets in flowing water to filter food particles. The subfamily is taxonomically diverse, with generic revisions documented in multiple regions including New Zealand and the Americas.
Isonychia campestris
Isonychia campestris is a filter-feeding mayfly species described by McDunnough in 1931. The immature nymphs inhabit lotic aquatic systems where they employ specialized morphological structures to capture suspended particulate matter from the water column. This species has been studied specifically for its filter feeding mechanisms, which involve interception and diffusive deposition of particles smaller than the pore spaces between filtering structures. The species occurs in the Nearctic region of North America.
Lepadidae
Goose Barnacles
A family of pedunculate (stalked) barnacles established by Charles Darwin in 1852, commonly known as goose barnacles. Comprises approximately five genera and over 20 described species. Members are exclusively marine, with worldwide distribution in warm temperate and tropical seas. The family includes the well-known genus Lepas (goose barnacles) and Conchoderma (whale barnacles).
Lepas anserifera
Goose Barnacle
Lepas anserifera is a pedunculate barnacle that attaches to floating substrates including driftwood, ships' hulls, and marine debris. It possesses a capitulum of six white calcareous plates supported by an orange, flexible stalk. The species exhibits rapid growth and early maturation, with individuals reaching reproductive size within approximately two weeks under favorable conditions. As a hermaphroditic filter feeder, it plays a role in marine neustonic communities and has a cosmopolitan distribution in temperate and tropical seas.
Lype diversa
net tube caddisfly
Lype diversa is a species of net tube caddisfly in the family Psychomyiidae, first described by Nathan Banks in 1914. It is a small, inconspicuous caddisfly found in freshwater habitats across North America. Like other members of its family, larvae construct silken capture nets to filter food particles from flowing water. The species is among the least documented in its genus, with sparse occurrence records and limited ecological study.
Macrostemum
Glossy Wing Sedges
Macrostemum is a cosmopolitan genus of net-spinning caddisflies in the family Hydropsychidae, comprising at least 90 described species. Adults are recognized by distinctive dark and light contrasting wing patterns. Larvae construct silken retreats with capture nets to filter fine particulate organic matter from flowing water. The genus is particularly diverse in the Neotropical region, with species documented across Africa, Asia, Madagascar, and the Americas.
Macrostemum carolina
Macrostemum carolina is a net-spinning caddisfly in the family Hydropsychidae. Larvae construct silken catchnets within protective retreats to filter food from flowing water. Multiple retreat-building phenotypes exist within this species, including retreats with water entrance holes at the end of silken tubes, with 180° silken backstops, or flush with the retreat top. Molecular genetic analysis confirms these phenotypes represent a single panmictic population rather than cryptic species.
Macrostemum zebratum
Zebra Caddisfly
Macrostemum zebratum, commonly known as the zebra caddisfly, is a species of netspinning caddisfly in the family Hydropsychidae. It is a medium to large caddisfly recognized by its distinctive patterned wings. As a member of the Hydropsychidae, it constructs silk capture nets in flowing water to filter food particles.
Pachycheles rudis
thickclaw porcelain crab, big-clawed porcelain crab
Pachycheles rudis is a porcelain crab in the family Porcellanidae, commonly known as the thickclaw porcelain crab or big-clawed porcelain crab. It inhabits the East Pacific coast from Baja California to Kodiak, Alaska. The species is a filter feeder that typically occurs in heterosexual pairs and exhibits size-assortative pairing with apparent long-term mate recognition. It is frequently found in crevices, nooks, and interstices, often occupying discarded barnacle shells lined with the bryozoan Alcyonidium.
Parapsyche apicalis
Parapsyche apicalis is a species of net-spinning caddisfly in the family Hydropsychidae, originally described as Arctopsyche apicalis by Banks in 1908. The species belongs to the subfamily Arctopsychinae and is found in North America. As a member of Hydropsychidae, larvae construct fixed retreats and capture nets to filter food particles from flowing water.
Petrolisthes
porcelain crabs
Petrolisthes is a genus of marine porcelain crabs in the family Porcellanidae, containing approximately 50 extant species distributed across temperate and tropical coastal regions of the Pacific Rim and warm Western Atlantic. These small, flattened crabs occupy intertidal and subtidal zones, often forming dense aggregations under rocks and within crevices. Multiple species have been subject to intensive behavioral and ecological study, revealing complex patterns of intraspecific competition, thermal adaptation, and settlement behavior. Two species (P. cinctipes and P. manimaculis) have been sequenced, providing genomic resources for studying physiological responses to climate change.
Petrolisthes armatus
Green Porcelain Crab
Petrolisthes armatus, commonly known as the green porcelain crab, is a small porcellanid crab native to the southwestern Atlantic, particularly Brazil. The species has established invasive populations along the southeastern United States coast, where densities can exceed 30,000 individuals per square meter. Genetic studies confirm it as a single monophyletic species with exceptional geographic range spanning the Atlantic and eastern Pacific. It is frequently parasitized by the bopyrid isopod Aporobopyrus curtatus, which causes parasitic castration.
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flattop crab
Petrolisthes eriomerus, commonly called the flattop crab, is a small porcelain crab inhabiting the eastern Pacific coast of North America. It reaches 20 mm in carapace width and exhibits a distinctly flattened, rounded body form adapted for life under rocks and in crevices. The species employs filter feeding and deposit sweeping to consume diatoms and organic material. It displays notable social behavior, including aggregations and ritualized agonistic interactions between individuals.
Potamyia flava
Yellow Net-spinning Caddisfly
Potamyia flava is a species of net-spinning caddisfly in the family Hydropsychidae, distributed across North America. As a member of the Hydropsychidae, larvae construct fixed capture nets to filter food particles from flowing water. Adults are recognized by their yellow coloration, which distinguishes them from related species. The species has been well-documented through citizen science observations, with over 2,000 records on iNaturalist.
Prosimulium mixtum
Mixed-up Black Fly
Prosimulium mixtum is a species of black fly in the family Simuliidae, commonly known as the mixed-up black fly. It is native to North America and has been studied in the context of spring snowmelt environments and physiological responses to environmental stressors. The species is part of the Prosimulium fuscum/mixtum complex, which has historically caused taxonomic confusion. Adults are small blood-feeding flies, with females requiring blood meals for egg development.
Simuliidae
black flies, buffalo gnats, turkey gnats, white socks
Black flies are small, humpbacked flies in the family Simuliidae, comprising over 2,200 formally described species. Only females bite, using serrated mandibles to slash skin and lap pooled blood for egg development. They are vectors of Leucocytozoon parasites causing leucocytozoonosis in birds and, in some regions, filarial worms causing river blindness in humans. Larvae develop exclusively in flowing freshwater, attaching to submerged substrates with specialized hooks.
Spinicaudata
clam shrimp
Spinicaudata is an infraorder of small, bivalved branchiopod crustaceans commonly known as clam shrimp. They inhabit temporary freshwater pools, saline lakes, and rock holes (gnammas) across arid and semi-arid regions worldwide. The group is characterized by a laterally compressed body enclosed within a hinged, clam-like carapace. Many species produce drought-resistant resting eggs that persist in dry sediments until favorable conditions return. Reproductive modes vary, with some lineages exhibiting androdioecy (hermaphrodites with occasional males) and others gonochorism (separate sexes with ~1:1 ratios).
Wormaldia
Wormaldia is a diverse genus of fingernet caddisflies (family Philopotamidae), comprising approximately 175 extant species globally. It is the second-largest genus in Philopotamidae after Chimarra. Species occur across all biogeographic regions except Australasia, with notable diversification in the Neotropics and Nearctic. The genus includes fossil species from Late Cretaceous Burmese amber, indicating an ancient evolutionary history. Taxonomic revisions have focused heavily on male genitalia morphology for species identification.