Resting-eggs
Guides
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.
Acartia
Acartia is a genus of marine calanoid copepods comprising the majority of species in the family Acartiidae. They are small, planktonic crustaceans found primarily in temperate coastal and estuarine waters worldwide. The genus includes ecologically important species such as A. tonsa, which is among the most abundant and well-studied estuarine copepods globally. Acartia species serve as key intermediaries in aquatic food webs and are increasingly used as model organisms for studying coastal plankton dynamics, thermal ecology, and phylogeographic patterns.
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.
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.
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.
Laevicaudata
clam shrimp
Laevicaudata is a suborder of small branchiopod crustaceans commonly known as clam shrimp, characterized by a laterally compressed bivalved carapace that encloses the entire body. The group contains approximately 36 described species in the single family Lynceidae, with the genus Lynceus as the primary representative. Laevicaudatans inhabit temporary freshwater habitats worldwide, with documented occurrences across six continents including remote insular locations. The group has been historically understudied compared to other large branchiopods, though recent taxonomic revisions have clarified species boundaries, particularly in Australia where six species are now recognized.
Lepidurus
tadpole shrimp
Lepidurus is one of two extant genera of tadpole shrimp (order Notostraca), distinguished from Triops by morphological and ecological traits. Species inhabit temporary freshwater pools, vernal pools, and permanent lakes across diverse climates from Arctic tundra to desert regions. The genus exhibits notable life history flexibility, with resting eggs capable of surviving desiccation and freezing for decades. Some species are of conservation concern due to habitat specificity, while others serve as agricultural pests or bioindicators of environmental change.
Podon
Podon is a genus of marine cladocerans in the family Podonidae, characterized by onychopod morphology. The genus includes at least four described species: P. intermedius, P. leuckarti, P. leuckartii, and P. schmackeri. Members are euryhaline and eurythermal, inhabiting estuarine and coastal marine waters. Populations exhibit strong seasonal dynamics, with spring and fall peaks and summer disappearance in temperate regions.
Polyphemus pediculus
Polyphemus pediculus is a predatory freshwater cladoceran crustacean in the family Polyphemidae. It is distributed throughout the Northern Hemisphere but exhibits significant genetic structuring, representing at least nine largely allopatric cryptic species rather than a truly cosmopolitan population. The species displays complex reproductive behavior involving both parthenogenetic and gamogenetic (sexual) phases, with pronounced seasonal and daily rhythms in swarming activity.