Daphnia

Daphnia are small planktonic freshwater crustaceans, commonly called water fleas. They filter suspended food and reproduce through both clonal and sexual cycles.

Cladocera: Cladocera are an order of small branchiopod crustaceans, many of which swim with large second antennae. Daphnia belong to this group of water fleas and share its distinctive swimming anatomy.
Cyclic parthenogenesis: Cyclic parthenogenesis alternates between asexual reproduction and sexual reproduction across generations. Daphnia use this cycle to multiply rapidly when conditions are favorable and produce resting eggs when they deteriorate.
Daphnia magna: Daphnia magna is a relatively large water flea species widely used in laboratory research and toxicity testing. Its size and ease of culture make it a standard species for testing chemical effects on Daphnia.
Daphnia longispina: Daphnia longispina is a water flea species found in lakes and other freshwater habitats. It is one of several Daphnia species that form plankton communities in lakes.
Carapace: A carapace is a shell-like covering that protects the bodies of many crustaceans and other animals. Daphnia's transparent carapace encloses most of its body while leaving the head exposed.
Photoperiodism: Photoperiodism is a biological response to the duration of light and darkness in a daily or seasonal cycle. Day length can help cue Daphnia to switch toward sexual reproduction and resting-egg production.
Daphnia pulex: Daphnia pulex is a widespread freshwater water flea and a model organism in ecological and genomic research. Its populations and genome have supported studies of adaptation and ecological variation within Daphnia.
Daphnia ambigua: Daphnia ambigua is a small water flea species found in freshwater habitats, including lakes and ponds. Its populations have been studied for responses to fish predation and changing environments.
Phyllopodous limb: A phyllopodous limb is a flattened, leaf-like appendage used in swimming, feeding, or respiration. Daphnia's thoracic limbs beat rhythmically to move water and capture food.
Predator-induced defenses: Predator-induced defenses are changes in an organism's traits triggered by cues associated with predators. Chemical signals from predators can alter Daphnia's shape, behavior, or life history.

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