We describe the first genetic linkage map for Daphnia pulex using 185 microsatellite markers, including 115 new markers reported in this study. Our approach was to study the segregation of polymorphisms in 129 F2 progeny of one F1 hybrid obtained by crossing two genetically divergent lineages of Daphnia isolated from two Oregon populations. The map spanned 1206 Kosambi cM and had an average int...

Phenotypic plasticity is the ability held in many organisms to produce different phenotypes with a given genome in response to environmental stimuli, such as temperature, nutrition and various biological interactions. It seems likely that environmental signals induce a variety of mechanistic responses that influence ontogenetic processes. Inducible defenses, in which prey animals alter their mo...

Diffusible gasses and small molecule transmitters are classes of compounds used by neurons and other cell types for local and hormonal signaling. In crustaceans, there is evidence for the neuronal production of the gasses nitric oxide (NO) and carbon monoxide (CO), as well as the small molecule transmitters acetylcholine, glutamate and GABA. While much is known about the physiological roles pla...

It is well known that most daphnid species have several attractive life history characteris‐ tics such as cyclical parthenogenesis, environmental sex determination, and predator-in‐ duced defense formation. Recent advances in high-throughput omics technologies make it easy to obtain a huge number of potential candidate factors involved in environmental stimuli-triggered phenotypic alterations. ...

Acute toxicity experiments with purified toxins show that four species of zooplankton differ markedly in their physiological sensitivity to cyclic peptide hepatotoxins from Microcystis ueruginosu (microcystin-LR1 and Noduluria spumigenu (nodularin). The copepod Diaptomus birgei was most sensitive (48-h LC,, for microcystin-LR ranged from 0.45 to 1.00 pg ml-l), Daphnia pulicuriu was least sensit...