Both attraction and repulsion from linearly polarized light have been observed in zooplankton. A dichotomous choice experiment, consisting of plankton light traps deployed in natural waters at a depth of 30 m that projected either polarized or unpolarized light of the same intensity, was used to test the hypothesis that the North Atlantic copepod, Calanus spp., is linearly polarotactic. In addi...

The distance at which plankters can detect and thus interact with each other depends on their sensitivity, size, and motion, as well as the hydrodynamic characteristics of their behaviour. Through a simple consideration of the distribution of forces exerted on the ambient fluid by different plankton behaviours, it is possible to deduce the spatial scale over which the associated hydromechanical...

Factors that directly impact horizontal transmission of the microsporidium Amblyospora albifasciati to its intermediate copepod host, Mesocyclops annulatus were examined in laboratory bioassays. Results were evaluated in relation to life history strategies that facilitate persistence of the parasite in natural populations of its definitive mosquito host, Ochlerotatus albifasciatus. A moderately...

Using life history theory we make predictions of mortality rates in marine epi-pelagic copepods from field estimates of adult fecundity, development times and adult sex ratios. Predicted mortality increases with temperature in both broadcast and sac spawning copepods, and declines with body weight in broadcast spawners, while mortality in sac spawners is invariant with body size. Although the m...

We investigated physiological traits associated with a reproductive-resting stage in adult female harpacticoid copepods, Coullana canadensis (Willey). Our hypothesis was this stage represents a life-history strategy that could increase ®tness by improving winter survivorship and future reproductive success in spring. To test if physiological rates are suppressed in this stage, we compared gut-c...

Sea lice (copepods) are widespread pathogens in marine teleost cultivation around the world. The sea louse Caligus mutabilis Wilson, 1905, is recorded here for the first time in sea-farmed gag grouper, Mycteroperca microlepis, in Brazil.

Medusae, siphonophores, and ctenophores are planktivorous predators operating at higher trophic levels in marine ecosystems of a wide range of productivity. It has been hypothesized that high-productivity ecosystems such as areas of upwelling tend towards food chains dominated by larger phytoplankton, large copepods, and ultimately many species of fish rather than gelatinous predators; ecosyste...