Copepod nauplii are either ambush feeders that feed on motile prey or they produce a feeding current that entrains prey cells. It is unclear how ambush and feeding-current feeding nauplii perceive and capture prey. Attack jumps in ambush feeding nauplii should not be feasible at low Reynolds numbers due to the thick viscous boundary layer surrounding the attacking nauplius. We use high-speed vi...

Zooplanktons are microscopic organisms, which are integral components of aquatic food web, as they contribute significantly to productivity of freshwater ecosystems. They are also very sensitive to environmental changes; therefore they make ideal indicator organisms. Total zooplankton (Rotifer, Cladocera, Copepod and Ostracod) abundance was significantly more in Cauvery river with the mean abun...

The escape response to fluid mechanical signals was examined in 6 protists, 4 ciliates and 2 dinoflagellates. When exposed to a siphon flow, 3 species of ciliates, Balanion comatum, Strobilidium sp., and Mesodinium pulex, responded with escape jumps. The threshold deformation rates required to elicit an escape ranged between 1.8 and 3 s–1. Escape speeds varied between 100 to 150 body length s–1...

Glyphosate-based herbicides (e.g. Roundup) are extensively used in the aquatic environment, but there is a paucity of data on the toxicity of the formulated products and the influences by environmental factors. In this study, the acute toxicity of technical-grade glyphosate acid, isopropylamine (IPA) salt of glyphosate, Roundup and its surfactant polyoxyethylene amine (POEA) to Microtox bacteri...

Alveolate (ciliates and dinoflagellates) grazers are integral components of the marine food web and must therefore be able to sense a range of mechanical and chemical signals produced by prey and predators, integrating them via signal transduction mechanisms to respond with effective prey capture and predator evasion behaviors. However, the sensory biology of alveolate grazers is poorly underst...

Recent field studies indicate that dinoflagellates are key degraders of copepod fecal pellets. This study is the first to publish direct evidence of pellet grazing by dinoflagellates. Feeding and growth on copepod fecal pellets were studied for both heterotrophic (4 species) and mixotrophic dinoflagellates (3 species) using a combination of classic incubation experiments and video recordings of...

Stressors resulting from, or exacerbated by, human activities increasingly alter ecological systems. Behavioral responses that enhance survival of stressed individuals may be critical for local populations to persist. Although the types and intensities of stressors can vary over the geographic range of a species, little is known regarding geographical variation in adaptive behavioral responses ...