Among the thousands of unicellular phytoplankton species described in the sea, some frequently occurring and bloom-forming marine dinoflagellates are known to produce the potent neurotoxins causing paralytic shellfish poisoning. The natural function of these toxins is not clear, although they have been hypothesized to act as a chemical defence towards grazers. Here, we show that waterborne cues...

The heterotrophic dinoflagellate Protopemdinium cf. divergens, known as prey for adult copepods, itself feeds on copepod eggs and early naupliar stages. One to several P. cf. divergens can attack an egg or nauplius larger than themselves. The time for an egg to be digested was proportional to the number of P. cf. divergens attacking it. Ingestion rates of P, cf. djvergens on Acartia tonsa eggs ...

Fluorogenic assays for a set of five hydrolytic enzymes involved in digestion and food utilization (alanine and arginine aminopeptidase, lipase/esterase, chitobiase, and beta-glucosidase) were optimized to measure activities of these enzymes in the same extracts of individual small North Sea copepods. The enzyme activities of Acartia clausi, Centropages typicus, Corycaeus anglicus, Paracalanus ...

DMSP-consuming bacteria (DCB) were recovered from the body and fecal pellets of the copepod Acartia tonsa (Dana). The most probable number of DCB associated with starved A. tonsa was 9.2x10(2) cells copepod(-1). The abundance of DCB recovered from the copepod body increased to 1.6-2.8x10(4) after the copepod fed on DMSP-containing alga. DCB abundance associated with fecal pellets averaged 1.2x1...

Samples historically collected and analysed by the Continuous Plankton Recorder survey were used to examine long-term (1958 to 1994) patterns in the normal diel vertical migrat~on (NDVM) behaviour of 7 copepod taxa in the North Sea: Calanus finmarchicus C5-C6; Calanus spp. Cl-C4; Cenlropages typicus; Centropages hamatus; Temora longicornis; Acartia clausii and Para-Pseudocalanus (this last grou...

Acartiella faoensis, previously known as Acartia (Acartiella) is a calanoid copepod which was observed during biodiversity survey, July-August of 2018, on the lower-middle stretch Hooghly River (upper reaches estuary). The species reported for first time from aforementioned locality well anywhere eastern India and perhaps entire country. Individuals belonging to both sexes have been collected s...

In earlier single-species toxicity tests we showed the negative effects on the calanoid copepod Acartia tonsa upon exposure to cypermethrin, a pesticide used in treatment for sea lice in salmon farming. In the present study we assessed effects at a higher level of biological organization and under a more realistic exposure scenario using mesocosms. The results showed that simulated field studie...

Metazooplankton abundance, biomass (<80 μm, 200-500 μm and >500 μm) and community structure in the Ahe atoll were studied together with their relationships with environmental factors (temperature, salinity, wind) and trophic factors (phytoplankton, bacteria, heterotrophic nanoflagellates (HNF) and ciliates) during three periods in 2008-2009. Meroplankton, mainly bivalve and gastropod larvae, wa...