Animals are exposed, in the natural environment, to a range of human activity related dissolved chemicals that are potentially impacting on their fitness. The animals responses to such stress determines its fitness, physiology and in case of chemical signals also its behaviour. If physical or chemical changes in the ecosystem make the detection of such a chemical impossible, then it can be reas...

ONE of the classic descriptions of the insemination process is that of F. R. Lillie (1911) in the egg of the annelid, Nereis. According to Lillie, there exists beneath the vitelline membrane of the unfertilized Nereis egg a wide cortical layer. He describes it as "a coarsely alveolar layer with homogeneous alveolar contents. The walls of the alveoli are continuous internally with the protoplasm...

In this study, the toxicities of sediment-associated silver added to sediment as commercially available silver nanoparticles (Ag NPs, 20 and 80 nm) and aqueous Ag (AgNO3) to the estuarine polychaete, Nereis (Hediste) diversicolor, were investigated for both individual and subcellular endpoints after 10 d of exposure. Both Ag NP types were characterized in parallel to the toxicity studies and fo...

Patterns of change in the structure of bacterial communities monitored by ribosomal intergenic spacer analysis (RISA) in oil contaminated sediments inhabited or not by the marine polychaete Nereis diversicolor were studied during 45 days under laboratory conditions. Results supported by principal component analysis showed a marked response of the bacterial communities to the oil contamination a...

1. The physiological effect upon the eggs of Nereis of homogeneous groups of beta-rays of different velocities is proportional to their ability to ionize air. 2. beta-rays of low velocity produce a greater amount of physiological change than the same number of rays of high velocity. 3. These conclusions are consistent with, but do not prove, the view that the physiological effects of radiations...

(With One Plate and Eight Text-figures) THE locomotory movements of a typical polychaete worm, such as Nereis diversicolor, are of interest in that they are effected by two distinct mechanisms, (i) a series of parapodia which act as levers comparable to the appendages of terrestrial animals, (ii) the longitudinal muscles of the body. When Nereis is moving slowly over a solid surface, only the p...