Irrigation by benthic macrofauna has a major influence on the biogeochemistry and microbial community structure of sediments. Existing quantitative models of bioirrigation rely primarily on chemical, rather than ecological, information and the depth-dependence of bioirrigation intensity is either imposed or constrained through a data fitting procedure. In this study, stochastic simulations of 3...

letter to the editor

The Southern sea otter (Enhydra lutris nereis) is listed as threatened under the Endangered Species Act. The population began a pattern of slow decline in 1995. The decline was attributed to high adult mortality rates with infectious disease being the major cause of death. Multiple pathogens were implicated in these deaths including opportunistic pathogens such as Coccidiodes immitis and Toxopl...

The sarcoplasmic calcium-binding protein (SCP) of the sandworm Nereis possesses three Ca2(+)-Mg2+ sites but no Ca2(+)-specific site. Binding of Mg2+, but not of Ca2+, displays a marked positive cooperativity. The apparent cooperativity of Ca2+ binding in the presence of Mg2+ results from the allostery in Mg2+ dissociation. Binding of the first Ca2+ or Mg2+ induces all the conformational change,...

H U B L (1956) demonstrated that if the supra-oesophageal ganglion of lumbricid oligochaetes is removed at the time of amputation of a number of posterior segments, caudal regeneration is totally inhibited, but if the ganglion is not removed until 24-48 hours after amputation of the posterior segments, regeneration proceeds at the normal rate. A comparable phenomenon may occur in nereid polycha...

Nereis limnicola was described by Johnson (1903) from the fresh-water Lake Merced in San Francisco, California. Since that time no reports of its occurrence have been published. Hartman (1938) noted that the boundaries and bed of the lake have been "a ltered by dredging and roadbuilding operations , and that what was once the type locality of Nereis limnicola now lies many feet below a road bed...

The marine environment is becoming increasingly contaminated by environmental pollutants with the potential to damage DNA, with marine sediments acting as a sink for many of these contaminants. Understanding genotoxic responses in sediment-dwelling marine organisms, such as polychaetes, is therefore of increasing importance. This study is an exploration of species-specific and cell-specific dif...