The influence of dissolved organic matter (DOM) on sodium regulation and nitrogenous waste excretion in the zebrafish (Danio rerio).

摘要: ABSTRACT Dissolved organic matter (DOM) is both ubiquitous and diverse in composition natural waters, but its effects on the branchial physiology of aquatic organisms have received little attention relative to other variables (e.g. pH, hardness, salinity, alkalinity). Here, we investigated four chemically distinct DOM isolates (three natural, one commercial, ranging from autochthonous highly allochthonous, all at ∼6 mg C l −1 ) gill ionoregulation nitrogenous waste excretion zebrafish acclimated either circumneutral (7.0–8.0) or acidic pH (5.0). Overall, lower tended increase net ammonia excretion, K + loss [ 3 H]PEG-4000 clearance rates (indicators transcellular paracellular permeability, respectively). However, unidirectional Na efflux, urea drinking were unaffected. sources stimulate influx rate exerted subtle concentration-dependent kinetics uptake, increasing maximum transport capacity. All reduced passive efflux regardless negligible rate, clearance, so mechanism reduction remains unclear. these actions appear beneficial ionoregulatory homeostasis zebrafish, some may be related physico-chemical properties sources. They are very different those seen a recent parallel study Daphnia magna using same isolates, indicating that species specific.