The impact of selected abiotic factors on zooplankton hatching process through real-time, in-situ observation

Current studies on abiotic impacts on marine microorganisms often focus on endpoint analysis (e.g., hatching rates, survival). Here, we demonstrate that a mechanistic understanding can be obtained through real-time measurement of respiration and morphology in controlled microenvironments over extended time periods. As a demonstration, temperature and salinity are chosen to represent critical abiotic parameters that are also threatened by climate change and a target species of Artemia, a prominent zooplankton whose reproduction can affect the marine food pyramid. Different temperatures (20, 35, and 30{o}C) and salinities (0, 25, 50, and 75 ppt) are shown to significantly alter the duration of hatching stages, metabolic rates, and hatchability. Higher temperatures and moderate salinity boosted metabolic reactivation of latent cysts, while higher temperatures alone sped up the process. Hatchability is inversely related to the duration of the differentiation stage of hatching, which persisted longer at lower temperatures and salinities. Initial oxygen availability affects respiration but not hatchability owing to temperature and salinity interactions. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/524934v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@1d796aborg.highwire.dtl.DTLVardef@e4cc10org.highwire.dtl.DTLVardef@111415corg.highwire.dtl.DTLVardef@1da1414_HPS_FORMAT_FIGEXP M_FIG C_FIG