Daily timescale dynamics of planktonic foraminifera shell-size distributions

Planktonic foraminifera (PF) shells comprise a significant fraction of the global oceanic carbonate flux and serve as primary archive history oceans. Yet, limited understanding their life cycles dynamics biological rhythms, hampers application palaeoceanographic proxies. Here, we present ten PF species shell-size distributions at daily timescale resolution in Gulf Aqaba (GOA), northern Red Sea. We report diameter measurements ~13,500 shells, associated with species, retrieved using an automated time-series sediment trap deployed water depth ~410 m (seafloor 610 m) throughout more than full annual cycle between 2015 2016. Most display wide intraspecific distribution among adult PF, while six abundant ( G. ruber , rubescens + tenellus glutinata calida siphonifera ) significantly smaller shell-sizes compared corresponding specimens from traps seafloor sediments across other tropical, subtropical upwelling regions. The results indicate that generation can be classified according to three patterns: (1) Quiescent : minimal extended due unfavorable conditions food scarcity when column is stratified oligotrophic, (2) Transient gradual increase Chlorophyll- (Chl- concentrations availability enhance shorter life-cycles, although do not necessarily reach maximal shell-sizes, (3) Successive fluxes Chl- are maximal, time individuals might growth shell-sizes.