Ageing and Caloric Restriction in a Marine Planktonic Copepod

Abstract

Planktonic copepods are a key group in the marine pelagic ecosystem, linking primary production with upper trophic levels. Their abundance and population dynamics are constrained by the life history tradeoffs associated with resource availability, reproduction and predation pressure. The tradeoffs associated with the ageing process and its underlying biological mechanisms are, however, poorly known. Our study shows that ageing in copepods involves a deterioration of their vital rates and a rise in mortality associated with an increase in oxidative damage (lipid peroxidation); the activity of the cell-repair enzymatic machinery also increases with age. This increase in oxidative damage is associated with an increase in the relative content of the fatty acid 22:6(n-3), an essential component of cell membranes that increases their susceptibility to peroxidation. Moreover, we show that caloric (food) restriction in marine copepods reduces their age-specific mortality rates, and extends the lifespan of females and their reproductive period. Given the overall low production of the oceans, this can be a strategy, at least in certain copepod species, to enhance their chances to reproduce in a nutritionally dilute, temporally and spatially patchy environment.

Carbonyl scavengers as pharmacotherapies in degenerative disease: Hydralazine repurposing and challenges in clinical translation

“…While LDEs are known contributors to spontaneous proteome damage during organismal ageing, any investigation of the potential for carbonyl scavengers to afford health benefits by suppressing such damage are complicated by the complexities and cost of performing lifespan extension studies in mammalian species. In recent times, the emergence of experimental approaches involving "simple" model organisms with short lifespans have allowed novel investigations of the effects of carbonyl-scavengers on the functional deficits that accompany ageing [79,80].…”

Motile behavior and predation risk in planktonic copepods

“…Zooplankton ecology is most frequently studied from the perspective of feeding, growth, and reproduction (Alcaraz and Saiz ). Mortality, however, has received comparatively less attention despite its importance to population dynamics (Verity and Smetacek ; Hirst and Kiørboe ; Saiz et al ). Predation is considered one of the major sources of mortality in zooplankton (Hirst and Kiørboe ).…”

Sex-Dependent Effects of Caloric Restriction on the Ageing of an Ambush Feeding Copepod

“…Later, Saiz et al . 13 , studying the closely related copepod species Paracartia grani , found that the deterioration of vital rates and rise in mortality associated with age (true senescence) were related to an increase in oxidative damage (lipid peroxidation). This increase in oxidative damage was accompanied by a rise in the relative content of the fatty acid 22:6(n-3), an essential component of cell membranes that increases their susceptibility to peroxidation.…”

“…Saiz et al . 13 reported the first evidence of the effects of caloric restriction in marine copepods. As in many other animal models, caloric (food) restriction lowered age-specific mortality rates and increased survival times of the calanoid copepod P. grani .…”

“…It is still uncertain, however, whether the findings of Saiz et al . 13 can be generalized to planktonic copepods with markedly different life history traits, and for which reproductive and somatic costs may have a different balance.…”