53 research outputs found
Modes, mechanisms and evidence of bet hedging in rotifer diapause traits
In this contribution, we review our knowledge on bet-hedging strategies associated with rotifer diapause. First, we describe the ecological scenario under which bet hedging is likely to have evolved in three diapause-related traits in monogonont rotifer populations: (1) the timing of sex (because diapausing eggs are produced via sexual reproduction), (2) the sexual reproduction ratio (i.e. the fraction of sexually reproducing females) and (3) the timing of diapausing egg hatching. Then, we describe how to discriminate among bet-hedging modes and discuss which modes and mechanisms better fit the variability observed in these traits in rotifers. Finally, we evaluate the strength of the empirical evidence for bet hedging in the scarce studies available, and we call for the need of research at different levels of biological complexity to fully understand bet hedging in rotifer diapause
Bending the rules: exploitation of allochthonous resources by a top-predator modifies size-abundance scaling in stream food webs
Body massâabundance (MâN) allometries provide a key measure of community structure, and deviations from scaling predictions could reveal how crossâecosystem subsidies alter food webs. For 31 streams across the UK, we tested the hypothesis that linear logâlog MâN scaling is shallower than that predicted by allometric scaling theory when top predators have access to allochthonous prey. These streams all contained a common and widespread top predator (brown trout) that regularly feeds on terrestrial prey and, as hypothesised, deviations from predicted scaling increased with its dominance of the fish assemblage. Our study identifies a key beneficiary of crossâecosystem subsidies at the top of stream food webs and elucidates how these inputs can reshape the sizeâstructure of these âopenâ systems
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