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Pulsed-resource dynamics increase the asymmetry of antagonistic coevolution between a predatory protist and a prey bacterium
2011
Temporal resource fluctuations could affect the strength of antagonistic coevolution through population dynamics and costs of adaptation. We studied this by coevolving the prey bacterium Serratia marcescens with the predatory protozoa Tetrahymena thermophila in constant and pulsed-resource environments for approximately 1300 prey generations. Consistent with arms race theory, the prey evolved to be more defended, whereas the predator evolved to be more efficient in consuming the bacteria. Coevolutionary adaptations were costly in terms of reduced prey growth in resource-limited conditions and less efficient predator growth on nonliving resource medium. However, no differences in mean coevol…
Punishment of polygyny
1999
We investigated the evolution of monogamy (one male, one female) and polygyny (one male, more than one female). In particular, we studied whether it is possible for a mutant polygynous mating strategy to invade a resident population of monogamous breeders and, alternatively, whether a mutant monogamy can invade resident polygyny. Our population obeys discrete-time Ricker dynamics. The role of males and females in the breeding system is incorporated via the harmonic birth function. The results of the invasability analysis are straightforward. Polygyny is an evolutionarily stable strategy mating system; this holds throughout the examined range of numbers of offspring produced per female. So t…
Is Mating Alone Enough to Inhibit Infanticide in Male Bank Voles?
2010
Infanticide, the killing of conspecific young, is commonly recognized as an adaptive behavioural strategy enhancing the fitness of the perpetrator. Infanticide is supposed to be inhibited in several male rodent species after mating with a time lag to the time when perpetrators own offspring would be born. This is because males with no parental care do not recognize their own offspring. It has been suggested that copulation alone is enough to inhibit infanticidal behaviour in male rodents. Infanticidal behaviour occurs in more than 50% of male bank voles (Myodes glareolus), and offspring loss because of infanticide may have a great effect on breeding success and population recruitment. In a …
Effect of Agronomic Practices on Yield and Quality of Borage at Harvest and During Storage as Minimally-Processed Produce
2020
Borage (Borago officinalis L.) is a hairy pubescent herb known throughout the world for its folk medicinal uses, as well as for many culinary uses. There is still little information on the cultivation needs of this species, especially for its use as vegetable crop and as fresh-cut produce. Hence, the aim of the research was to study the effects of agronomic practices on yield and quality of borage and on the storability as minimally-processed product. Two experiments were carried out in two consecutive years in order to evaluate the effect of plant density and plastic mulching on yield and quality of two borage accessions at harvest and during storage as minimally-processed produce for 14 d…
Costs and Benefits of Experimentally Induced Changes in the Allocation of Growth versus Immune Function under Differential Exposure to Ectoparasites
2010
Background Ecological immunology has focused on the costs of investment in immunocompetence. However, understanding optimal resource allocation to immune defence requires also identification of its benefits, which are likely to occur only when parasites are abundant. Methodology We manipulated the abundance of parasitic hen fleas in blue tit (Cyanistes caeruleus) nests, and supplemented their hosts, the nestlings, with methionine (a sulphur amino acid enhancing cell-mediated immunity) during day 3–6. We found a significant interaction between these two experimental factors on the development of immune defences and growth rates. Only in parasitized nests did methionine supplementation boost …
Could male tergal secretions be considered as a nuptial gift in the Madeira cockroach?
2008
International audience; Many male insects provide somatic nuptial gifts that may strongly influence reproductive fitness, ensuring effective copulation or mediating paternal resource benefits in offspring. Although the courtship feeding behaviour on tergal gland secretions has been described in numerous cockroaches, studies on the function of these so-called nuptial gifts are lacking in this group. In this study, we examined, in the Madeira cockroach, Leucophaea maderae, the functional significance of tergal secretions by manipulating their availability on the back of males. We tested whether male tergal secretions function as a form of mating effort, and/or as a form of paternal investment…
Phenotypic plasticity in growth and fecundity induced by strong population fluctuations affects reproductive traits of female fish
2016
Fish are known for their high phenotypic plasticity in life-history traits in relation to environmental variability, and this is particularly pronounced among salmonids in the Northern Hemisphere. Resource limitation leads to trade-offs in phenotypic plasticity between life-history traits related to the reproduction, growth, and survival of individual fish, which have consequences for the age and size distributions of populations, as well as their dynamics and productivity. We studied the effect of plasticity in growth and fecundity of vendace females on their reproductive traits using a series of long-term incubation experiments. The wild parental fish originated from four separate populat…
Personality affects zebra finch feeding success in a producer-scrounger game.
2011
7 pages; International audience; Recent evidence strongly suggests that natural selection can favour the evolution of consistent individual differences in behaviour ('personalities'). Indeed, personality shows heritable variation and has been linked to fitness in many species. However, the fitness effects of personality are highly variable within and between species. Furthermore, the nature of the causal influence of personality on an organism's fitness remains unclear so far. Competition has been proposed as a factor modulating this relationship. Thus, personality has been found to affect individual success in competition by interference in a few species, but its influence in scramble comp…
Long-term fitness consequences of high yolk androgen levels: sons pay the costs
2012
Summary 1. Early growth conditions, for example hormonal environment during embryonic development, may have long-lasting effects on behaviour and phenotype, with subsequent fitness consequences. Yolk androgens have been shown to affect various offspring traits in the short-term, but fitness consequences for either offspring or parents, a prerequisite for studying the adaptiveness of this maternal effect, are poorly known in the wild. 2. We experimentally elevated yolk androgen levels of whole clutches in a wild population of collared flycatchers (Ficedula albicollis) and investigated the long-term effects of yolk androgens on offspring local recruitment, parental return rate, and timing and…
Effect of peracetic acid on levels of geosmin, 2-methylisoborneol, and their potential producers in a recirculating aquaculture system for rearing ra…
2019
Abstract In recirculating aquaculture systems (RAS)s, off-flavors and odors, mainly caused by geosmin (GSM) and 2-methylisoborneol (MIB), can accumulate in the flesh of fish from RAS water, reducing the profitability of production. In this study, peracetic acid (PAA) was applied in three application intervals to pump sumps of rainbow trout (Oncorhynchus mykiss) reared in RAS. Using a real-time polymerase chain reaction (qPCR), the potential off-flavor producers were quantified using geoA and MIB synthase genes. Streptomyces was identified as the major GSM producer, and biofilters showed the highest number of potential off-flavor producers. Concentrations of GSM and MIB were analyzed in the …