Predator-induced changes of male and female mating preferences: innate and learned components

While many mati ng pref ere nces have a genetic basis, the question remai ns as to whether and how learning/experience can modify individual mate choice decisions. We used wild-caught (predator-experienced) and Fi laboratory-reared (predator-naive) invasive Western mosquitofish Gambusia affinis from China to test whether mating preferences (assessed in a first mate choice test) would change under immediate predation threat. The same individuals were tested in a second mate choice test during which 1 of 3 types of animated predators was presented: 1) a co-occurring predator, 2) a co-evolved but not currently co-occurring predator, and 3) a non-piscivorous species as control. We compared preference scores derived from both mate choice tests to separate innate from experiential effects of predation. We also asked whether predator-induced changes in mating preferences would differ betwee n sexes or depend on the choosing individual's personality type and/or body size. Wild-caught fish altered their mate choice decisions most when exposed to the co-occurring predator whereas laboratory-reared individuals responded most to the co-evolved predator, suggesting that both innate mechanisms and learning effects are involved. This behavior likely reduces individuals' risk of falling victim to predation by temporarily moving away from high-quality (i.e., conspicuous) mating partners. Accordingly, effects were stronger in bolder than shyer, large- compared with small-bodied, and female compared with male focal individuals, likely because those phenotypes face an increased predation risk overall. Our study adds to the growing body of literature appreciating the complexity of the mate choice process, where an array of intrinsic and extrinsic factors interacts during decision-making.

Insights into thallium adsorption onto the soil,bamboo-derived biochar,and biochar amended soil in Pomelo orchard

Little information is available on thallium(Tl)adsorption onto biochar amended soil for a relatively long term.In this study,bamboo-derived biochar(BDB),soil in pomelo orchard(SP),and biochar amended soil in pomelo orchard(BSP)were thus used to evaluate the potential remediation of thallium(Tl)using batch-adsorption techniques.Furthermore,we characterized the above-mentioned sorbents’properties related to Tl adsorption to understand Tl’s adsorption mechanisms.The results showed that BDB,SP,and BSP achieved equilibrium adsorption capacity of 96.9,95.43,and 96.76%,respectively,within the initial 15 min.This means that compared to other sorbents,BSP exhibited an efficient sorbent for Tl remediation even when applied in the agricultural field for one year.Multi-layer adsorption played a dominant role in the adsorption of Tl,which was supported by the suitability of Freundlich model for describing the adsorption behavior of Tl onto the selected sorbents.In addition,the pseudo-second kinetic order models strongly fitted Tl’s adsorption onto BDB,SP,and BSP,indicating that the process was accompanied by chemical adsorption.Observed on the surface of BDB by a Fourier Transform Infrared Spectrometer(FTIR)and an X-ray photoelectron spectroscopy(XPS),the presence of O-H groups and PO_(4)^(3−)might promote chemical adsorption of Tl onto BDB.Overall,these findings can provide insights into comprehensively developed bamboo-derived biochar technology to remediate Tl contamination in agricultural soils.