Fish and mussels: Importance of fish for freshwater mussel conservation          下载免费PDF全文

Vanessa Modesto  Martina Ilarri  Allan T Souza  Manuel Lopes‐Lima  Karel Douda  Miguel Clavero  Ronaldo Sousa 《Fish and Fisheries》2018,19(2):244-259

Co‐extinctions are increasingly recognized as one of the major processes leading to the global biodiversity crisis, but there is still limited scientific evidence on the magnitude of potential impacts and causal mechanisms responsible for the decline of affiliate (dependent) species. Freshwater mussels (Bivalvia, Unionida), one of the most threatened faunal groups on Earth, need to pass through a parasitic larval (glochidia) phase using fishes as hosts to complete their life cycle. Here, we provide a synthesis of published evidence on the fish–mussel relationship to explore possible patterns in co‐extinction risk and discuss the main threats affecting this interaction. We retrieved 205 publications until December 2015, most of which were performed in North America, completed under laboratory conditions and were aimed at characterizing the life cycle and/or determining the suitable fish hosts for freshwater mussels. Mussel species were reported to infest between one and 53 fish species, with some fish families (e.g., Cyprinidae and Percidae) being used more often as hosts than others. No relationship was found between the breadth of host use and the extinction risk of freshwater mussels. Very few studies focused on threats affecting the fish–mussel relationship, a knowledge gap that may impair the application of future conservation measures. Here, we identify a variety of threats that may negatively affect fish species, document and discuss the concomitant impacts on freshwater mussels, and suggest directions for future studies.  相似文献   

The Effects of Stressful Broodstock Handling on Hormonal Profiles and Reproductive Performance of Rhamdia quelen (Quoy & Gaimard) Females     

Auren Benk Soso  Leonardo José Gil Barcellos  Maria José Ranzani‐Paiva  Luiz Carlos Kreutz  Rosmari Mezzalira Quevedo  Marina Lima  Leonardo Bolognesida Silva  Filipe Ritter  Alexandra Calliari Bedin  Jovani Antônio Finco 《Journal of the World Aquaculture Society》2008,39(6):835-841

Abstract.— A stressful environment induces cortisol that might affect fish breeding and reproduction. In the present work, which aimed to mimic aquacultural conditions of the jundia (Rhamdia quelen) hatcheries in southern South America, females were submitted to normal or stressful handling and the effects of cortisol on serum levels of 17β‐estradiol (E2) and testosterone (T) were determined. In addition, the effect of stress on reproductive parameters such as eggs and swim‐up fry production was also measured. Eight females from a group submitted to stressful handling (SH) conditions and eight females from a group with normal handling (NH) conditions were captured for blood sampling at D 0 and at D 1, 10, 20, 30, and 40 of the experiment. A typical cortisol response was observed in the SH females group in that they presented higher cortisol level in contrast to the NH female group, in all days sampled, except at D 0. In the 10th and 20th d, the E2 levels were lower in SH females, but cortisol levels were higher, suggesting an effect of cortisol on E2 production and/or release. Stressful handling appeared to affect both the number and the quality of the gametes because a lower number of oocytes was stripped from SH females, and from SH fertilized eggs, a lower number of viable swim‐up fry was obtained to be transferred to earthen larviculture ponds. Taken together, the results indicated that stressful handling of broodstock impairs R. quelen reproduction.  相似文献   

Aspects of forest restoration and hydrology:the hydrological function of litterOA     

Luara Castilho Pereira  Leonardo Balbinot  Marcelle Teodoro Lima  Julieta Bramorski  Kelly Cristina Tonello 《林业研究》2022,(2):543-552

Although forests play important roles in the hydrological cycle,there is little information that relates the water retention capacity of litter in areas under passive restoration,especially in Cerrado savannas.This study relates litter levels to water holding capacity and effective water retention among forest fragments under different passive restoration stages:46,11,and 8 years to better understand litter hydrological functions in the Cerrado.Water retention c apacity and effective water reten...  相似文献   

Characterization of Pterocarpus macrocarpus (pradoo wood) biochar and its effect on the retention properties of sandy soils in Northeast Thailand     

Siwaporn Siltecho  Nopmanee Suvannang  Juthamard Kaiphoem  Erika Medeiros  José Romualdo de Sousa Lima  Nattaporn Prakongkep  Robert Gilkes  Claude Hammecker 《Soil Use and Management》2022,38(2):1293-1306

Pradoo wood biochar has been tested in order to explore sustainable solutions to the development of agriculture on poor sandy soils in marginal areas in Northeast Thailand. Some basic physicochemical properties of biochar, for example pore size distribution, cation exchange capacity (CEC), specific surface area (SSA), and water and nutrient adsorption, were determined and compared to soil properties in order to determine appropriate biochar application to soil. Pradoo wood biochar showed important adsorption properties with high SSA, CEC and nutrient adsorption. The water retention properties were also improved on the dry end of the water retention curve. Phosphorous and ammonium adsorption–desorption isotherms were established and their respective affinity for the biochar surface was quantified, by the means of a retention index and thermodynamical parameters. We found that despite excellent retention properties, biochar needs to be added in large amounts (between 10 and 70 kg m⁻²) to soil to be able to modify noticeably the resulting soil properties.  相似文献   

Do water dynamics and land use in riparian areas change the spatial pattern of physical–mechanical properties of a Cambisol?     

da Silva  Reginaldo Barboza  Iori  Piero  Tavares  Rose Luiza Moraes  de Souza  Zigomar Menezes  de Lima  Camila Cassante  de Melo Silva  Francisca Alcivânia  de Souza Bento  Marília 《Precision Agriculture》2022,23(3):984-1007

Precision Agriculture - Changes in land use in riverside ecosystems added to the flood and ebb regimes of rivers modify the spatial variability of the physical–mechanical attributes of soil,...  相似文献