Identification of stocked muskellunge and potential for distinguishing hatchery‐origin and wild fish using pelvic fin ray microchemistry

The effectiveness of pelvic fin ray microchemistry of muskellunge, Esox masquinongy Mitchill, to identify stocked individuals along with the potential to identify naturally reproduced fish were evaluated. Fish and water samples were obtained from one hatchery and seven lakes with natural differences in water Sr:Ca to determine whether location‐specific environmental signatures were recorded in sectioned muskellunge pelvic fin rays, including fish of known environmental history. Water and fin ray Sr:Ca were strongly correlated. Six lakes in Illinois possessed Sr:Ca signatures that were distinct from the hatchery where muskellunge were raised, resulting in pronounced shifts in Sr:Ca across sectioned fin rays of stocked fish. Hatchery and lake‐specific Sr:Ca signatures were stable across years. Sixteen of 19 individual fish known to have been stocked based on PIT tags implanted at stocking were correctly identified as hatchery‐origin fish using fin ray core Sr:Ca. Results also indicated that the hatchery Sr:Ca signal can be retained for at least 7 years in fin rays of stocked fish. Fin ray microchemistry is a non‐lethal approach for determining environmental history of muskellunge that could be used to assess movement patterns in lake and river systems and the degree to which muskellunge populations are supported by natural reproduction and stocking.     

Otolith chemistry does not just reflect environmental conditions: A meta‐analytic evaluation

Fish otoliths are widely used to answer biological and ecological questions related to movements and habitat use based on their chemical composition. Two fundamental assumptions underlie otoliths as environmental tracers and proxies for reconstructing exposure histories: (i) otolith chemistry reflects water chemistry, and (ii) ambient environmental conditions affect otolith element incorporation. Here, we test these assumptions for Sr and Ba through meta‐analyses. Our first meta‐analysis confirmed a correlation between concentrations of Sr:Ca and Ba:Ca in otoliths and the surrounding water, both elements displaying positive otolith–water correlations. The second meta‐analysis examined the relative influences of salinity and temperature on otolith Sr and Ba partition coefficients (an index of otolith element regulation). Our environmental effects meta‐analysis confirmed that otolith Sr and Ba are affected by temperature and salinity; however, study‐level covariates (e.g., water chemical concentrations and species ecological niche) influenced otolith element incorporation, and this varied by element. These findings confirm that even though otolith chemistry and elemental incorporation are differentially affected by environmental conditions, other factors play a decisive role. While we focused on studies that directly linked water and otolith chemistry, systematic reviews are key to further demonstrate the link between otolith chemistry and extrinsic and intrinsic factors. Ultimately, disentangling the relative effects of multiple factors on otolith chemistry and a detailed understanding of biomineralization is critical to the continued use of otoliths as natural tags for tracing fish movements and habitat use.     

锶对菠菜幼苗生长、光合和抗氧化酶活性的影响

为探究锶对植物生长生理的影响,以菠菜幼苗为试验材料,研究不同浓度(0、0.1、0.5和2.5 mmol·L^-1)锶处理对菠菜幼苗的叶片鲜重、叶片锶浓度、光合指标和抗氧化酶活性的影响。结果表明,0.1 mmol·L^-1 SrCl₂处理对菠菜幼苗生长和各项生理指标均未产生明显影响,叶片锶浓度在35 mg·kg^-1左右。0.5 mmol·L^-1 SrCl₂处理对菠菜幼苗生长表现为先促进后抑制;处理20 d后,抗氧化酶活性明显上升,丙二醛(MDA)、净光合速率(Pn)和叶片鲜重相较于对照组分别增加了24%和降低了15%、10%,叶片锶浓度达到318.33 mg·kg^-1。2.5 mmol·L^-1 SrCl₂处理下,植株生长受到明显抑制,抗氧化酶系统的响应更为强烈,处理20 d后MDA增加了68%,Pn和叶片鲜重分别降低了30%和48%,叶片锶浓度达到857.51 mg·kg^-1。综上,低浓度锶处理对菠菜生长未产生明显影响,但随着锶处理浓度的增加和胁迫时间的延长,植物生长受到的胁迫作用加剧。本研究为明确锶对菠菜生长生理的调控机理提供了理论依据。     

基于浸泡法的牙鲆耳石锶标记技术研究

为了探究耳石微化学标记技术在牙鲆增殖放流中的应用,以全长(1.56±0.16)cm的牙鲆幼鱼为研究对象,在其养殖水中分别添加0.5 mg/L、2 mg/L、8 mg/L、32 mg/L SrCl_2·6H_2O,以无添加SrCl_2·6H_2O组为对照组,人为改变牙鲆幼鱼生存环境中Sr~(2+)浓度72 h,研究不同浓度SrCl_2·6H_2O对牙鲆耳石锶标记效果。标记期间每24 h换水1次,换水量为50%,换水后补加SrCl_2·6H_2O至原始浓度,记录各浓度组标记期间及标记后的鱼苗死亡数量。利用X射线电子探针微区分析仪(EPMA)对耳石样本进行分析,定量线分析结果表明, 0.5 mg/L、2 mg/L SrCl_2·6H_2O浸染不能形成牙鲆耳石锶标记。8 mg/L浓度组出现Sr峰区, Sr/Ca (Sr:Ca×1000)均值为4.50～6.60, Sr峰值为5.49～8.49。32 mg/L浓度组Sr峰区均值为4.83～7.55, Sr峰值为5.62～11.04。这说明8 mg/L、32 mg/L SrCl_2·6H_2O可对牙鲆耳石进行锶标记。但8 mg/L浓度组出现未标记样本,且Sr峰区均值较32 mg/L浓度组低。32 mg/L浓度组Sr/Ca比值显著增高,即锶标记的Sr/Ca比值为6.61±0.86,与标记前和对照组Sr/Ca比值差异均显著(P0.05),锶标记率100%。面分布分析(mapping analysis)结果表明,从8 mg/L SrCl_2·6H_2O浓度组开始,耳石出现红色"高锶标记环",与耳石本底颜色对比明显,且随浓度升高,红色"高锶标记环"由浅变深,锶标记效果明显增强。单因素方差分析和Duncan多重比较结果显示,各浓度组全长、体重与对照组差异不显著(P0.05),不同浓度的SrCl_2·6H_2O对牙鲆幼鱼生长无影响。经χ2检验,各浓度组在浸泡标记期间死亡率及标记后养殖90 d的累积死亡率无显著性差异(P0.05),不同浓度的SrCl_2·6H_2O对牙鲆幼鱼死亡率无显著影响。因此, 32 mg/L SrCl_2·6H_2O为最佳标记浓度。     

Researches on Melting point and Viscosity of Mould Fluxes Containing SrO

The melting point and viscosity of SrO SiO 2 CaO Al 2O 3(5%) Na 2O(10%) CaF 2(10%) flux system have been measured,and the curve charts of the melting point and viscosity are drawn.Moreover,the mathematical relations of properties with chemical composition are founded.The best range of chemical composition for mould flux containing SrO is presented via analyzing the curve charts.     

Some effects of fly ash (from coal burning) on bush bean plants grown in solution culture

Abstract

Bush bean plants (Phaseolus vulgaris L. C. V. Improved Tendergreen) were grown for 14 days in 3700‐ml solution cultures with varying application rates of fly ash from a coal burning plant in California. Plants were also grown in a solution culture experiment in the presence of tiie chelating agent DTPA (diethylene triamine pentaacetic acid) and also in solutions acidified with HCl. The latter treatments were to determine if metals in the fly ash could be made more available to plants. The higher levels of fly ash (5 to 10 g/3700 ml) resulted in increased Ca, B, Si, Sr, and Ba in leaves, stems, and roots. No plants, however, appeared to have an excess of trace metals. In another experiment DTPA and HCl amendments failed to increase greatly the availability of trace metals from the fly ash in solution culture except for Zn. In this experiment the fly ash was the sole source of Ca and plants were deficient in Ca because insufficient fly ash was added. The fly ash resulted in increased Zn, Ca, Fe, Mn, B, Al, Si, Ti, Mo, Li, Sr, Ba in leaves, stems, and roots and increased V, Co, and Ni in roots. There was 3 to 4 μg/g Sn and 0.6 μg/g Be in the roots of plants grown with fly ash. In another experiment, fly ash supplied all the Ca necessary for plant growth without decreased yields resulting from any trace metal.     

Determination of strontium isotope ratio of brown rice for estimating its provenance

The strontium isotope ratio (⁸⁷Sr / ⁸⁶Sr) of brown rice (Oryza sativa L.) was determined by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in order to evaluate the values of ⁸⁷Sr / ⁸⁶Sr for use in the estimation of the area of rice production. Sample solutions were prepared from 5 g of rice samples using the acid (HNO₃-HClO₄-HF) digestion method. Removal of rubidium from the sample solutions was performed using ion-exchange resin (Dowex 50W X8). The Sr isotope ratios were determined with a precision of < 0.01% (RSD, repetitions = 60) by MC-ICP-MS. Typical analysis time for a single sample was about 15 min, reflecting the high sample throughput. The Sr isotope ratios of the Japanese rice samples ranged from 0.706 to 0.709. The Sr isotope ratios of the Chinese and Vietnamese rice samples (0.710 to 0.711) were slightly higher than those of almost all the Japanese samples. Australian rice showed the highest Sr isotope ratio (0.715 to 0.717) among all the rice samples examined. In contrast, the Sr isotope ratio of Californian rice (0.706) was lower than that of almost all the Japanese samples. The variation in the ⁸⁷Sr / ⁸⁶Sr ratios for the rice samples analyzed in this study clearly demonstrated that the Sr isotope ratios could provide a key information for the estimation of rice provenance.     

Effect of Long‐Term Fertilization on the Strontium Content of Soil

Abstract

The total and available strontium (Sr) contents of the experimental soil in the National Long‐Term Fertilization Trials set up in 1968 in Keszthely were compared in correlation to the Sr content of the Ramann‐type brown forest soil and different long‐term P‐fertilizer treatments. The Sr uptake by lettuce was also studied. Soil samples were taken from the 0‐ to 20‐cm depth in the 32nd year of the experiment from plots given different P fertilizer treatments (0–50–100–150–200 kg P₂O₅ ha^?1 y^?1). The total and available Sr content of soils were measured using ICP‐AES. A positive linear correlation was established between the total and available Sr contents of the experimental soils. The total and available soil Sr contents were significantly higher in large dose P‐fertilizer treatments than in case of lower doses. The Sr concentration of lettuce was four to eight times greater than the available Sr content of the soil samples, and Sr accumulation was observed in lettuce leaves.     

Sr2+在印度芥菜幼苗中的富集、亚细胞分布及贮存形态研究

为研究印度芥菜对Sr²⁺的富集、转运特性,解释超富集植物对Sr²⁺的解毒和富集机理,采用水培法培养印度芥菜幼苗至两片真叶,置于含锶[ρ(Sr²⁺)167(CK)~350 mg·L^-1]的营养液中处理7 d后取样,通过差速离心法和化学试剂提取法分离提取植物器官、细胞的亚细胞组分和不同化学形态的Sr²⁺,原子吸收分光光度法测定各器官(根、茎和叶)、各亚细胞组分及不同化学形态的Sr²⁺含量.结果显示:印度芥菜各营养器官对Sr²⁺的富集量为"叶> 茎> 根",地上部分含量占总含量的84.93%~90.46%,转移系数(TF)达到5.63~9.48;生物富集系数(BCF)达到8.21~12.34;各器官中Sr²⁺的亚细胞分布主要集中在细胞壁和可溶性组分中,相对含量达到95.62%~100%;细胞核、前质体、叶绿体和线粒体等细胞器仅含少量的Sr²⁺(<2.92%);Sr²⁺在印度芥菜根中主要以果胶酸盐、蛋白质结合态或吸附态存在,茎、叶中主要以水溶性有机酸盐和一代磷酸盐的形态存在.研究结果表明:质膜转运蛋白介导的跨膜运输是印度芥菜根系吸收Sr²⁺的主要途径,将Sr²⁺以结合态的形式富集到根部,再以水溶态的形式将Sr²⁺经茎部转运至叶中贮存;同时,通过细胞壁的阻滞作用,将Sr²⁺结合固定在细胞壁,并将进入细胞质基质的一部分Sr²⁺转运到液泡内,暂时或"永久性"存贮;通过区域化分布有效降低了细胞器、胞质溶胶(cytosol)及内含物中的Sr²⁺含量,极大地减缓了Sr²⁺对细胞器的功能性损伤,此为印度芥菜对耐受Sr²⁺胁迫的重要机理之一.     

Sawfish,read in tooth and saw: Rostral teeth as endogenous chemical records of movement and life-history in a critically endangered species

1. The ecology of endangered and rare species can be difficult to study owing to their low abundances and legal limits on scientist’s ability to catch, sample, and track them. This is particularly true of sawfish (family Pristidae), whose numbers have declined precipitously, placing all five species on the IUCN Red List of Threatened Species worldwide. Best known for their distinctive, toothed rostrum, the ecology, movement and life-history of sawfish are poorly understood.
2. Sawfish rostral teeth are modified placoid scales, which grow continuously throughout the life of the fish. This continuous growth, combined with their stable calcified makeup, makes sawfish rostral teeth a potential source of temporal records of chemical and isotopic changes through the life of the fish.
3. Rostral teeth are often preserved in museums and as curios, potentially providing a source of life-history data to inform conservation actions without the need for field study, or as an important compliment to it. This is the first study to recover temporally explicit chemical data from sawfish rostral teeth.
4. Using archived samples of largetooth sawfish (Pristis pristis) we show that multiple chemical tracers can be recovered from sawfish rostral teeth, and that these tracers can be used to understand movement across salinity gradients. We further show that sawfish rostral teeth contain repeated structures and indistinct banding which could potentially be used for ageing or growth analysis of fish.