不同流速下杂交鲟幼鱼游泳状态与活动代谢研究

为研究水流速度对杂交鲟幼鱼行为和代谢的影响,探讨游泳状态与活动代谢及相关游泳运动参数之间的关系,在26℃水温下,使用特制的鱼类游泳行为和活动代谢同步测定装置,测定了杂交鲟幼鱼在0.1、0.3、0.5 m/s三种流速和静水条件下的游泳状态、趋流率、摆尾频率和耗氧率。结果表明:随着流速的增大,杂交鲟幼鱼逆流前进和逆流静止游泳状态所占时间比例显著减少,而逆流后退所占时间比例显著增加,顺流而下时间比例有所上升。在0.0—0.3 m/s的流速范围内,杂交鲟幼鱼各个时段的平均趋流率、摆尾频率和耗氧率均随着流速的增加而增大,在0.3 m/s流速下分别达到100%﹑(2.53±0.34)Hz和(490.99±164.59)mg O2/(kg.h)。当流速增加至0.5 m/s时,在趋流率仍保持100%的情况下,其耗氧率相比0.3 m/s增加了21.86%,而摆尾频率却减小了6.70%。实验过程杂交鲟幼鱼趋流率与摆尾频率呈显著线性正相关,而摆尾频率与耗氧率在大部分时段却无相关性。随着时间的延长,各流速组杂交鲟幼鱼趋流率、摆尾频率和耗氧率呈现不同的变化趋势,其趋流率均相对稳定;但摆尾频率均随时间延长呈下降趋势,而耗氧率则在实验前9h随时间延长逐渐增加,随后趋于稳定。研究结果提示:杂交鲟幼鱼游泳状态的变化与流速有关,而反映运动强度大小的摆尾频率与活动代谢率的关系受到游泳状态的显著影响,同时也与运动代谢特征的时间变化有关。       

海水养殖杂交鲟的行为习性

对海水养殖条件下杂交鲟的行为习性进行观察.结果表明,杂交鲟对干露的耐受力较强,干露1 h存活率100%,干露3 h存活率74.1%;食性可以驯化,能以全植物性蛋白源为饲料,耐饥饿能力强;摄食节律明显,在水泥池内养殖形成早晨、傍晚两个摄食高峰,深水网箱养殖在接近早晨、傍晚的平潮或停潮时间内形成两个摄食高峰,在这两个摄食高峰的摄食量超过日摄食总量的50%;水泥池养殖的杂交鲟具有昼伏夜出习性,深水网箱养殖的杂交鲟流急时在网箱底部活动、流缓时到水层中游动;杂交鲟抗流速、抗波浪能力较美国红鱼差、较大黄鱼强.杂交鲟能较快适应海水养殖环境,放入深水网箱养殖的杂交鲟规格宜在400 g左右.     

低氧胁迫和恢复对杂交黄颡鱼“黄优1号”肠道组织的影响

为探究低氧胁迫和恢复对杂交黄颡鱼(Pelteobagrus fulvidraco) “黄优1号”肠道组织的影响, 研究运用酶活测定、HE染色、qRT-PCR、TUNEL检测及16S rRNA测序技术等方法, 分析低氧胁迫[(1.0±0.1) mg/L]和恢复下[(7.0±0.5) mg/L]该鱼肠道氧化应激指标、组织结构形态、细胞凋亡及微生物组成变化。结果显示: (1)在低氧胁迫下肠道中抗氧化酶活性(SOD、CAT、GSH-Px)、能量代谢酶活性(LDH)、丙二醛(MDA)和脂质过氧化物(LPO)含量显著升高, 恢复溶氧后氧化应激反应也比较剧烈。(2)低氧胁迫阶段, 肠道组织受损现象逐渐加剧, 杯状细胞肿胀、黏膜层被侵蚀, 恢复溶氧24h后, 缺氧引起的生理变化并未得到明显改善。(3)肠道组织细胞凋亡程度随着低氧时间的延长而加剧, 凋亡相关基因(bax、caspase9和p53)的表达量显著升高, bcl-2基因的表达量则减少。(4)低氧胁迫阶段肠道微生物相对丰度降低, 低氧胁迫72h的处理组中以厚壁菌门(Firmicutes)(47.8%)和拟杆菌门(Bacteroidetes)(40.6%)的丰度最为优势, 恢复溶氧后肠道菌群数量有所增加; KEGG功能预测显示, 多数肠道微生物与代谢通路相关。研究结果可为解析低氧和恢复下杂交黄颡鱼“黄优1号”肠道组织内环境稳态调控机制提供理论依据。     

肠道微生物及其代谢产物与宿主脂质代谢研究进展

近年来,肠道微生物与宿主脂质代谢研究受到国内外的广泛关注.首先,肠道微生物多样性和组成在脂肪代谢紊乱动物模型、肥胖患者中均发生显著改变,而利用粪菌移植、益生菌以及营养干预重塑肠道菌群结构可以调控宿主脂质代谢.本文重点介绍了肠道微生物与宿主脂代谢的联系,并从短链脂肪酸、胆汁酸、氨基酸、内毒素和微生物节律等方面探讨了肠道微生物调控宿主脂代谢的潜在机制,以期为脂质代谢引起的疾病提供干预靶点.     

饥饿胁迫对多刺裸腹溞糖与蛋白质代谢的影响

研究了饥饿24 h和48 h对多刺裸腹溞Moina macrocopa糖和蛋白质代谢中间代谢产物以及主要代谢酶的影响.结果显示,饥饿能够显著影响多刺裸腹溞机体内葡萄糖、丙酮酸、总町溶性蛋白和总氨基酸含量;同时对琥珀酸脱氢酶(SDH)、丙酮酸激酶(PK)、谷丙转氨酶(GPT)和谷草转氨酶(GOT)的活力也有不同程度的影响.饥饿24 h和48 h,葡萄糖含量分别降低了32.17%和37.55%;丙酮酸含量分别降低了46.04%和38.53%,与对照组相比.发生了显著性变化(P<0.05).饥饿24 h可溶性蛋白含量降低了32.14%(P<0.05);饥饿24 h和48 h总氨基酸含量呈极显著下降趋势(P<0.01),分别下降了61.47%和65.38%.实验证明,饥饿胁迫可诱导SDH活力增加,48 h时活力极显著升高(P<0.01);而PK活力变化不显著(P>0.05);GPT和GOT两种转氨酶活性在饥饿胁迫下呈上升趋势,但是与对照组相比无显著性差异(P>0.05).     

禁食对草鱼不同组织、器官蛋白质代谢的影响

采用肌肉注射、以3H标记的亮氨酸作为示踪氨基酸的大剂量方法、茚三酮测定氨基酸总量的方法,测定了摄食和禁食45 d的草鱼(Ctenopharyngodon idellus)各组织、器官游离氨基酸量、吸收积累的试验氨基酸量、非蛋白质水溶液和蛋白质结合的放射性强度(dpm值)。结果表明,肌肉是草鱼蛋白质代谢最为活跃的组织,禁食使其蛋白质合成量下降了38%左右;脑保持着较高的、稳定的蛋白质代谢活动,其新的蛋白质合成量没有受到禁食的影响;肾脏积累了较多的游离形式的试验氨基酸,禁食并没有使其蛋白质合成量下降,反而有少量增加;肠道是蛋白质代谢活跃的内脏器官,禁食使其蛋白质合成量显著减少,仅为摄食组的30%左右;脾脏进行着较为活跃的蛋白质代谢,禁食45 d后脾脏非蛋白质水溶液和蛋白质结合的dpm值均较摄食组增加了161%,其新合成的蛋白质量为摄食条件下的2.6倍;禁食并没有使肝胰脏蛋白质合成量受到影响;心脏也进行着较为活跃的蛋白质代谢,禁食使其新的蛋白质合成量降低了一半左右。通过氨氮排泄率和排泄氨氮占体蛋白质氮百分比的分析结果,草鱼在禁食过程中整体蛋白质代谢活动在5 d以前快速下降,氨氮排泄率从第3 d的404.44μmol(N)/kg.h下降到第5 d的325.68μmol(N)/kg.h,5 d以后氨氮排泄率趋于稳定(水温在21.5℃),此时草鱼的氨氮排泄率为4.56 mg/kg.h、氨氮排泄的氮占鱼体蛋白质的百分比为0.37%,可以作为草鱼内源性氨氮的排泄参考值。     

斑点叉尾和杂交鲟幼鱼昼夜摄食节律和胃肠排空时间的研究

采用一次饱食投喂(将一昼夜分为8个时间段,每个时间段作为一个处理组,每天每个处理组饱食投喂一次)和分段式连续投喂(将一昼夜分为8个时间段,每天每个实验缸连续投喂8次)两种方法研究斑点叉尾和杂交鲟幼鱼的昼夜摄食节律,同时研究它们在摄食后24h内胃和全肠的排空时间。结果显示,在两种投喂方式下,斑点叉尾均表现出24h 一周期的摄食节律,两个日摄食率高峰值均出现在06：00和18：00(P<0.05)。杂交鲟在一次饱食投喂下表现出24h一周期的摄食节律,高峰值分别出现在11：00、17：00和05：00,在分段式连续投喂时表现出48h 一周期的摄食节律,高峰值分别出现在11：00、17：00和36：00。在摄食后1-9h 内,斑点叉尾的胃内含物比率急剧降低(P<0.05),并在24h 时出现极低值(P<0.05),而1-9h 内全肠内含物比率迅速升高(P<0.05),在9h时达到最大(P<0.05),在24h出现极低值(P<0.05)。在摄食后1-7h内,杂交鲟的胃内含物比率迅速下降(P<0.05),在24h 时出现极低值(P<0.05),1-7h 内肠内含物比率迅速升高(P<0.05),24h 时呈现极低值(P<0.05)。结果表明,两种实验鱼表现出不同的昼夜摄食节律,该节律受各自胃肠排空时间的影响,也受投喂时间的影响。研究建议,在斑点叉尾和杂交鲟幼鱼的养殖中宜在光线较弱的清晨(05：00-06：00)和黄昏(17：00-18：00)进行投喂。     

摄食和饥饿对大口黑鲈游泳运动能力和低氧耐受的影响

为了研究摄食和饥饿对鱼类游泳运动能力和低氧耐受的影响; 以大口黑鲈(Micropterus salmoides)为对象, 在25℃下, 测定对照组(禁食2d)、摄食组(摄食后3h)和饥饿组(禁食16d)实验鱼的日常代谢率(RMR)、活跃代谢率(AMR)、代谢范围(MS)、临界游泳速度(U_crit)、临界氧压(P_crit)和失去平衡点(LOE)。研究显示摄食后实验鱼RMR显著提升, AMR没有显著变化, 而MS和U_crit显著下降(P<0.05); 饥饿后实验鱼RMR、AMR和MS均没有显著变化, 而U_crit显著下降(P<0.05); 摄食后实验鱼P_crit显著上升, 溶解氧(DO)高于P_crit时的代谢率(MR)与DO之间的关系的斜率显著大于对照组所对应的斜率, 而LOE没有变化(P<0.05); 饥饿后实验鱼P_crit和LOE均没有显著变化, 而DO 低于P_crit时的MR与DO之间的关系的斜率显著小于对照组所对应的斜率(P<0.05)。结果表明, 摄食削弱大口黑鲈游泳运动能力是因为“心鳃”系统对其有氧代谢能力的限制; 饥饿后大口黑鲈游泳运动能力下降可能与其无氧代谢能力下降相关; 摄食削弱大口黑鲈的低氧耐受, 而饥饿后其低氧耐受有所增强, 但大口黑鲈低氧耐受总体趋于保守。     

肠道微生物调控宿主食欲的研究进展

肠道微生物与宿主代谢相互作用,可调节机体的生理功能。宿主机体中存在"微生物-肠道-大脑轴",肠道菌群可通过多种途径影响中枢神经系统,进而对宿主摄食等行为产生影响。食物中不易被宿主消化吸收的膳食纤维等营养物质,被肠道微生物发酵可产生多种代谢产物,这些代谢产物作为信号分子可通过不同途径介导中枢神经系统,进而调控宿主食欲。本文主要综述了肠道微生物及其代谢产物对中枢神经系统与宿主食欲的影响及其可能的调控途径与机制,以加深肠道微生物在调控宿主食欲方面的新认识。     

黄土高原石油污染土壤微生物群落结构及其代谢特征

针对污染胁迫下土壤微生物群落变化和代谢变异等问题,基于平板稀释法和Biolog微平板分析方法,研究了陕北黄土高原石油污染土壤微生物群落结构、代谢特征及其功能多样性。结果表明,不同类群的土壤微生物对石油污染胁迫的响应不同,污染土壤细菌和真菌数量高出清洁土壤1个数量级,而污染土壤的放线菌数量极显著减少(P0.01);污染土壤和清洁土壤微生物对糖类和多聚物类碳源较易利用,污染土壤微生物总体上代谢碳源的种类和活性均低于清洁土壤。微生物群落主成分分析(PCA)表明,石油污染土壤和清洁土壤的微生物群落存在显著差异(P0.01),起分异作用的碳源主要为糖类,其次是羧酸类和氨基酸类;随着土壤石油含量增加,典型变量值变异(离散)增大,土壤微生物群落结构稳定性降低。微生物群落多样性分析表明,Shannon丰富度指数(H)、McIntosh均一度指数(U)和Simpson优势度指数(1/D)均达到极显著差异(P0.01),污染土壤微生物群落H和U低于清洁土壤,但是一定浓度的石油污染可以刺激土壤微生物群落中优势种群的生长,1/D增高。研究结果为陕北黄土高原石油污染区土壤微生物修复提供理论基础。     

Ontogenetic Behavior, Migration, and Social Behavior of Pallid Sturgeon, Scaphirhynchus albus, and Shovelnose Sturgeon, S. platorynchus, with Notes on the Adaptive Significance of Body Color

We conducted laboratory studies on the ontogenetic behavior of free embryos (first life interval after hatching) and larvae (first feeding interval) of pallid and shovelnose sturgeon. Migration styles of both species were similar for timing of migration (initiation by embryos on day 0 after hatching and cessation by larvae on days 12–13 at 236–243 cumulative temperature degree units), migration distance (about 13km), life interval when most distance was moved (embryo), and diel behavior of embryos (diurnal). However, the species differed for two behaviors: movement characteristics of embryos (peak movement rate of pallid sturgeon was only one-half the peak rate of shovelnose sturgeon, but pallid sturgeon continued the lower rate for twice as long) and diel behavior of larvae (pallid sturgeon were diurnal and shovelnose sturgeon were nocturnal). Thus, the species used different methods to move the same distance. Migrating as poorly developed embryos suggests a migration style to avoid predation at the spawning site, but moving from spawning habitat to rearing habitat before first feeding could also be important. Migrants of both species preferred bright habitat (high illumination intensity and white substrate), a behavioral preference that may characterize the migrants of many species of sturgeon. Both species were remarkably similar for swimming height above the bottom by age, and day 7 and older migrants may swim far above the bottom and move far downstream. A migration of 12 or 13 days will probably not distribute larvae throughout the population's range, so an older life interval likely initiates a second longer downstream migration (2-step migration). By day 2, individuals of both species were a black-tail phenotype (light grey body with a black-tail that moved conspicuously during swimming). Aggregation behavior suggests that black-tail is a visual signal used for group cohesion.     

玫瑰高原鳅肠道微生物多样性研究

研究旨在分析玫瑰高原鳅(Triplophysa rosa)肠道微生物的结构组成和多样性, 探索其肠道微生物的潜在功能。提取了5尾玫瑰高原鳅的肠道总DNA, 运用Illumina Miseq平台对肠道微生物16S rRNA的V3—V4区进行了测序, 统计样品肠道微生物的操作分类单元(Operational Taxonomic Units, OTUs)数量, 分析物种组成、丰度及Alpha多样性, 并预测肠道微生物的功能。结果显示, 玫瑰高原鳅的肠道微生物有19门、31纲、87目、 146科、253属、 320种, 451个OTUs。在门水平上, 优势菌群为变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroidetes); 在属水平上, 优势菌群为气单胞菌属(Aeromonas)、爱德华菌属(Edwardsiella)、邻单胞菌属(Plesiomonas)和希瓦氏菌属(Shewanella)。功能预测表明, 肠道微生物编码的大多数基因与新陈代谢相关, 其中“碳水化合物运输和代谢”和“氨基酸转运与代谢”功能类群的相对丰度较高。玫瑰高原鳅肠道内微生物组成复杂, 其功能分析有助于理解肠道微生物对玫瑰高原鳅摄食的影响, 为进一步研究玫瑰高原鳅的食性提供了理论基础。     

Water temperature, light intensity and zooplankton density and the feeding activity of juvenile brook charr (Salvelinus fontinalis)

SUMMARY 1. The objective of this study was to evaluate the effects of zooplankton biomass (as a measure of density), fish biomass, light intensity and water temperature on the attack rate and swimming characteristics (i.e. swimming speed and angle of turn) of juvenile (1+) brook charr (Salvelinus fontinalis) in field enclosures. We used a portable underwater camera system in a series of pelagic enclosures to quantify the feeding behaviour of brook charr over a gradient of natural conditions. 2. In simple linear or non‐linear regression models we found (i) that attack rate and angle of turn were positively related to water temperature, (ii) that attack rate and swimming speed were positively related to zooplankton biomass and light intensity and (iii) that attack rate was positively related to swimming speed. In multiple regression models, fish biomass, light intensity and variance of the angle of turn accounted for 87% of the variation in attack rate. Light intensity and water temperature accounted for 86% of the variation in swimming speed. Fish gut fullness and attack rate accounted for 83% of the variation in the variance of the angle of turn executed by fish. 3. The increase in the number of attacks as zooplankton biomass increases conforms to the general positive functional response observed in other fish species. Our results also support the hypothesis that swimming speed increases with prey biomass. We did not observe a plateau in attack rate as zooplankton biomass increased. As our experiments were performed under natural biotic and abiotic conditions, factors other than zooplankton biomass might affect or limit this response, such as water temperature and light intensity. 4. Because zooplankton biomass was correlated with water temperature and light intensity, it was not possible to evaluate the independent contribution of these factors on the attack rate and swimming characteristics (swimming speeds and angle of turn) of brook charr. However, this study highlighted the impact of these factors on the feeding behaviour of juvenile brook charr when feeding in the pelagic habitat under natural conditions, and their importance in future models of optimal foraging and fish habitat quality.     

The effects of substrate composition on foraging behavior and growth rate of larval green sturgeon, Acipenser medirostris

We investigated the effects of substrate composition on foraging behavior and growth rate of larval green sturgeon, Acipenser medirostris, in the laboratory at 20±1°C over a period of 5 weeks. Larval groups (n=100) with mean wet weight (0.72±0.01 g) at 50 days post-hatch were reared on slate-rocks, cobble, sand or glass. Typically, fish were negatively rheotactic and exhibited dispersed skimming behaviors on provided substrates during pre-feeding and feeding, respectively, but were all positively rheotactic during feeding. Fish reared on slate-rock substrates were negatively phototactic, remained benthic, and aggregated underneath the substrates. In all substrates except slate-rocks, fish displayed frequent episodes of burst and glide swimming activity, tank wall skimming and vertical swimming behaviors, however these behaviors ceased immediately during feeding and reappeared at the end of the feeding period. Substrate composition led to variable foraging effectiveness and likely contributed to significant differences in specific growth rates (2.28, 1.14, 1.77, and 2.27% body weight per day) and mortality (7%, 40%, 11%, 0%) among the treatment groups; slate-rocks, cobble, sand, and glass, respectively. There were no significant differences in morphometrics, somatotopic indices, and whole-body lipid content among treatment groups at the end of the experiment. The present findings indicate that certain substrates in artificial/natural habitats may negatively affect larval growth and may lead to decreased recruitment of juvenile green sturgeon in the wild.     

基于中华鲟繁殖群体数量的长江中、下游生态环境考核指标

繁殖群体数量是中华鲟能否成功繁殖的重要影响因子, 建议作为长江生态考核的重要评价指标。根据重要种群参数和历史数据, 基于稳态转换理论和方法, 确定中华鲟繁殖群体数量指标的评估基准值和等级, 670尾以上为“优”、400—670尾为“良”、200—400尾为“中”、50—200尾为“差”、50尾以下为“极差”。水声学探测结果显示, 1998—2001年中华鲟繁殖群体数量指标评级为“良”; 2004—2012年三峡工程蓄水后至向家坝蓄水前评级为“中”; 2013—2020年评级为“极差”。为了复壮中华鲟野生种群, 建议修复葛洲坝下中华鲟产卵场功能, 大规模放流性成熟亲鱼和大规格个体, 建立国家级中华鲟保育中心。     

The effects of substrate composition on foraging behavior and growth rate of larval green sturgeon, Acipenser medirostris

We investigated the effects of substrate composition on foraging behavior and growth rate of␣larval green sturgeon, Acipenser medirostris, in the␣laboratory at 20±1°C over a period of 5 weeks. Larval groups (n = 100) with mean wet weight (0.72 ± 0.01 g) at 50 days post-hatch were reared on slate-rocks, cobble, sand or glass. Typically, fish were negatively rheotactic and exhibited dispersed skimming behaviors on provided substrates during pre-feeding and feeding, respectively, but were all positively rheotactic during feeding. Fish reared on slate-rock substrates were negatively phototactic, remained benthic, and aggregated underneath the substrates. In all substrates except slate-rocks, fish displayed frequent episodes of burst and glide swimming activity, tank wall skimming and vertical swimming behaviors, however these behaviors ceased immediately during feeding and reappeared at the end of the feeding period. Substrate composition led to variable foraging effectiveness and likely contributed to significant differences in specific growth rates (2.28, 1.14, 1.77, and 2.27% body weight per day) and mortality (7%, 40%, 11%, 0%) among the treatment groups; slate-rocks, cobble, sand, and glass, respectively. There were no significant differences in morphometrics, somatotopic indices, and whole-body lipid content among treatment groups at the end of the experiment. The present findings indicate that certain substrates in artificial/natural habitats may negatively affect larval growth and may lead to decreased recruitment of juvenile green sturgeon in the wild.     

Dietary phosphorus affected growth performance,body composition,antioxidant status and total P discharge of young hybrid sturgeon (♀Huso huso × ♂Acipenser schrenckii) in winter months

An 8‐week feeding trial was carried out using young hybrid sturgeon (♀Huso huso × ♂Acipenser schrenckii) to study the effects of dietary phosphorus (P) on growth performance, body composition, liver and serum antioxidant status as well as the effluent P content in the wintertime. Four puffed pellet diets were formulated to contain graded total P levels at 0.63, 1.15, 1.85, and 2.12%, respectively. Triplicate groups of hybrid sturgeon (494.21 ± 18.63 g) were reared in concrete ponds (2.0 × 1.2 × 1.4 m), and fed one of the four diets for 8 weeks. Weight gain and feeding rate significantly decreased with increasing dietary P content, and fish fed the 2.12% P diet had negative growth. With the increase in dietary P, whole body ash and P content significantly increased. There was no inverse relationship between the whole body lipid content and dietary P level in young hybrid sturgeon. Hybrid sturgeon liver exhibited higher superoxide dismutase, catalase and glutathione peroxidase activities in the 0.63 and 1.15% dietary P treatment groups than those in the other two groups. Serum alkaline phosphatase activity increased significantly with increasing dietary P. Discharge of P into the pond increased significantly with increasing dietary P. In conclusion, a dietary P content between 0.63 and 1.15% helped young hybrid sturgeon to activate their antioxidant defense system and eradicate the free radicals, in order to reduce the antioxidant damage, while still keeping total P content in the pond at a relatively low level during the winter months.     

Environmental noise reduces predation rate in an aquatic invertebrate

Noise is one of a wide range of disturbances associated with human activities that have been shown to have detrimental impacts on a wide range of species, from montane regions to the deep marine environment. Noise may also have community-level impacts via predator–prey interactions, thus jeopardising the stability of trophic networks. However, the impact of noise on freshwater ecosystems is largely unknown. Even more so is the case of insects, despite their crucial role in trophic networks. Here, we study the impact of underwater noise on the predatory functional response of damselfly larvae. We compared the feeding rates of larvae under anthropogenic noise, natural noise, and silent conditions. Our results suggest that underwater noise (pooling the effects of anthropogenic noise and natural noise) decreases the feeding rate of damselflies significantly compared to relatively silent conditions. In particular, natural noise increased the handling time significantly compared to the silent treatment, thus reducing the feeding rate. Unexpectedly, feeding rates under anthropogenic noise were not reduced significantly compared to silent conditions. This study suggests that noise per se may not necessarily have negative impacts on trophic interactions. Instead, the impact of noise on feeding rates may be explained by the presence of nonlinearities in acoustic signals, which may be more abundant in natural compared to anthropogenic noise. We conclude by highlighting the importance of studying a diversity of types of acoustic pollution, and encourage further work regarding trophic interactions with insects using a functional response approach.