Differential piscivory of the native Percichthys trucha and exotic salmonids upon the native forage fish Galaxias maculatus in Patagonian Andean lakes

The present paper analyses predation patterns, of Percichthys trucha and salmonid fish upon Galaxias maculatus in five lakes of northern Patagonia with differing community and environmental characteristics. Tank experiments were performed to evaluate relative efficiency of native and exotic predators of G. maculatus under treatments with and without cover (aquatic vegetation). Important differences were found between predators with regards to distribution and consumption of G. maculatus. Salmonids are more efficient than P. trucha in consuming G. maculatus in deep environments with scarcely vegetation; in contrast to native species they frequently use the pelagic environment. Although pelagic habitat might have served in the past as a refuge from native predators in the past, G maculatus now experiences intense predation in the pelagic zone by exotic salmonids. It is suggested that the widespread distribution of G. maculatus in Patagonian lakes may have facilitated the success of salmonids throughout Patagonia.     

Effects of some environmental parameters on the reproduction and development of a tropical marine harpacticoid copepod Nitocra affinis f. californica Lang

The effects of salinity, temperature, and light conditions on the reproduction and development of harpacticoid copepod, Nitocra affinis f. californica under controlled laboratory conditions were determined. Seven different salinity levels (5, 10, 15, 20, 25, 30, 35 ppt), four temperatures (20, 25, 30, 35 °C), three different light intensities (25, 56, 130 μmol m⁻² s⁻¹) and photoperiods (24 h:0 h, 1 h:23 h, 12 h:12 h LD cycle) were employed in this study. The highest (p < 0.05) overall reproduction and fastest development time were achieved by copepods reared under 30–35 ppt salinity. The optimum temperature required for the maximum reproduction was 30 °C while under 30 °C and 35 °C the copepod development time was shortest (p < 0.05) compared to other temperature levels. The overall reproduction was highest (p < 0.05) and development rate of N. affinis was shortest (p < 0.05) under lowest light intensity (25 μmol m⁻² s⁻¹). Continuous light (24 h:0 h LD) inhibited the egg production while, continuous darkness (1 h:23 h LD) and 12 h:12 h LD significantly favoured the overall reproductive activity of the female. Photoperiods 1 h:23 h and 12 h:12 h LD yielded highest total (p < 0.05) offspring female⁻¹ coupled with highest (p < 0.05) survival percentage. This study illustrated that although N. affinis can tolerate wide range of environmental conditions, prolonged exposure to subnormal environments affect its reproduction and development. This study showed that this species can be mass cultured for commercial purposes and has a potential to be used for toxicity studies due to its high reproductive performance fast development and a wide range of tolerance to environmental conditions.     

五个湖泊中华刺鳅(Mastacembelus sinensis)种群线粒体细胞色素b遗传多样性分析

采用特异性引物对中华刺鳅基因组DNA进行扩增和测序,获得了江苏省5个湖泊的中华刺鳅种群线粒体cyt b基因767 bp的序列.分析表明,cyt b基因中A+T含量略高于G+C含量,144个中华刺鳅共获得cyt b基因单倍型28个,变异位点38个,其中单倍型Hap1分布最为广泛,可能为祖先型单倍型.平均单倍型多样性和平均核苷酸多样性指数分别为0.58751和0.00214,遗传多样性较低.群体间遗传分化系数为0.0356,绝大多数的遗传变异都来自群体内部,而群体间的遗传分化极小.构建的系统进化树未出现明显的以单个湖泊群体的聚簇,5个湖泊的种群间基因交流极其强烈.研究结果表明,当前5个湖泊的中华刺鳅遗传多样性水平比较低,亟待加强保护.     

Cloning and developmental expression of kinesin superfamily7 (kif7) in the brackish medaka (Oryzias melastigma), a close relative of the Japanese medaka (Oryzias latipes)

kif7 is a member of the kinesin superfamily members which are molecular motor proteins that move along microtubules in a highly regulated manner through ATP hydrolysis. In this paper, we report on the cloning of the Oryzias melastigma kif7 (omkif7) using primers designed according to the Japanese medaka (Oryzias latipes) database. The cloned omkif7 has an open reading frame of 3762bp and is deduced to encode a polypeptide of 1254 amino acids that possesses the putative ATP-binding and microtubule-binding motifs in its motor domain at the N-terminal region. We characterized the cloned omkif7 by comparison with the zebrafish kif7. Both omkif7 and zebrafish kif7 are shown to be expressed in all embryonic stages and adult tissues examined with higher expression level in the testis and ovary. Whole-mount in situ hybridization revealed that the expression of omkif7 is ubiquitous during the early stages of embryonic development, but became more restrictive and localized to the brain, fin bud and eye at later development. This study suggested that the brackish O.melastigma can serve as a good seawater model organism for developmental studies by utilizing the resources developed from its close relative of the Japanese medaka.     

基质类型对耳萝卜螺(Radix auricularia)-苦草(Vallisneria spiralis)牧食关系的影响

沉水植物和螺类都是水生生态系统的重要组成部分,两者的牧食关系也是水生食物网中重要的一环,而不同的基质类型可能会影响两者的生长和改变沉水植物对螺类牧食的防御策略.以耳萝卜螺（Radix auricularia）和苦草（Vallisneria spiralis）为对象,研究基质类型、螺类牧食对沉水植物的生长及防御策略的影响,以及基质类型及沉水植物对螺类生长和生理特征的影响.研究发现,螺类牧食和基质类型对苦草生长和元素特征具有显著的影响,存在螺类牧食时,泥沙基质和沙基质苦草的相对生长速率显著降低,泥沙、沙和泥基质苦草地上生物量分别减少了67.74%、58.58%和17.84%,根冠比分别升高了177.51%、217.23%和1.44%;且泥沙基质中苦草的叶片数显著低于无牧食组.不同基质类型下,牧食对苦草总碳含量无显著影响,但泥和泥沙组中,螺类牧食使苦草的总氮含量均显著降低,碳氮比均显著升高;沙基质下,螺类牧食使苦草总酚含量显著降低.基质类型对螺类的形态特征（除壳宽外）、生长及元素含量均无显著影响.总体来看,基质类型对耳萝卜螺牧食和苦草防御策略具有一定程度的影响,但对螺类的生长及元素特征基本无影响.本研究可以为牧食理论的研究提供基础数据支持,也可为沉水植被恢复、水生生态系统稳定提供参考,但基质类型对螺草牧食关系的长期影响,仍需进一步深入研究.     

河蚬(Corbicula fluminea)对霍甫水丝蚓(Limnodrilus hoffmeisteri)生物扰动的抑制效应

近年来太湖局部区域水体富营养化仍有加剧趋势,这可能与底栖动物生物扰动促进沉积物营养盐释放有关.耐污种霍甫水丝蚓(Limnodrilus hoffmeisteri)与常被用于生态修复的河蚬(Corbicula fluminea)均为太湖底栖动物优势种类,本文设计了双因素4组处理(对照组、河蚬组、霍甫水丝蚓组和混合组(霍甫水丝蚓和河蚬))的室外受控实验,研究在太湖2种种群分布交错区,河蚬能否对霍甫水丝蚓的生物扰动产生抑制效应.结果表明:霍甫水丝蚓扰动能显著增加水体总氮、总磷浓度,同时促进浮游植物生长;河蚬通过滤食和生物沉降作用显著降低水体总氮、总磷和悬浮物浓度,抑制浮游植物生长,从而促进了底栖藻类的生长;河蚬对霍甫水丝蚓生物扰动效应有抑制作用.     

外来种福寿螺(Pomacea canaliculata)对3种沉水植物的牧食偏好及水体理化因子的响应

外来种福寿螺(Pomacea canaliculata)相较我国本土螺类其牧食量更大且繁殖速度更快,对栖息地水生植物的现存量和实施水生植被恢复的生态治理工程的成功性可能构成威胁,目前对福寿螺影响浅水湖泊沉水植物的重建缺乏足够的研究.本文通过设置不同沉水植物种类组合系统,研究福寿螺对3种常用于浅水富营养化湖泊治理的沉水植物密刺苦草(Vallisneria denseserrulata)、轮叶黑藻(Hydrilla verticillata)、穗花狐尾藻(Myriophyllum spicatum)的牧食偏好以及不同植物配置系统理化因子的响应变化,结果表明福寿螺对沉水植物植株附着偏好为密刺苦草轮叶黑藻穗花狐尾藻,而牧食破坏强度为轮叶黑藻穗花狐尾藻密刺苦草,轮叶黑藻最容易受到福寿螺牧食影响而快速消亡,穗花狐尾藻叶片也会被全部牧食仅剩下茎,而苦草存活受到的影响较小.福寿螺会导致轮叶黑藻+密刺苦草组合系统中总氮、氨氮、总磷、正磷酸盐浓度显著升高,而密刺苦草+穗花狐尾藻组合中总磷、正磷酸盐浓度显著升高,但是在轮叶黑藻+穗花狐尾藻组合中仅总氮浓度显著升高.研究表明福寿螺能够影响沉水植物间的竞争关系,但是3种沉水植物均不能阻止福寿螺的牧食;福寿螺牧食会显著降低沉水植物生物量,最终会影响草型清水态系统的稳定性.     

Isolation and characterization of Aeromonas species from an eutrophic tropical estuary

Isolation and characterization of Aeromonas species were undertaken in the Ebrié lagoon (Abidjan, Côte d’Ivoire) over a one year period. Overall 63% of 501 water samples were identified as positive for Aeromonas spp. A. sobria, A. hydrophila and A. caviae represent respectively 49.20%, 20.63% and 30.15% of the positive samples. Thirty nine of the positive samples were recovered from surface water samples; while 24 bottom water samples were positive for Aeromonas. Aeromonas species are most frequently (82.53) present in the Ebrié lagoon urban area during the rainy and flood seasons when the salinity is low and below 10‰. A lower isolation frequency is noticed during the dry season when water salinity is over 10‰. Finally, a higher isolation frequency occurred in samples with highest counts of Escherichia coli.     

冬、春季芦苇(Phragmites australis)和狭叶香蒲(Typha angustifolia)的腐解过程及其对水质的影响

水生植物修复已经成为水体富营养化修复的重要手段,但其周期性的衰亡也给水体带来不容忽视的负效应.以府河流域丘陵地带农业区小水系自然生长的芦苇(Phragmites australis)和狭叶香蒲(Typha angustifolia)为研究对象,通过模拟实验,研究其冬季和春季腐烂分解过程的差异以及对水体营养盐水平的影响.结果表明,2种挺水植物的剩余干物质量整体上都呈现先快速下降再缓慢下降的趋势,芦苇和狭叶香蒲春季的分解速率分别为0.0251和0.0169 d~(-1),分别明显高于冬季分解速率(0.0027和0.0052 d~(-1));且腐烂分解速率与植物初始氮磷含量和氮磷比都有一定相关性.2种植物在冬季和春季磷的矿化速率都明显高于氮的矿化速率.实验水体的总氮和总磷浓度在腐解过程呈现初期迅速上升、中期迅速下降、后期缓慢下降的趋势.总体来看,芦苇和狭叶香蒲的腐烂分解受季节和初始氮磷浓度的影响较大,芦苇反应较香蒲更敏感且对水质的影响具有时效性.     

铁对拟柱孢藻(Cylindrospermopsis raciborskii)和角星鼓藻(Staurastrum spp.)季节动态和生长的影响——以广东大沙河水库为例

拟柱孢藻（Cylindrospermopsis raciborskii）和角星鼓藻（Staurastrum spp.）是热带亚热带浮游植物群落中的常见优势种类,为了解铁对2种浮游植物季节动态和生长的影响,本文通过对典型热带水库的野外调查,分析铁与2种藻生物量和相对生物量的季节动态的关系,并通过室内实验分别以无机磷（KH₂PO₄）和有机磷（C₆H₁₃O₉P）为磷源,比较3种铁浓度（0.029、0.29和0.689 mg/L）下拟柱孢藻（C.raciborskii,N8）和角星鼓藻（Staurastrum sp.,FACHB-1449）的比生长速率、铁载体产量和碱性磷酸酶活性的差异.结果显示,拟柱孢藻和角星鼓藻是浮游植物群落的主要优势种类,两者的生物量最大占到总生物量的82%以上;两者对环境变量响应的区别主要体现在对溶解性铁浓度变化的响应差异上,拟柱孢藻生物量与溶解性铁有显著的线性回归关系,但角星鼓藻的生物量与铁没有显著线性回归关系.室内实验中,拟柱孢藻N8的比生长速率在无机磷源铁浓度为0.689 mg/L条件下最大,为0.098±0.01 d^-1,2种磷源条件下比生长速率均随铁浓度降低而显著降低,6个实验组均检到铁载体：6个实验组角星鼓藻FACHB-1449的比生长速率没有明显差异,平均为0.079±0.001 d^-1,均未检出铁载体,磷源和铁浓度对其比生长速率的影响不显著;有机磷源条件下,拟柱孢藻N8实验组碱性磷酸酶活性均显著高于角星鼓藻FACHB-1449实验组,拟柱孢藻N8实验组酶活性随铁浓度降低而显著降低,但角星鼓藻FACHB-1449各实验组的碱性磷酸酶活性无明显差异.以上结果表明,水体中溶解性铁的供应对拟柱孢藻的种群动态和优势有重要作用,与角星鼓藻相比,拟柱孢藻的生长更易受到铁的限制,尤其在无机磷缺乏、磷源主要以有机磷形式供应时,铁对拟柱孢藻生长的限制作用增强.     

光照强度对铜绿微囊藻(Microcystis aeruginosa)和斜生栅藻(Scenedesmus obliqnus)生长及吸收特性的影响

在不同的光照强度下,测定了铜绿微囊藻、斜生栅藻在不同生长期的藻细胞密度、粒径、叶绿素a浓度、浮游植物吸收系数以及比吸收系数.单因素方差分析表明,在整个培养周期中,光照强度对铜绿微囊藻及斜生栅藻的藻细胞密度、叶绿素a浓度以及440、675 nm处吸收系数均有着显著的影响.两种藻在光照强度为50μmol/(m2.s)条件下,藻细胞密度、叶绿素a浓度及吸收系数值相对最大.相关性分析表明:藻类特征波段440、675 nm吸收系数与叶绿素a浓度、藻细胞密度在不同光照条件下都存在着显著的正相关性,其中叶绿素a浓度与藻类吸收系数存在着幂函数的关系,而线性关系能更好的说明藻细胞密度与吸收系数之间的关系.在不同光照强度及培养时期,藻类比吸收系数在一定的范围内波动,随光强增加比吸收系数呈上升趋势.铜绿微囊藻440、675 nm处比吸收系数与叶绿素a浓度呈显著的负相关关系,而斜生栅藻比吸收系数与叶绿素a浓度之间无显著相关,体现了不同藻类由于色素组成及比例差异其色素包裹效应也各不相同.对不同光照强度下的铜绿微囊藻及斜生栅藻进行400～700 nm波段积分,得到了两者在5、50及100μmol/(m2.s)不同种光强下的平均比吸收系数分别为0.0144、0.0134、0.0160,0.0086、0.0088、0.0105 m2/(mg Chl.a),铜绿微囊藻比吸收系数明显大于斜生栅藻.     

水深对沉水植物苦草(Vallisneria natans)和穗花狐尾藻(Myriophyllum spicatum)生长的影响

水深是影响浅水湖泊沉水植物生长的主要因素之一.莲座型苦草（Vallisneria natans）和冠层型穗花狐尾藻（Myriophyllum spicatum）是我国长江中下游浅水湖泊中常见的沉水植物种类,二者在形态特征上具有较大的差异.在自然水体中,水深变化对这两种植物的生长以及竞争格局的影响还有待研究.本文设计了3个水深梯度（水深0.5、1.5、2.5 m）,探讨混栽条件下苦草和穗花狐尾藻生长和竞争格局对水深变化的响应.结果显示在实验系统内,中水深（1.5 m）处理组对两种植物的生长均最有利,表现为两种植物的相对生长率和生物量均最高.低水深（0.5 m）处理组苦草的生物量和相对生长率均显著低于高水深（2.5 m）处理组;穗花狐尾藻则相反,高水深对其生长的抑制作用更大.2种沉水植物在高水深胁迫时均表现出地上部分（叶长或茎长）增加,地下部分（根长）减少的形态响应特征.此外,随着水深由高到低,苦草与穗花狐尾藻生物量之比逐渐减小,表明苦草在两种植物中的竞争优势逐渐降低.研究表明湖泊水深变化不仅能够影响沉水植物的丰度,同时还可能会影响沉水植物的群落结构,而在我国浅水湖泊的生态修复实践中,在通过水位调控恢复沉水植物时,调控范围应考虑目标植物（如苦草）的光合特征.     

微囊藻毒素和温度对萼花臂尾轮虫(Brachionus calyciflorus)形态学特征的影响

近年来,随着全球变暖和水体富营养化程度的日趋严重,淡水湖泊藻类水华现象频发;由此引发的微囊藻毒素对水生生物的生态毒性效应备受关注.本实验探究了4个温度(16、20、24和28℃)和3个微囊藻毒素MC-LR浓度(2.0、4.0和6.0μg/ml)对4个品系萼花臂尾轮虫(Brachionus calyciflorus)形态特征的影响.通过2种DNA分类方法——自动条形码查询系统和Yule溯祖模型将萼花臂尾轮虫划分为3个进化种;4个品系轮虫的形态学参数总体随温度升高呈减小趋势.在16℃下,轮虫的形态特征在各品系间未见显著差异;20℃下的昆明品系KMC23形态参数最小,而西宁XN2品系最大;在24℃下,西宁XN2品系的形态参数显著增大;兰州LZB1和西宁XN2品系对温度变化的响应特征相似且在28℃下最小,这可能与两者属于同一进化种有关.4个品系轮虫的卵特征参数对温度变化的响应各有不同.可见,品系和隐种的不同是造成4个轮虫克隆形态学参数对温度差异响应的重要内源性因素.各品系轮虫中,兰州LZB1品系受温度、MC-LR及两者交互作用的影响最为显著,形态可塑性最强.在高温胁迫下,兰州LZB1品系的所有形态学参数均显著减小,但MC-LR浓度对该品系轮虫的形态学参数并未产生显著影响;经低温胁迫后,低浓度的MC-LR没有显著改变兰州LZB1品系轮虫的形态学参数,而高浓度的MC-LR显著降低了轮虫的大部分形态学参数.微囊藻毒素对轮虫形态可塑性的影响受到了内源性因素和外源性因素的综合制约.     

不同碳磷比的斜生栅藻(Scenedesmus obliquus)对同型溞(Daphnia similis)生长和繁殖的影响

食物质量会影响浮游动物的生长和繁殖,表征食物质量的指标包括食物大小、元素比、生物化学组成和毒性有无等.用斜生栅藻(Scenedesmus obliquus)的碳磷比(C/P)表征食物质量,分析不同C/P斜生栅藻对同型溞(Daphnia similis)生长和繁殖的影响.研究中4个处理组斜生栅藻C/P分别为881.8、512.3、124.3和42.4.培养9 d后不同处理组同型溞的生长速率分别为0.15、0.27、0.47和0.44 d-1.C/P比为881.8的处理组同型溞在整个培养过程中没有产仔,其余3个处理组的同型溞第1成龄期的产仔量分别为1.2±1.3、9.8±2.3和9.5±2.5 ind./female.结果表明,与斜生栅藻C/P为124.3处理条件相比,斜生栅藻C/P过高(512.3和881.8)及C/P过低(42.4)处理条件下同型溞生长速率和产仔量均降低.本研究表明食物C/P的高低会影响溞的生长和繁殖,从而影响其在湖泊中的生存.     

重污染底泥对苦草（Vallisneria natans）和黑藻（Hydrilla verticillata）繁殖体萌发及幼苗生长的影响

为探究重污染底泥对沉水植物繁殖体萌发和幼苗生长影响,以苦草（Vallisneria natans）种子和黑藻（Hydrilla verticillata）冬芽为研究对象,以轻污染底泥为对照组,通过室内模拟实验研究了重污染底泥对两种繁殖体萌发和幼苗生长、生理特性的影响。实验结果表明,与轻污染底泥相比,重污染底泥对苦草种子萌发和幼苗生长无显著影响。黑藻冬芽萌发和幼苗地上部生物量在两组间没有显著差异,但重污染底泥组幼苗的地下部生物量显著高于轻污染底泥组,其地上部和地下部生物量比值由7.06±0.38下降至2.97±0.08。此外,苦草和黑藻幼苗受到重污染底泥胁迫表现出不同的生理响应。苦草幼苗叶片的类胡萝卜素含量显著减少,可溶性糖和蛋白含量分别降低11.56%、24.10%,根系活力也明显受到抑制,仅为（34.93±3.28） mg/（g·h）;黑藻幼苗生理响应与苦草略有不同,其叶片的叶绿素a、b含量显著增加,根系活力降低44.29%,可溶性糖和蛋白含量在轻污染组和重污染组之间无显著差异。由此可见,重污染底泥对苦草种子和黑藻冬芽的萌发影响不显著,但会明显影响幼苗的生长发育和生理特性,研究结果为...     

Modified sublimation to isolate phenanthrene-degrading bacteria of the genera Sphingomonas and Burkholderia from Xiamen oil port

Sublimation was developed by Alley and Brown (2000) in order to isolate bacterial strains that were capable of degrading water insoluble compounds. In this study, sublimation was modified by the use of nutritional agar plates, instead of mineral salt agar, to isolate phenanthrene-degrading bacteria from a mixed culture that had been enriched under the selective pressure of high phenanthrene content. Five strains were obtained with different morphology and degradation ability. Based on the 16S rDNA sequence, two of them were classified as species of the genus Sphingomonas; the others as species of the genus Burkholderia. Denaturing gradient gel electrophoresis (DGGE) was introduced to detect dynamic changes in the bacterial community during enrichment batch culture, and to determine any correlation between the five isolates and the phenanthrene-degrading consortium. The DGGE profile indicated that these five isolates corresponded to four dominant bands of the consortium. Compared to traditional means of isolation, we concluded that modified sublimation is effective and more convenient.     

基于离散三维活体荧光光谱法的湖泊水体叶绿素a浓度原位测量

荧光光谱分析技术具有灵敏度高、检测快速等优点,三维荧光光谱提供的指纹荧光信息比普通荧光光谱更丰富,选择性更好,在多组分分离上更具优势.离散三维活体荧光光谱法通过提取水体蓝藻、绿藻、硅藻、甲藻和隐藻5个门类藻类荧光光谱的指纹特征,分类测量藻类叶绿素a浓度,经过加和得到总的水体叶绿素a浓度.将基于该方法研制的三维荧光光谱水体藻类原位测量仪用于太湖水体叶绿素a浓度的测定,并与YSI多参数水质检测仪、BBE藻类现场分析仪、分光光度法等测定结果对比,结果表明:该方法与分光光度法间无显著性差异,与分光光度法、BBE法间的相关性好,相关系数达0.96以上,精密度、准确率优于基于普通荧光法的原位测量仪,是一种快速有效的原位测量方法.     

微囊藻(FACHB-905)和鱼腥藻(FACHB-82)响应温度变化的功能特性权衡

微囊藻和鱼腥藻是水华蓝藻的两个主要类群,两种藻均可调节自身形态及生理特性来维持快速生长,这也是两个类群蓝藻水华维持的基础.本研究分析了微囊藻(FACHB-905)和鱼腥藻(FACHB-82)生长、形态及叶绿素荧光参数对温度变化的响应,以及生长与特性间的权衡关系.结果显示:该微囊藻细胞直径随温度升高而降低,但是比增长速率维持稳定,表明在高温条件下,其可能通过减小细胞大小的方式维持比增长速率;该鱼腥藻在不同温度下,平均细胞直径和藻丝长度呈现显著变化,高温条件下,其维持较高的比增长速率,但是细胞直径增大,藻丝长度缩短,这可能是其调节自身形态以维持较高比增长速率的方式.该微囊藻和鱼腥藻分别在细胞较大和较小时,藻细胞潜在的光化学效率更高.本研究表明这两种蓝藻可以通过权衡藻细胞形态、生理特性两者与生长速率之间的关系来适应温度的变化以达到自身最佳的生长状态,微囊藻(FACHB-905)通过调节细胞大小和光合活性来维持生长优势,而鱼腥藻(FACHB-82)则通过细胞大小、藻丝长度和光合活性的调节来维持生长优势.本研究的结果有助于提升对于水华蓝藻生长维持机制的认识.     

甲醛溶液对发头裸腹溞及其体表聚缩虫影响的试验

不同浓度的甲醛溶液对枝角类发头裸腹溲Ｍｏｄｉｎａｉｒｒａｓａ的致毒效应以及对其体表附着的聚缩虫Ｚｏｏｔｈａｍｉｕｍｓｐ．的杀灭效果的试验结果表明,１２ｈ、２４ｈ两俱和用时段中,甲醛浓度与发头裸腹溲相对存活率之间以及甲醛浓度与发头裸腹溲体表聚缩虫营养体脱落率之间存在一定的函数关系。