Comparative Analysis of Foraging Behavior in Aquatic and Semiaquatic Spiders of the Genera Argyroneta,Dolomedes, Pirata,and Pardosa

A group of sympatric aquatic and semiaquatic spiders inhabiting Western Siberia (Argyroneta, Dolomedes, Pirata, and Pardosa) has been studied with respect to specific ethological features. The results provide a basis for the conclusion that these spiders differ in a number of behavioral adaptations related to prey catching and the use of common biotopic space. Experiments with the predator–prey system have shown that spiders have different effects on the abundance of bloodsucking mosquito larvae and on the age and genetic structure (at the chromosomal level) of their populations. The functional role of spiders in communities is discussed.     

The Impact of Pollution on the Meroplankton of Gaidamak Bight (Vostok Bay,Sea of Japan)

The taxonomic composition, concentration, and distribution of meroplankton have been studied in Gaidamak Bight, Peter the Great Bay, chronically exposed to anthropogenic impact. It has been demonstrated that, in addition to larvae of benthic invertebrates resistant to pollution, the larvae of other species are always abundant in the bight. They drift with currents from neighboring clean water areas, thus maintaining the high reproductive potential of meroplankton in the bight. Therefore, if this water area was cleared of pollutants, it could be populated again by species that have disappeared from it.     

双酚AF暴露对胚胎期和幼鱼期斑马鱼的毒性效应

为明确不同发育阶段的斑马鱼对BPAF(双酚AF)暴露的易感性,采用暴露试验法初步研究了BPAF对胚胎期和幼鱼期斑马鱼的发育毒性. 结果表明:①BPAF暴露可延缓胚胎期斑马鱼的发育和孵化,使其出现心包水肿、卵黄囊异常、心率下降、心脏搏动停止等症状. ②暴露96 h后,ρ(BPAF)为2.0、2.5、3.0 mg/L暴露组胚胎期斑马鱼的畸形率高达100%,暴露24 h致畸的EC₅₀(半数效应浓度)为2.00 mg/L,暴露96 h的LC₅₀(半数致死浓度)为1.84 mg/L. ③暴露72 h后,对照组幼鱼期斑马鱼鱼鳔发育缺陷率为0;除ρ(BPAF)为1.0 mg/L暴露组外,其余BPAF暴露组幼鱼期斑马鱼鱼鳔发育缺陷率为100%. ④随着暴露时间的延长以及中毒程度的加深,幼鱼期斑马鱼出现的中毒症状依次表现为心包水肿、卵黄囊水肿、背脊弯曲、心跳停止,暴露48和72 h时其心包水肿的EC₅₀分别为1.76、1.56 mg/L,暴露96 h的LC₅₀为1.77 mg/L. 胚胎期和幼鱼期斑马鱼对BPAF暴露响应的差异分析显示,幼鱼期斑马鱼对BPAF暴露的反应更为敏感,幼鱼期斑马鱼的心包水肿症状可作为BPAF毒性响应的最佳指标之一.      

Acute toxicity of ammonia to a freshwater teleost,Labeo bata larvae

Ammonia toxicity tests were performed with Labeo bata (bata) larvae of three different size groups. One hundred percent survival of larvae (500.0?±?4.0?mg) was recorded when exposed to ammonia concentrations of 1.0–13.56?mg?L^?1 at 96?h of exposure. Bata larvae exposed to ammonia concentrations of 15.8–25?mg?L^?1 showed 10–74% mortalities. The 96?h LC₅₀ value for 200 (±5), 250 (±2) and 500 (±4) mg bata larvae were 11.5, 16.8 and 22.5?mg?L^?1 un-ionised ammonia concentrations, respectively. When fish were exposed to different doses of ammonia, behavioural changes immediately occurred even at the lowest dose. At first, the fish became hyperexcitable, the skin darkened and they showed an increased ventilation frequency, fish behaviour became normal, 24?h after exposure. A 96?h LC₅₀ value of un-ionised ammonia showed direct relationship with the increasing size of bata larvae.     

In vitro and in vivo inhibition of Ca2+-Mg2+-ATPase activity by cadmium in post larvae of Penaeus monodon

Ca²⁺-Mg²⁺-ATPase is a membrane-bound enzyme and is responsible for regulating cytosolic free calcium. In vitro and in vivo effects of cadmium were studied on Ca²⁺-Mg²⁺-ATPase activity in plasma membrane/mitochondrial fraction of Penaeus monodon post larvae. In vitro studies revealed a concentration-dependent decrease in enzyme activity with an IC₅₀ value of 11.02?µM. In vivo experiments were conducted by exposing the post larvae to 1/10th (0.12?ppm) and 1/5th (0.24?ppm) of LC₅₀ values of cadmium for 30 days. Both ATPase activity and metal accumulation were estimated in post larvae exposed to 0.12 and 0.24?ppm of cadmium at different intervals of 24?h, 48?h, 96?h, 10 days and 30 days. ATPase activity showed a gradual decrease in post larvae on exposure to both the sub-lethal concentrations with respect to their controls and the decrease was significant (p?相似文献   

芘污染对马氏珠母贝(Pinctada martensi)D型面盘幼虫发育的影响

多环芳烃(PAHs)是一类广泛存在于环境中的持久性有机污染物,大多具有潜在毒性、致癌性及致畸诱变作用。选取马氏珠母贝(Pinctada martensi)作为模式动物,研究芘对马氏珠母贝D型面盘幼虫发育的影响。将马氏珠母贝D型面盘幼虫暴露于不同浓度(2、4、8、16和32μg·L-1)芘(pyrene)中,在暴露后第12、24、36、48、60、72和84小时,分别测定其死亡率和畸形率,并观察形态学的变化。结果表明,芘对D型面盘幼虫的发育有显著影响,同一浓度组的死亡率与时间呈正相关。在2～32μg·L-1浓度范围内,不同暴露时间段,死亡率与浓度呈正相关。芘暴露对马氏珠母贝D型面盘幼虫的形态也有显著影响,随着芘浓度的增大幼虫畸形的比例增高,并呈现明显的剂量-效应关系,其中8和32μg·L-1浓度组的响应最敏感。同时,芘暴露对马氏珠母贝D型面盘幼虫的半数致死浓度(LC50)随着时间的推移逐渐降低,60h后趋于稳定,LC50值为43.50μg·L-1。研究结果表明,芘暴露能影响马氏珠母贝D型面盘幼虫的发育,并可能对其种群结构产生不利影响。     

微小亚历山大藻对黑鲷早期生长发育的毒性效应

通过微小亚历山大藻（Alexandrium minutum）对黑鲷（Sparus macrocephalus）胚胎及仔鱼的急性和亚急性毒性的实验,研究了微小亚历山大藻其藻细胞液和细胞破碎液对黑鲷幼体的生物毒性效应.结果表明,微小亚历山大藻对黑鲷胚胎的孵化产生不利影响,影响程度随藻细胞浓度的增加而增加.在仔鱼96h的急性毒性实验中,微小亚历山大藻对仔鱼的96h理论半致死浓度分别为1.0×105 cell·mL-1 (藻细胞破碎液)、8.0×104 cell·mL-1 (藻细胞液),而在7d的亚急性实验中,高浓度藻细胞液对仔鱼的生长发育有一定的抑制作用,且相同浓度下,藻细胞液产生的毒性较藻细胞破碎液大.     

Common volatiles are major attractants for neonate larvae of the specialist flea beetle <Emphasis Type="Italic">Altica koreana</Emphasis> (Coleoptera: Chrysomelidae)

Olfactory stimuli play an important role in the host searching of larval phytophagous insects. Previous studies indicate that larvae that have to find feeding sites after hatching are generally attracted to host volatiles. However, there are few studies on the olfactory responses of neonate larvae to host volatiles in cases when those larvae hatched on the host plant. In the present study, we determined the olfactory responses of neonate larvae of the specialist flea beetle, Altica koreana Ogloblin, to host and six non-host plants, using a static-air "arena." Larvae responded significantly to the host plant Potentilla chinensis Ser. and five of six non-host plants, compared to the control. Larvae did not prefer the host plant over the non-host plants (except Artemisia sp.) when offered a choice. Additionally, odours of a non-host plant, which were unattractive to neonate larvae, may have masked the attractive odour of the host plant. These results indicate that common volatiles can play a major role in attracting larvae of this specialist to plants, but attraction to such odours may not be the major mechanism of host choice.     

CO2 leakage simulation: effects of the pH decrease on fertilisation and larval development of Paracentrotus lividus and sediment metals toxicity

Carbon capture and storage has become a new mitigation option to reduce anthropogenic CO₂ emissions. The effects of the CO₂-related acidification, associated with unpredictable leaks of CO₂ during the operational phases were studied using the Paracentrotus lividus sea urchin-liquid-phase-assays (fertilisation and embryo-larval development tests). Besides to the direct effects of the CO₂-associated pH decrease, the possible effects on marine sediment toxicity were studied by exposing the urchin larvae to elutriate of sediments with different metals concentration, which were subjected to various pH treatments. The resulted median toxic effect pH ranged from 6.33?±?0.02 and 6.91?±?0.01 for the egg fertilisation, and between 6.66?±?0.03 and 7.16?±?0.01 for the larval development assays. Concentrations of Co, Zn, As, Cu, and Fe were detected in the sediment elutriates. For all the sediment elutriates tested the amount of the dissolved Zn increased in parallel with the pH reductions. Correlated effects of acidification, biological response, and the presence of dissolved metals were observed in this work evidencing that the most important factor controlling the reduction of egg fertilisation and larval development success was the combined effects of the reduction of pH and the presence of the contaminants (mainly Zn, Co, and As).     

三丁基锡对摇蚊幼虫的毒性作用

研究氯化三丁基锡对摇蚊幼虫的毒性作用,结果表明,ＴＢＴ对红德永摇蚊幼虫４８ｈＬＣ５０为２８５．４μｇ／Ｌ,ＴＢＴ对羽摇蚊幼虫２４ｈＬＣ５０为１６．６μｇ／Ｌ;１０ｄ中,ＴＢＴ浓度为２５μｇ／Ｌ时红德永摇纹幼虫的下唇板出现可观察到的畸变;