实验围栏内越冬眠镜蛇体温调节和低温耐受性的无线电遥测

用SB－2T内置热敏无线电发射器、HOBO和TINYTALK数据记录块等电子设备研究实验室围栏内越冬眼镜蛇（Naja atra)的体温调节和低温耐受性。围栏内总平均气温（10．6℃）与总平均巢温（10.9℃）无显著差异,但气温变化幅度（－2.0-37.4℃）大于巢温变化幅度（6．5－14．5℃）。眼镜蛇体温变化幅度（3．4－34．1℃）介于气温和巢温的变化幅度之间,平均体温的个体间差异显著,总平均体温（15．0℃）大于平均气温和平均巢温。最低体温的平均值为8．9℃,与经验估测的眼镜蛇低温耐受极限（9．0℃）相近。白天气温高于15℃时能见到巢外调温个体,其体温记录次数的占处于此条件下的个体总体温记录次数的29％。巢外调温个体的体温高于处于晚间和白天15℃以下气温个体的体温,亦高于处于白天15℃以上气温但不进行巢外调温个体的体温。处于白天15℃以下气温个体的体温低于晚间个体的体温。处于白天15℃以上气温但不进行巢外调温个体的体温与处于晚间和白天15℃以下气温个体的体温无显著差异。处于晚间和白天15℃以下气温个体的体温与气温呈显著的正相关,眼镜蛇在体温和缺乏热斑块的环境中是体温调节的顺应者。气温高于15℃时,进行巢外调温和不进行巢外调温个体的体温均与气体无关,无明眼镜蛇在气温相对较高且具有热斑块的环境中是体温调节的调节者。将眼镜蛇持续暴露在9℃以下能导致其死亡,但短期将眼镜蛇暴露在耐受体温以下的热环境中对其无直接的致死影响。     

实验围栏内越冬眼镜蛇体温调节和低温耐受性的无线电遥测

用SB 2T内置热敏无线电发射器、HOBO和TINYTALK数据记录块等电子设备研究实验室围栏内越冬眼镜蛇 (Najaatra)的体温调节和低温耐受性。围栏内总平均气温 (10 6℃ )与总平均巢温 (10 9℃ )无显著差异 ,但气温变化幅度 (- 2 0～ 37 4℃ )大于巢温变化幅度 (6 5～ 14 5℃ )。眼镜蛇体温变化幅度 (3 4～34 1℃ )介于气温和巢温的变化幅度之间 ,平均体温的个体间差异显著 ,总平均体温 (15 0℃ )大于平均气温和平均巢温。最低体温的平均值为 8 9℃ ,与经验估测的眼镜蛇低温耐受极限 (9 0℃ )相近。白天气温高于15℃时能见到巢外调温个体 ,其体温记录次数约占处于此条件下的个体总体温记录次数的 2 9%。巢外调温个体的体温高于处于晚间和白天 15℃以下气温个体的体温 ,亦高于处于白天 15℃以上气温但不进行巢外调温个体的体温。处于白天 15℃以下气温个体的体温低于晚间个体的体温。处于白天 15℃以上气温但不进行巢外调温个体的体温与处于晚间和白天 15℃以下气温个体的体温无显著差异。处于晚间和白天 15℃以下气温个体的体温与气温呈显著的正相关 ,表明眼镜蛇在低温和缺乏热斑块的环境中是体温调节的顺应者。气温高于 15℃时 ,进行巢外调温和不进行巢外调温个体的体温均与气温无关 ,表明眼镜蛇在气温     

尖吻蝮和舟山眼镜蛇初生幼体的捕食性攻击行为

毒蛇捕食行为通常可以分为3个阶段:攻击前、攻击和攻击后阶段,其中攻击阶段在整个行为过程中起着决定性的作用。用数码摄像机拍摄了4个体温下尖吻蝮和舟山眼镜蛇幼体捕食小白鼠的行为过程,通过分析10个行为变量来比较两者捕食性攻击模式的差异并检测温度对攻击行为的影响。两种蛇对猎物产生明显不同的攻击反应。攻击前,尖吻蝮感应猎物能力相对较弱,头部移动速度缓慢,准备时间较长;攻击时,尖吻蝮头部移动速度显著大于舟山眼镜蛇;攻击注毒后两种蛇均释放猎物,尖吻蝮头部回缩至攻击前状态的时间间隔相对较短。体温显著影响两种蛇的攻击行为。在检测的温度范围内,两种蛇都在28℃体温条件下感应猎物能力达到最好;温度效应对尖吻蝮攻击速度的影响显著,但对舟山眼镜蛇不显著。不同蛇类捕食行为模式以及对体温变化反应的差别可能主要与其利用感觉器官、生境条件上的种间差异有关。     

眼镜蛇入蛰前和出蛰后血液粘性的变化

利用血液流变学的理论和技术对入蛰前和出蛰后的眼镜蛇血液进行粘滞性、浓稠性及血细胞聚集性的比较分析,发现:(一)眼镜蛇的血液处于低粘滞性、低浓稠性及血细胞低聚集性的状态。(二)眼镜蛇出蛰后血液粘性比入蛰前非常显著增高,血液流速减慢,致使组织器官血液供应不足,影响了眼镜蛇出蛰后的活动,故其活动能力比入蛰前差。     

三个种群有尾和断尾丽斑麻蜥的选择体温、表面活动和摄食量

用2006年4-6月捕自长安(陕西)、共和(青海)、哈尔滨(黑龙江)三个地理隔离种群尾部完整的丽斑麻蜥(Eremias argus)成年雄体检测断尾对选择体温、表面活动(表面调温个体数)和摄食量的影响。各种群个体均分为实验和对照组,在距尾基部10 mm处切除实验组蜥蜴尾部,获得断尾个体。实验和对照组个体饲养在相同的实验室条件下收集相关数据,历时四周。表面活动的种群间差异是不同种群个体对其所处区域热环境长期适应的结果。断尾个体减少表面活动见于所有三个种群,表明尾自切能导致丽斑麻蜥活动水平的改变。同一种群断尾和有尾个体表面活动的时间格局无显著差异,不同种群表面活动的时间格局无显著差异,这些结果表明丽斑麻蜥白天活动节律具有种的特异性,不受断尾影响。丽斑麻蜥选择体温随纬度或海拔升高而降低,这种变化趋势可能是热环境制约的结果。所有三个种群断尾个体的选择体温均低于有尾个体,表明断尾可改变丽斑麻蜥的体温调定点。丽斑麻蜥摄食量存在种群间差异,长安种群蜥蜴的摄食量显著大于共和种群蜥蜴。三个种群断尾个体均未增加摄食以满足尾再生的额外能量需求,表明增加摄食不是该种蜥蜴补偿断尾能量代价的对     

北草蜥种群间生活史变异的成因分析:热环境、食物可利用性和体温的岛屿间差异

比较浙江温州北麂岛与洞头岛的热环境、食物可利用性以及动物体温,以辨析北草蜥岛屿种群间生活史特征差异中环境因子的作用。通过测定岛屿上北草蜥栖息地植被和环境温度,比较岛屿热环境的差异。野外测定活动蜥蜴的体温、环境温度和活动规律,实验室温梯板中测定动物喜好体温。用陷阱法测定无脊椎动物多样性和丰度,以比较岛屿蜥蜴种群的食物可利用性。岛屿植被存在差异导致热环境的差异。洞头岛植被高于北麂岛,地表层光线透入率则低于北麂岛。因而,洞头岛郁闭地表的平均温度和最高温度显著低于北麂岛,但两岛裸露地面的温度无显著差异。热环境的岛屿间差异进而影响北草蜥的野外体温。在春季,洞头岛的野外有效温度和基底温度显著大于北麂岛,而两岛北草蜥的体温无显著差异;在夏季,洞头岛的北草蜥体温、有效温度和基质温度均显著高于北麂岛;到秋季,北麂岛蜥蜴体温和环境温度高于洞头岛。地面无脊椎动物多样性和丰度的岛屿间差异表明北麂岛食物可利用性大于洞头岛。岛屿间北草蜥日活动规律和喜好体温无显著差异。本研究表明:(1)温度和食物可利用性存在岛屿间差异,岛屿种群间生活史特征差异可能与之有关;(2)两岛屿北草蜥主要采取行为调节对策来适应自然界的热环境变化,尚未发现热生理学特征的进化性漂移[动物学报51(5):797-805,2005]。     

华北丽斑麻蜥食物同化和疾跑速的热依赖性

作者研究山西阳泉丽斑麻蜥(Eremias argus)成体的选择体温、热耐受性及食物同化和疾跑速的热依赖性。选择体温、临界低温和临界高温无显著的两性差异,分别为36·0℃、1·0℃和44·9℃。在实验温度范围内,体温显著影响食物通过时间、日摄食量、日粪尿排量、表观消化系数和同化效率。食物通过时间在26 -34℃范围内随体温升高而缩短,在更高的体温下则延长。蜥蜴在30、32、34和36℃体温下明显摄入较多的食物、排出明显较多的粪尿。34℃和36℃下的表观消化系数和同化效率大于其它更低或更高温度下的对应数值,但这两个变量未因体温变化而呈现清晰的规律性变化。疾跑速在18 -36℃范围内随体温升高而加快,在38℃体温下则减缓。36℃或附近体温最适合疾跑速。疾跑速最适体温接近蜥蜴的选择体温,表明蜥蜴疾跑速的最适温度可能与其选择体温密切相关[动物学报52 (2) : 256 -262 , 2006]。     

中华眼镜蛇伤大鼠模型多项电生理指标的动态观察

目的建立中华眼镜蛇毒挑战剂量的大鼠模型,通过对多项电生理指标的动态观察,为蛇毒毒理及抗蛇毒制剂的研究提供实验数据。方法将SD大鼠分为蛇毒组、血清保护组和对照组,戊巴比妥腹麻,连续记录心率、血压、呼吸频率及心电图等电生理指标的动态变化,观察眼镜蛇毒的毒性反应及抗蛇毒血清对动物的保护作用。结果腹腔注入挑战剂量(4×LD50:4×0.636 mg/kg)的中华眼镜蛇毒后,大鼠平均生存时间为(3±0.33)h。蛇毒组给药30~60 min后,心率及呼吸频率均有轻度加快,Ⅱ导联ST段抬升幅度超过同期正常对照0.1 mV以上(P<0.05);130~150 min后,心率、呼吸频率及动脉血压均直线下降;达180 min时,心率、呼吸频率及动脉血压均已降到同期正常对照的30%以下,差异非常显著(P<0.01)。血清保护组给药后各指标相对平稳,与对照组比较无明显差异。结论以4倍LD50为挑战剂量造模的中华眼镜蛇伤大鼠模型,心率、血压、呼吸频率及心电图等电生理指标的动态变化与临床症状基本相符。眼镜蛇毒抗血清可有效地中和、保护眼镜蛇毒对机体的伤害。     

肇庆南草蜥形态、食性及运动表现的两性差异

通过测量头、尾、体和胃检,研究肇庆南草蜥Takydromus sexlineatus个体发育过程中两性异形和食性差异。南草蜥成体个体两性大小无显著差异,雄性头部显著大于雌性,两性头部大小异形可能是受到性选择压力的结果。雌雄个体食物生态位重叠度较高,两性生态位差异微弱,食性差异与两性头部异形无明显相关性。通过设计13种不同的环境温度,研究体温变化对南草蜥两性个体运动能力表现的影响。结果显示环境温度通过影响体温而影响南草蜥的运动表现,两性个体疾跑速均具有在低体温范围内随体温升高而加快、在高体温范围内随体温升高而降低的模式。在多数测试温度下,雄体的疾跑速均略大于雌体,但两者平均值在统计上无显著差异。体温对南草蜥的最大持续运动距离和停顿次数的影响显著,两性个体的疾跑速和最大持续运动距离呈显著正相关。雄性和雌性分别在26℃和30℃具有最佳的运动表现。     

On the role of the pineal in thermoregulation in the pigeon

Diurnal rhythm in body temperature of pigeons subjected to different experimental conditions (pinealectomized, sham-operated, melatonin-implanted, cold-exposed) was studied under a 12 h light and 12 h dark regimen. The body temperature of pigeons during photophase was higher than that during scotophase in the normal as well as every treatment group studied. Pinealectomized pigeons showed higher body temperature in the photophase as well as scotophase, than that of the normal and sham-operated birds when examined 2 or 3 weeks following the post-surgical acclimatization to 25 or 3 degrees C. However, subcutaneous implantation of melatonin pellets into pinealectomized pigeons nullified or even reversed the hyperthermic effect of pinealectomy. Exposure of pigeons to--18 degrees C for 280 min during photophase as well as scotophase, produced a marked drop in body temperature in pinealectomized, sham-operated and normal pigeons. The pinealectomized pigeons exhibited a higher body temperature than that of the sham-operated and normal ones when exposed to--18 degrees C during the photophase, but not during the scotophase. It was concluded that while the pineal is not necessary for maintaining the daily thermal rhythm in the avian body, it has a thermoregulatory role, in that it prevents rise in body temperature in warm (25 degrees C) acclimatized and chronic cold (3 degrees C) exposed birds. In acute short-term cold (--18 degrees C) exposure however, the temperature regulatory role of the pineal was not effective during the scotophase.     

The effect of feeding regime on growth, locomotor activity pattern and the development of food anticipatory activity in greenback flounder

The mean final weight of juvenile greenback flounder Rhombosolea tapirina fed a single daily meal during the scotophase was lower than that of groups fed continuously or fed twelve, six, three or one meal during the photophase. Final weight did not differ among the latter five groups. Size variation in all groups of fish decreased during the course of the trial over 120 days. Groups assigned to a higher frequency (and hence a longer total daily meal duration) of daily meals were less active during mealtime. A distinct food anticipatory effect was observed in the groups of fish receiving a single daily meal during either photophase or scotophase, and also developed before at least one meal in the group of fish fed three meals per day.     

Diel variations in plasma glucose concentrations of Malachite Sunbirds Nectarinia famosa

Plasma glucose concentrations in birds are much higher than those in mammals of similar body mass, and they are thought to be kept more or less constant. We investigated plasma glucose concentrations of Malachite Sunbirds (Nectarinia famosa) to determine whether there was a circadian rhythm in plasma glucose and whether plasma glucose concentrations rose at lower temperatures. We explored the possibility that glycogenolysis and gluconeogenesis might be used by birds before daylight to generate body heat during arousal from torpor or from overnight adaptive heterothermy. Plasma glucose concentration of Malachite Sunbirds were relatively high, between 13.6 and 21.4 mmol/L. Plasma glucose concentrations were higher at 5°C than at 25°C, and generally lower during the scotophase, particularly in the early hours of the morning. Therefore, it appears that Malachite Sunbirds are not increasing plasma glucose concentrations during arousal from torpor or to increase scotophase body temperature levels to photophase levels. It is apparent that these nectarivorous birds have a circadian variation in plasma glucose concentrations that is affected by ambient temperature and feeding patterns.     

Thermal orientation of Anthonomus pomorum (Coleoptera: Curculionidae) in early spring

Abstract. The selection of habitats with favourable temperature by the apple blossom weevil Anthonomus pomorum (L.) is investigated in a temperature gradient arena with a range of approximately 0–15 °C. Single female and male weevils are tested in the arena 2, 4 and 6 days after termination of diapause, during photophase and during scotophase. During photophase, weevils of both sexes choose the warmest part of the temperature gradient arena, irrespective of the time elapsed after diapause. During scotophase, high temperature is favoured by male weevils, as well as by females 2 and 4 days after diapause. However, 6 days after termination of diapause, females show no thermal preference in the temperature gradient arena during scotophase, indicating that thermal choice of female A. pomorum in the scotophase changes with time after the termination of diapause. The results suggest that both sexes benefit from thermoregulation by habitat choice during photophase when the weevils are flight active and colonize apple trees.     

Nocturnal parasitism of moth eggs by Trichogramma wasps

Parasitoid wasps of the genus Trichogramma are used worldwide as biological control agents against lepidopteran pests. Trichogramma wasps develop inside eggs of a wide range of host species, most of them moths. They are generally considered as diurnal insects. Here, we investigated whether Trichogramma wasps can also successfully parasitise host eggs at night under controlled laboratory conditions. Eggs of the moth Ephestia kuehniella were offered under dark conditions (scotophase) to females of Trichogramma brassicae and Trichogramma evanescens either from 9:00 PM to 9:00 AM or from 11:00 AM to 5:00 PM at four different temperatures (5°C, 10°C, 15°C and 20°C). Both species are known to parasitise E. kuehniella eggs in the photophase during daytime. The results show that T. brassicae did not parasitise eggs in the scotophase at night and only very few in the artificially induced scotophase during daytime from 10°C to 20°C. In contrast, T. evanescens parasitised more eggs in the dark both at night and artificially induced scotophase during daytime. Parasitism in the scotophase already started at 5°C, with more eggs being parasitised and more offspring being produced at higher temperatures. T. evanescens displayed higher parasitism activity in the induced scotophase during daytime than in the scotophase at night. The present study suggests that Trichogramma are capable of successfully parasitising host eggs at night, even at low temperatures, but that nocturnal activity with respect to parasitism varies between wasp species.     

Diurnal locomotion and feeding activities of two rice-ear bugs,Trigonotylus caelestialium and Stenotus rubrovittatus (Hemiptera: Heteroptera: Miridae)

Diurnal locomotion and feeding activities of Trigonotylus caelestialium (Kirkaldy) and Stenotus rubrovittatus (Matsumura) were investigated using a video camera and electrical penetration graph. Diurnal locomotion activity of T. caelestialium was higher in photophase than in scotophase, whereas that of S. rubrovittatus was higher in scotophase than in photophase. No difference was observed in the locomotion activity of T. caelestialium between mated and unmated bugs or between males and females. Locomotion activity of S. rubrovittatus was different between the sexes. The activity of females was higher than that of males. Diurnal rhythms of feeding activity were obscure compared with those of the locomotion activities in both mirids. The feeding behavior of T. caelestialium was significantly more active in the photophase than in the scotophase. In S. rubrovittatus, feeding activity of males was higher in the scotophase than in the photophase, whereas females showed no such difference. It is thought that both species of mirid bugs are active during the daytime and nighttime, although the locomotion and feeding activities of T. caelestialium were high in the photophase, while those of S. rubrovittatus were high in the scotophase.     

Environmental regulation of female calling and male pheromone response periodicities in the codling moth (Laspeyresia pomonella)

Codling moth female calling and male pheromone responsiveness under the defined conditions of 23°C and light:dark (LD) 16:8 occurred primarily during scotophase. Under either continuous photophase or scotophase females called with periodicities very similar to their periodicity under the LD cycle, indicating that the rhythmicity is circadian. Male response rhythmicity was maintained under continuous photophase. A decrease in the temperature from 23° to 16°C resulted in a reduction in the proportion calling when the decrease in temperature occurred during scotophase and a shift of maximal calling into photophase when the decrease in temperature occurred 3 hr prior to the initiation of scotophase. Decreases of temperature from 23° to 16°C and of light intensity did not produce similar shifts in the periodicity of male upwind orientation. Of 6 pheromone dosages from 10^?5 to 10² μg, 10^?1 and 10⁰ μg elicited the most male upwind orientation.     

The role of the main photophase on dark-time measurement used for diapause determination in the Indian meal moth, Plodia interpunctella

Abstract.  The Indian meal moth Plodia interpunctella Hubner (Lepidoptera: Pyralidae) measures night length and enters diapause as a last-instar larva. To examine the role of photophase on dark-time measurement, the main LD 7 : 17 h photoperiod is disrupted by various lengths of darkness at 25 °C. When the light phase is not disrupted, the incidence of diapause is 76%. As the dark pulse disrupting a 7-h photophase becomes longer, the incidence of diapause decreases. To detect the dynamic kinetics of the time-measuring process, the main scotophase of 17 h is scanned by a 2-h light pulse. When the dark pulse in a 7-h photophase is fixed at 1 h after dawn and its duration is varied systematically from 1 to 3 h, or when the end of the dark pulse is fixed at 1 h before dusk, diapause is prevented completely by a 2-h light pulse inserted in the middle of 17-h darkness. These results are compared with those of a single night interruption of a 17-h scotophase with a 2-h light pulse but with an intact 7-h photophase. The disruption of a 7-h photophase by a dark pulse shifts the descending and ascending slopes of the response curve to some extent toward dawn and dusk, respectively, indicating that the dark pulse tends to shorten the critical length of dark time for diapause induction. When the main photophase (7 h) is interrupted by a 1-h dark pulse at 3–4 h after dawn, the 2-h scanning light pulse in the main scotophase (17 h) appears to act effectively as a dusk signal in the early scotophase. However, those in the mid- and late scotophase do not define the critical night length from dusk as sharply as for the critical night length from a 2-h light pulse to dawn. The results indicate the importance of photophase in the dark-time measurement.     

Melatonin and locomotor activity in the fiddler crab Uca pugilator

The influence of melatonin on locomotor activity levels was measured in the fiddler crab Uca pugilator. First, activity in untreated, laboratory-acclimated crabs was measured over 48 hours in a 12L:12D photoperiod; this study showed a nocturnal increase in activity. In eyestalk-ablated crabs, overall activity was significantly reduced, and no significant activity pattern occurred. Next, crabs were injected with melatonin or saline (controls) at various times during the 12L:12D photoperiod (0900h, 1200h, and twice at 2100h; each trial was separated by 3-4 days) and monitored for 3 hr post-injection. Control crabs had low activity during early photophase, high at mid-photophase, increasing activity during the first scotophase trial, and decreasing activity during the second scotophase trial. Melatonin had no significant influence on activity when injected during the early-photophase activity trough or early-scotophase activity decline, but significantly increased activity when injected during the mid-photophase activity peak and early-scotophase activity incline. Next, crabs were injected during an early scotophase activity trough and monitored throughout the twelve-hour scotophase. Melatonin did not increase activity until the mid-scotophase activity increase, approximately 6 hours later, showing that the pharmacological dosage persisted in the crabs' systems and had later effects during the incline and peak of activity but not the trough. Eyestalk-ablated crabs were injected with melatonin or saline during early photo- and scotophase. Melatonin significantly increased activity in the photophase but not the scotophase trial, indicating that the responsiveness to melatonin continues following eyestalk removal, but the timing may not match that of intact crabs. Melatonin may be involved in the transmission of environmental timing information from the eyestalks to locomotor centers in U. pugilator.     

Diel rhythms of adipokinetic hormone, fat body response, and haemolymph lipid and sugar levels in the house cricket

Abstract. The adipokinetic hormone (Grb-AKH) content in the corpora car-diaca of the house cricket, Acheta domesticus , varied during a day with two peaks in the scotophase and one peak in the photophase. There were two distinct peaks of total lipid concentration in the blood, one early in the photophase and the other early in the scotophase. Fat body sensitivity to adipokinetic hormone also varied in close synchrony with the lipid rhythm. It was not possible to attribute the rhythm of blood lipid titre unequivocally to either the rhythm of adipokinetic hormone content in the corpora cardiaca or to the rhythm of sensitivity of the fat body to the hormone. In adult crickets the blood carbohydrate titre had two peaks in adult females, one towards the end of scotophase and another in the late photophase (c. 12h apart), but a single peak at the end of scotophase was apparent in last instar larvae. The blood carbohydrate rhythm persists in DD and is therefore endogenous. Carbohydrates were not mobilized by the Grb-AKH, therefore could not be involved in the blood carbohydrate rhythm. Exposure to various day lengths caused shifts in the patterns of the carbohydrate rhythms, but imposition of a cyclic temperature regime had no effect on the rhythm.