桡足类滞育规律研究

首次提出用滞育指数对桡足类滞育能力进行相对量化处理 ,并对 10 2种桡足类的滞育能力同迁移能力、体长、栖息地之间的关系进行了数学分析 ,初步得出了滞育在桡足类中的分布规律 :在桡足类中滞育与迁移呈负相关 ,两者之间存在一定程度的置换 ;个体较小的桡足类一般具有较强的滞育能力和较弱的迁移能力 ,个体较大的桡足类一般具有较弱的滞育能力和较强的迁移能力 ;淡水桡足类一般比海洋桡足类具有较强的滞育能力。最后探讨了这种分布模式的成因     

植食性浮游桡足类摄食生态学研究进展

由于浮游动物在调节海洋生物生产中的关键作用,对其摄食生态学的研究一直是海洋生态学研究的重点。总结了近年关于浮游动物主要类群－桡足类对浮游植物摄食的研究进展及其在海洋生态系统动力学研究中的重要意义。主要包括：影响植食怀桡足类摄食强度的主要因素,饵料对于桡足类种群变动的影响;现场测定桡足类摄食率的方法以及海洋生态系统动力学研究中需要关注的问题。     

拓林湾浮游桡足类生态研究

2000年7月至2001年7月的周年调查结果表明,粤东柘林湾浮游桡足类29属57种,其中,强额拟哲水蚤Paracalanus crassirostris和短角长腹剑水蚤Oithona brevicornis为优势种,合计占浮游桡足类总个体数的66.7%.柘林湾是一个浮游桡足类相对丰富的海湾,年均总个体数达5.4×10³ind.·m^-3.浮游桡足类的种类数和总个体数均表现为湾外大于湾内的平面分布格局,周年变化基本上为单峰型,高峰期位于5~10月,最低谷位于冬季1月。     

河口近海桡足类休眠卵生态学研究进展

桡足类是水域生态系统的关键类群,在物质循环、能量流动和信息传递中起着重要作用.休眠卵是桡足类的重要生存策略,在抵抗不利环境、维持种群延续等方面起着重要作用.本文综述了河口近海桡足类休眠卵种类组成及其分布、休眠卵存活时间、休眠卵萌发率和沉积物中休眠卵丰度以及对水体的潜在补充量及其影响因素等.对河口近海桡足类休眠卵生态学研究提出了展望,以期为相关研究提供新的思路.     

枯林湾浮游桡足类生态研究

2000年7月至2001年7月的周年调查结果表明,粤东柘林湾浮游桡足类29属57种,其中,强额拟哲水蚤Para-ca;amis crassorpstris和短角长腹剑水蚤Ootjpma brevicomis为优势种,合计占浮游桡足类总个体数的66.7%.柘林湾是一个浮游桡足类相对丰富的海湾,年均总个体数达5.4×103ind.@m-3.浮游桡足类的种类数和总个体数均表现为湾外大于湾内的平面分布格局,周年变化基本上为单峰型,高峰期位于5～10月,最低谷位于冬季1月.     

胶州湾浮游桡足类时空分布

根据2003年1月至12月在胶州湾所获得的浮游生物样品,已鉴定浮游桡足类28种,幼虫、幼体6类.分析了该海区浮游桡足类的分布﹑时空变化及其与生态环境因子的关系,同相关历史资料进行了比较,结果表明,浮游桡足类的种类组成单纯,生态属性以暖温带、近岸低盐种类为主.浮游桡足类的丰度分布具明显的月份变化,高峰在7月份,为181.61个/m3,最低在12月份,为23.53个/m3,全年平均为71.42个/m3.浮游桡足类丰度的平面分布不均匀,最大丰度在5号站,为132.62个/m3,最小丰度在8号站,为40.45个/m3,丰度平面分布的变化趋势基本是湾北部海域大于湾南部海域.浮游桡足类丰度的时空分布,主要种类的季节更替,近20a来的变化趋势基本相同,高峰出现时间的差异,是受温度年季变化差异因素的影响.浮游桡足类丰度的时空分布与海水温度和盐度密切相关,与温度的关系更重要于与盐度的关系.并且用胶州湾的调察资料证实了浮游桡足类对浮游植物的依存关系,浮游植物为浮游桡足类的生长、繁衍提供了饵料.     

珠江口浮游桡足类的生态研究

根据2002～2003年珠江口12个航次的调查资料,分析了浮游桡足类种类组成、优势种演替和丰度的时空变化,探讨其影响因素。以表层盐度(S)变化将调查海域划分三个区域:I区(S<25)、Ⅱ区(2530)。结果表明:调查海域共出现桡足类65种,Ⅱ区和Ⅲ区的种类多于I区;桡足类的平均丰度为118ind·m^-3,三个区域之间的比较为Ⅱ区(165ind·m^-3)>I区(129ind·m^-3)>Ⅲ区(62ind·m^-3),春、夏季的丰度高于冬季;优势种有明显的时间和区域上的变化。I区9个航次的研究结果表明:I区桡足类种类较少;各月份之间的平均丰度差别大,由河口内往外呈增加趋势。盐度是影响珠江口桡足类种类组成和数量变化的主要因素。     

重金属对海洋桡足类的影响研究进展

桡足类是海洋浮游动物种群的主要组成部分和重要的初级消费者,重金属污染对其影响可通过食物链传递到其他海洋生物甚至人类。综述了近20 a来重金属对桡足类影响的研究进展,包括重金属对桡足类的毒性和生理效应,重金属在桡足类体内蓄积及桡足类体内重金属的食物链(网)传递。并指出今后的研究重点:桡足类体内致毒重金属的存在形式,重金属食物暴露对桡足类生理生化影响机理,以及重金属对桡足类生活史的影响。     

河北白洋淀的枝角类和桡足类

白洋淀在河北省中部,位于东经115°38′～116°07′,北纬38°43′～39°02′之间;是华北平原最大和最典型的淡水湖泊湿地.湖内浮游动物种类丰富,但不同时期由于种种原因其种类又存在着差异.笔者于2005～2007年曾17次对白洋淀8个样点枝角类和桡足类进行了调查.     

桡足类与硅藻相互作用的研究进展

硅藻对桡足类繁殖的影响是近年来海洋生态学的热点问题,主要体现在降低了桡足类的产卵和孵化成功率。其可能原因在于硅藻大量繁殖后由于缺乏某种关键营养物质或自身产生某种抑制物阻碍了桡足类繁殖过程。但目前现场、室内实验结果不一：室内实验结果显示硅藻对桡足类繁殖的抑制作用主要是因为缺乏必要的多不饱和酸（PUFAs）。而现场实验结果则表明硅藻可产生次级代谢产物（小分子量的醛类）阻碍桡足类卵的孵化。由于目前对这种硅藻．桡足类相互作用机制和影响程度尚不清楚,如果这一现象在自然海区中普遍存在,传统上关于“硅藻-桡足类-鱼类”的海洋经典食物链观点势必存在极大的缺陷。文章介绍了这一问题的目前研究进展和将来的研究前景。     

Copepod diapause and the biogeography of the marine lipidscape

Aim

One of the primary characteristics that determines the structure and function of marine food webs is the utilization and prominence of energy‐rich lipids. The biogeographical pattern of lipids throughout the ocean delineates the marine “lipidscape,” which supports lipid‐rich fish, mammal, and seabird communities. While the importance of lipids is well appreciated, there are no synoptic measurements or biogeographical estimates of the marine lipidscape. Productive lipid‐rich food webs in the pelagic ocean depend on the critical diapause stage of large pelagic copepods, which integrate lipid production from phytoplankton, concentrating it in space and time, and making it available to upper trophic levels as particularly energy‐rich wax esters. As an important first step towards mapping the marine lipidscape, we compared four different modelling approaches of copepodid diapause, each representing different underlying hypotheses, and evaluated them against global datasets.

Location

Global Ocean.

Taxon

Copepoda.

Methods

Through a series of global model runs and data comparisons, we demonstrated the potential for regional studies to be extended to estimate global biogeographical patterns of diapause. We compared four modelling approaches each designed from a different perspective: life history, physiology, trait‐based community ecology, and empirical relationships. We compared the resulting biogeographical patterns and evaluated the model results against global measurements of copepodid diapause.

Results

Models were able to resolve more than just the latitudinal pattern of diapause (i.e. increased diapause prevalence near the poles), but to also pick up a diversity of regions where diapause occurs, such as coastal upwelling zones and seasonal seas. The life history model provided the best match to global observations. The predicted global biogeographical patterns, combined with carbon flux estimates, suggested a lower bound of 0.031–0.25 Pg C yr^?1 of downward flux associated with copepodid diapause.

Main conclusions

Results indicated a promising path forward for representing a detailed biogeography of the marine lipidscape and its associated carbon flux in global ecosystem and climate models. While complex models may offer advantages in terms of reproducing details of community structure, simpler theoretically based models appeared to best reproduce broad‐scale biogeographical patterns and showed the best correlation with observed biogeographical patterns.

     

Photoperiodic control of adult diapause in the predacious mite, Amblyseius potentillae: repeated diapause induction and termination

ABSTRACT. Photoperiodic control of facultative reproductive diapause was examined in females of the phytoseiid mite, Amblyseius potentillae (Garman). Full diapause was induced by rearing the mites from egg to adult under short-day photoperiods. Egg-laying females, however, which had experienced a long-day photoperiodic regime during pre-imaginal development, could still be induced to enter diapause when they were transferred to a short-day regime. Diapause development proceeded slowly under a short-day photoperiod, but was accelerated under long days. During diapause development under short days the photoperiodic sensitivity of the females diminished gradually and ultimately disappeared completely. However, after completion of diapause, sensitivity to photo-period reappeared. A second diapause could be induced in post-diapause females under short-day photoperiods and completed again under long-day photoperiods. These results show that A. potentillae remains sensitive to diapause-inducing and diapause-averting daylengths during the adult stage and that a second diapause may be induced after completion of the first one.     

Molecular mechanism of diapause in insect (I) --Expression of diapause hormone gene and incubation temperature in embryonic stage of Bombyx mori

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The biology and morphology of the marine harpacticoid copepod Heteropsyllus nunni Coull, during encystment diapause

Heteropsyllus nunni Coull, a meiobenthic harpacticoid copepod is the marine crustacean to undergo a state of diapause within a cyst. A 12 month field study indicated H. nunni adults reached peak population densities in winter, with nauplii maturing in the spring, becoming adults by April or May.At the last stage of development, a mature but unmated adult, they begin to prepare for encystment diapause. The copepods remain within their cyst in a state of diapause for 3–4 months during the summer only. Studies on the effects of temperature and photoperiod suggested that these two environmental cues are not crucial for induction or termination of diapause. Low temperature delayed development and time to encystment, while high temperatures accelerated development, making the time to encystment shorter. There were males than females in the cysts in laboratory experiments. Upon excystment, the copepods mate, and females begin egg production within one week. Adults that have excysted and mated die after a few weeks of active reproductive effort. Nauplii go on to mature and begin the univoltine diapause/reproductive cycle.The copepods prepare for dormancy in two ways: they begin to produce and store two types of secretory products to be used in cyst construction; then they produce large quantities of lipid to be used as a nutrient supply throughout diapause. Histochemistry of the cyst-building material indicated the lower urosome is full of two chemically different products. Dorsally, there is a storage sac of proteinaceous material. The ventral sac of secretory product is a mucopolysaccharide. The copepod builds the spherical cysts in a matrix of small and large sand grains. The cysts fit tightly around the ventral portion of the animal in the its flexed position: however, there is a large space between the cyst and the sides of the copepod.Biochemical analysis of the cyst showed it is composed of an amino acid complex similar to collagenous material. Scanning electron microscopy revealed a complex of large cuticular pores located in the lower urosome and caudal rami. There are specific pores for secretion of the two cyst-building products.     

松毛虫赤眼蜂滞育诱导及解除条件研究

【目的】以柞蚕Antheraea pernyi卵为繁殖寄主,对松毛虫赤眼蜂Trichogramma dendrolim滞育诱导及解除条件进行研究,以解决赤眼蜂工厂化生产和大面积应用中面临的的中、长期储存问题。【方法】通过观测不同发育阶段(寄生柞蚕卵在26℃培养40、96和144 h)、滞育诱导温度(10、13和16℃)和诱导时间对松毛虫赤眼蜂滞育的影响,确定松毛虫赤眼蜂滞育诱导条件;通过观测滞育诱导温度和滞育后的贮藏温度对滞育解除的影响,确定松毛虫赤眼蜂滞育解除条件。【结果】在松毛虫赤眼蜂的不同发育阶段对其进行持续的低温刺激均能使其导入滞育,但以小幼阶段(26℃培养40 h)开始效果最佳,寄生卵在26℃培养40 h后,转入10℃和13℃下连续诱导31 d,滞育率可达100%和99.12%。滞育诱导温度和滞育后的贮藏温度对松毛虫赤眼蜂解除滞育所需时间和解除滞育后的羽化出蜂率有较大影响,10℃诱导滞育后置于1℃冷藏的赤眼蜂解除滞育所需时间最短,解除滞育后的羽化出蜂率和单卵出蜂数更高,更耐储存。此条件下冷藏约30 d开始打破滞育,在正常发育下温度下羽化出蜂,60 d羽化出蜂率达到95.24%,冷藏4个月后羽化出蜂率仍在60%以上,单卵出蜂数高于50头。【结论】松毛虫赤眼蜂最佳滞育诱导条件为26℃培养40 h后,转入10℃连续低温诱导31 d;最佳滞育解除条件为1℃低温储存,但储存期不能超过4个月。     

昆虫延长滞育的研究

持续时间达1年以上的滞育,称为延长滞育,延长滞育的诱导、维持、解除均不同于简单滞育(滞育期短于1年)。本论文系统阐述了昆虫延长滞育的类型、滞育诱导及解除的环境因子、延长滞育物候学和生物学特性,延长滞育的遗传学及延长滞育的生态学意义。延长滞育是昆虫生活史的重要组成部分,是一种普遍现象。     

二斑叶螨滞育特性的初步研究

诱导滞育实验表明 :短日照和低温是诱导二斑叶螨发生滞育的主要因子。测定我国天水种群 ,在 15℃条件下 ,诱导其滞育的临界日照长度为 9小时 4 2分 ,在每日 8小时光照条件下 ,诱导其滞育的临界温度为 15.5℃。解除滞育实验表明 :在每日 13小时的光照条件下 ,温度越高 ,解除越冬雌成螨滞育的速度越快 ;低温处理滞育雌成螨的时间越长 ,解除其滞育的速度也越快。     

Thermal response and reversibility of diapause in the eggs of Locusta migratoria

Abstract. Eggs of a local population of Locusta migratoria L. (Orthoptera: Acrididae) collected near Hirosaki (40.5^oN) entered diapause when incubated at temperatures between 20 and 35^oC. For diapause development the optimum temperature was 10^oC. The lower thermal threshold for post-diapause development was 14.7^oC. After chilling at 10^oC for 20 days, the rate of hatching varied with incubation temperature, being 0, 61% and 81% at 20, 25 and 30^oC, respectively. After chilling for 40 days or more, however, almost all eggs hatched at 20–30^oC. Diapause with a reduced intensity seemed to be eliminated easily by a high temperature of 25 or 30^oC.
When eggs chilled at 10^oC for 20 days were kept at 20^oC for 7 days or more before incubation at 25^oC, almost all eggs maintained diapause. Most eggs chilled at 10^oC for three 10 day periods separated by 3 days of warming at 25^oC failed to terminate diapause. Daily alternations of 10^oC (18 h) and 25^oC (6h) decreased the diapause-terminating effect of chilling. These facts suggest that diapause intensity can be restored if eggs chilled insufficiently are exposed to a moderately high temperature. This reversible change in diapause intensity would play an important role in maintaining diapause before winter.