Larval development and dispersal at deep-sea hydrothermal vents

Deep-sea hydrothermal vent communities exhibit an array of reproductive strategies. Although a few vent species undergo planktotrophic, high-dispersal modes of development, most exhibit relatively low dispersal, but probably free-swimming nonplanktotrophic development. This predominance of nonplanktotrophy may be largely a reflection of phylogenetic constraints on the vent colonizing taxa; intervent dispersal among these forms may be facilitated by reduced developmental rates in the cold abyssal waters away from the vents. It is proposed that for those vent species with nonplanktotrophic development, larval dispersal is a stepwise process with oceanic ridge axes serving as discrete dispersal corridors.     

环境和扩散对草地群落构建的影响

植物群落构建机制是生态学研究的热点之一。长久以来这个难题并没有得到很好的解释,且争议较多。生态位理论或中性理论,或是二者的共同作用,这样的结论在不同的研究中都有印证。以黄土高原子午岭地区的草地群落为例,对3种不同的草地群落(5a的弃耕地、阴坡和阳坡的草地)进行了野外群落学调查,采用Mantel test和主轴邻距法(PCNM)分析方法,研究了空间地理距离和环境资源差异对于草本植物群落分布的影响,结果表明:地理距离和环境差异共同解释了群落组成相似性的79.3%,剔除环境因子的影响,地理距离解释了群落组成相似性的33.8%;而剔除地理距离的影响,环境因子解释了群落组成相似性的14.2%。无论是生态位理论还是中性理论,其在黄土高原草本群落构建过程中都有作用,但中性理论扮演了更为重要的角色。     

Global dispersal of free-living microbial eukaryote species

The abundance of individuals in microbial species is so large that dispersal is rarely (if ever) restricted by geographical barriers. This "ubiquitous" dispersal requires an alternative view of the scale and dynamics of biodiversity at the microbial level, wherein global species number is relatively low and local species richness is always sufficient to drive ecosystem functions.     

Amphibians as indicators of early tertiary "out-of-India" dispersal of vertebrates

Sixty-five million years ago, massive volcanism produced on the India-Seychelles landmass the largest continental lava deposit (Deccan Traps) of the past 200 million years. Using a molecular clock-independent approach for inferring dating information from molecular phylogenies, we show that multiple lineages of frogs survived Deccan Traps volcanism after millions of years of isolation on drifting India. The collision between the Indian and Eurasian plates was followed by wide dispersal of several of these lineages. This "out-of-India" scenario reveals a zoogeographical pattern that might reconcile paleontological and molecular data in other vertebrate groups.     

Animal versus wind dispersal and the robustness of tree species to deforestation

Studies suggest that populations of different species do not decline equally after habitat loss. However, empirical tests have been confined to fine spatiotemporal scales and have rarely included plants. Using data from 89,365 forest survey plots covering peninsular Spain, we explored, for each of 34 common tree species, the relationship between probability of occurrence and the local cover of remaining forest. Twenty-four species showed a significant negative response to forest loss, so that decreased forest cover had a negative effect on tree diversity, but the responses of individual species were highly variable. Animal-dispersed species were less vulnerable to forest loss, with six showing positive responses to decreased forest cover. The results imply that plant-animal interactions help prevent the collapse of forest communities that suffer habitat destruction.     

Vermetid gastropods and intertidal reefs in Israel and bermuda

Small-rimmed intertidal reefs develop in the subtropical marine waters of Israel and Bermuda when erosion of exposed promontories is arrested by vermetid gastropods. The reefs in Bermuda are actively growing, wave-resistant biogenic structures, while those in Israel are limestone structures only encrusted by a relatively thin layer of vermetid shells cemented by coralline algae.     

From individual dispersal to species ranges: perspectives for a changing world

Dispersal is often risky to the individual, yet the long-term survival of populations depends on having a sufficient number of individuals that move, find each other, and locate suitable breeding habitats. This tension has consequences that rarely meet our conservation or management goals. This is particularly true in changing environments, which makes the study of dispersal urgently topical in a world plagued with habitat loss, climate change, and species introductions. Despite the difficulty of tracking mobile individuals over potentially vast ranges, recent research has revealed a multitude of ways in which dispersal evolution can either constrain, or accelerate, species' responses to environmental changes.     

杂夜蛾亚科2种幼虫形态记述（鳞翅目：夜蛾科）

详细记述了中国甜菜夜蛾Spodoptera exigua（Hübner） 和稻蛀茎夜蛾Seasamia inferens （Walker） 幼虫的形态特征,并提供了形态特征图。图2参9     

Monolayers and microbial dispersal

Aqueous films on terrestrial litter are inhabited by numerous microorganisms; the surfaces of such films are covered by monolayer-forming substances. The spreading pressure of the latter can result in transport of floating and submerged organisms to adjacent water films with clean surfaces. The clean surfaces, produced by rain or possibly dew, permit rapid vertical and horizontal dispersal of microorganisms onto newly fallen leaves and other plant materials.     

Effects of sesame nectar on longevity and fecundity of seven Lepidoptera and survival of four parasitoid species commonly found in agricultural ecosystems

Ecological engineering involves the use of plants to promote establishment,survival and efficiency of natural enemies in agricultural systems.Some plant species may be hosts or provide resources to some pest species.We assessed the risks and benefits of sesame(Sesamum indicum L.),as a nectar source for seven economically important Lepidopteran pest and four parasitoid species in a range of vegetable crop systems.Our results showed that the mean longevities of arthropod parasitoids Pteromalus puparum(L.),Encarsia sophia(Girault Dodd) and male Microplitis tuberculifer(Wesmael) were significantly extended when fed on sesame flowers compared to the water control.Sesame flowers had no effect on adult longevities and fecundities of six out of the seven Lepidoptera pest species tested except Plutella xyllostella(L.) females laid more eggs when fed on sesame flowers.It is likely that the increased fecundity is due to accessibility to nectar at the bottom of corolla because of their smaller body sizes.Our findings provide a first step towards better understanding of the risks and benefits of using sesame to implement ecological engineering for the management of vegetable pests.     

沙塘鳢胚胎和仔鱼发育的初步研究

对沙塘鳢（Odontobutis obscura）胚胎和仔鱼的发育进行了观察，描述了各发育阶段的形态特征。在22℃恒定条件下，沙塘鳢的胚胎发育历时528h，可分为28个发育分期。在整个发育过程中，各个器官如眼、耳囊、心脏、肾脏、肝脏、消化道、鳔、胸鳍和尾鳍等得到优先发育。     

Competition for dispersal in ant-dispersed plants

Two closely related and coexisting plants (Chenopodiaceae) of the Australian arid zone are adapted for seed dispersal by ants. These facultatively perennial shrubs persist in saltbush communities largely as a result of highly directional dispersal to ant mounds, where conditions are favorable for establishment and growth. The two species grow predominantly on mounds and compete for dispersal to these favorable microhabitats.     

Steroid control of longevity in Drosophila melanogaster

Ecdysone, the major steroid hormone of Drosophila melanogaster, is known for its role in development and reproduction. Flies that are heterozygous for mutations of the ecdysone receptor exhibit increases in life-span and resistance to various stresses, with no apparent deficit in fertility or activity. A mutant involved in the biosynthesis of ecdysone displays similar effects, which are suppressed by feeding ecdysone to the flies. These observations demonstrate the importance of the ecdysone hormonal pathway, a new player in regulating longevity.