双团棘胸蛙与棘腹蛙酯酶同工酶的比较研究

采用垂直聚丙烯酰胺凝胶电泳技术,对六盘水境内的双团棘胸蛙Paa yunnanensis与棘腹蛙P.boulengeri的肝、肠、胃、肺等4种组织中的酯酶(EST)同工酶进行了研究.结果 显示:两种蛙酯酶同工酶共有10条带,其中双团棘胸蛙EST同工酶有9条带,棘腹蛙EST同工酶有7条带,两种蛙EST同工酶存在较大的种间差异,同种蛙不同组织的酯酶(EST)同工酶迁移率、表达强度也不同.双团棘胸蛙酯酶同工酶酶谱较棘腹蛙的复杂.     

不同开口饵料对棘腹蛙幼蛙生长和存活的影响

用摇蚊Chironomidae midges幼虫、水蚯蚓Limnodrilus hoffmeisteri、蝇蛆Musca demestica、人工饵料作为棘腹蛙幼蛙的开口饵料饲养棘腹蛙幼蛙28 d,观察这些饵料对棘腹蛙幼蛙生长、存活情况的影响.结果表明,人工饵料组幼蛙生长速度最慢,存活率也最低(61.88%);摇蚊幼虫组的存活率最高(79.38%),生长最快,是棘腹蛙幼蛙适宜的开口饵料.     

鄂西棘腹蛙的生活习性及其食性的初步研究

棘腹蛙为山区流溪型种类,广食性,成蛙以捕食昆虫等动物性食物为主,蝌蚪主要摄食藻类等植物食物。棘腹蛙有显著消灭为害森林的动物(昆虫),其有益系数为68.31％。     

闽西北棘胸蛙生态调查及人工试养观察

棘胸蛙(Rana spinosa)在贵州、湖北、江苏、浙江、安徽、湖南、福建、广东、广西、江西等省均有分布,数量也多。棘胸蛙体大肉鲜,有较高的食用和药用价值。布尔恩格尔(Boulenger)曾于1892年、1899年先后曾记载在湖北、浙江、福建发现有棘腹蛙,1920年他又改定为棘胸蛙。丁汉波(1944—1956)在研究福建的两栖动物时曾对棘胸蛙有过报道,但目前国内对棘胸蛙系统的生态等方面的研究尚未很好地开展。刘承钊等(1961)曾建议设法在池塘中试养,而国内至今未见人工养殖棘胸蛙的报道。     

珍稀两栖动物——棘腹蛙及其保护

棘腹蛙是我国大型经济蛙类,近年,由于该蛙栖息地遭到严重破坏,及人类的大肆捕杀等因素,造成棘腹蛙种群数量严重下降,已被IUCN列为易危种.     

棘腹蛙肌肉嫩度及营养成分的初步分析

本文对棘腹蛙与牛蛙的肌肉嫩度作了比较,并测定了棘腹蛙肌肉的营养成分,且与甲鱼和田鸡的相应成分作了对照分析。结果表明,棘腹蛙肉质细嫩、营养价值高、风味较好,具有开发养殖前景。     

用功能生态学方法揭示峨眉髭蟾蝌蚪和棘腹蛙蟾蝌蚪共存的原因

采用功能生态学的研究方法,选取了3个指标(功能丰富度、功能定位和功能生态位的重叠程度)对峨眉山清音阁黑龙江中峨眉髭蟾蝌蚪和棘腹蛙蝌蚪共存的原因进行了解析。结果表明,峨眉髭蟾蝌蚪功能丰富度的实测值远远小于棘腹蛙蝌蚪。采用自助法随机抽样15和51个个体时,峨眉髭蟾蝌蚪的功能丰富度值显著小于棘腹蛙蝌蚪。同时,非参数多元方差分析的结果显示二者的功能定位存在显著差异。此外,二者功能生态位重叠程度的实测值与采用自助法计算所得值均极低。以上结果表明二者的功能生态位存在明显分化,表现为峨眉髭蟾蝌蚪个体较大,开口较小,眼间距较大,尾部发达且多采用背腹弯曲的游泳模式;而棘腹蛙蝌蚪开口较大,眼睛间距较小,尾部较为短小且多采用脊椎弯曲的游泳模式。鉴于功能性状可以反映生物体对生长环境的响应,推测两种蝌蚪主要栖息地的微生境也存在分化。     

湖北后河国家级自然保护区两栖爬行动物资源调查

2004年7月、2006年7～8月、2007年9月,对湖北后河国家级自然保护区的两栖爬行动物资源进行了调查.该保护区内现已知有两栖爬行动物73种,其中两栖动物29种,隶属于2目9科;爬行动物44种,隶属于2目9科.区系组成以东洋界种类占明显优势.资源量优势种两栖类有中华蟾蜍(Bufo g.gargarizans)、绿臭蛙(Odorrana margaretae)、泽陆蛙(Fejervarya multistriata)、棘腹蛙(Paa boulengeri)、崇安湍蛙(Amolops chunganensis);爬行类有王锦蛇(Elaphe carinata)、黑眉锦蛇(Elaphe taeniura)、乌梢蛇(Zaocys dhumnades)、福建竹叶青蛇(Trimeresurus stejnegeri).根据资源特点及保护现状,提出对保护区内两栖爬行动物的保护建议.     

棘腹蛙(Rana boulengeri Günther)早期胚胎发育与分期的研究

本文研究了湘西地区棘腹蛙（Ｒ．ｂｏｕｌｅｎｇｅｒｉＧ．）的早期胚胎发育与分期．用人工诱导排卵、人工授精的方法获得受精卵,在控制水温为（２３±０．５）℃下发育,棘腹蛙的胚胎发育从人工授精开始到蝌蚪的鳃盖完全闭合需要２６１ｈ;以胚胎形态变化和主要生理特征的出现为基础,该蛙早期胚胎发育可分为２５个时期．棘腹蛙发育过程中的形态特征和其它无尾两栖类相似,但在某些方面也呈现出与适应山地溪流环境有关的一些特点．     

中国两栖动物新纪录--多疣棘蛙的再证实

多疣棘蛙(Paa verrucospinosa(Bourret),1939)是Bourret于1937年根据越南沙巴采集到的标本订为棘胸蛙一新亚种[1],1939年他改订为新种[2]。寇治通等人1983年10月在云南省勐腊县景飘采到一只雌性成体蛙的标本,作为我国多疣棘蛙的新纪录发表[5]。但一直未得到承认[3,4,6~9]。笔者于2003年7月在云南省景洪市勐龙乡勐宋村、2004年8月在云南省勐腊县勐远镇艺班东村进行两栖动物调查时,采集到8号蛙类标本,经鉴定为蛙科棘蛙属多疣棘蛙(Paa verrucospinosa),这是中国两栖动物新记录,标本现保存于云南大学生命科学学院脊椎动物标本室,现报道如下。…     

Tea: Biological control of insect and mite pests in China

Tea is one of the most economically important crops in China. To secure its production and quality, biological control measures within the context of integrated pest management (IPM) has been widely popularized in China. IMP programs also provide better control of arthropod pests on tea with less chemical insecticide usage and minimal impact on the environment. More than 1100 species of natural enemies including about 80 species of viruses, 40 species of fungi, 240 species of parasitoids and 600 species of predators, as well as several species of bacteria have been recorded in tea ecosystems in China. Biological and ecological characteristics of some dominant natural enemies have been well documented. Several viral, bacterial, and fungal insecticides have been commercially utilized at large scale in China. Progress in biological control methods in conjunction with other pest control approaches for tea insect pest management is reviewed in this article. Knowledge gaps and future directions for tea pest management are also discussed.     

Taxonomic and nomenclatural revision of Sládeček's list of ciliates (Protozoa: Ciliophora) as indicators of water quality

A taxonomic and nomenclatural revision of Sládeek's et al. (1981) and Wegl's (1983) lists of ciliates (Protozoa: Ciliophora) as indicators of water quality has been performed. The original reference, important synonyms, and modern taxonomic literature are provided for each of the 378 taxa recognized. The results of this revision are summarized in a table which shows the correct (modern) name, author, and date of publication of each species as well as its saprobity, its saprobic valency, its indicative weight, and its saprobic index.     

Dynamics of Sundarban estuarine ecosystem: eutrophication induced threat to mangroves

Background

Sundarbans is the largest chunk of mangrove forest and only tiger mangrove land in the world. Compared to the rich species diversity and uniqueness, very few studies have so far been conducted here, mainly due to its inaccessibility. This study explores water quality, density of biomass, species diversity, phytoplankton abundance and bacterial population of a tidal creek in Sunderban estuary during the post and pre monsoon period of 2008-09.

Results

Phytoplankton community was observed to be dominated by diatoms (Biacillariophyceae) followed by Pyrrophyceae (Dinoflagellates) and Chlorophyceae. A total of 46 taxa belonging to 6 groups were recorded. Other algal groups were Cyanophyceae, Euglenophyceae and Chrysophyceae. Species diversity was highest in summer (March) and lowest in winter season (November) in all the sample stations indicating its close correlation with ambient temperature. Species evenness was fairly high in all five stations throughout the study period. Present study indicated that dissolved oxygen, nutrients and turbidity are the limiting factors for the phytoplankton biomass. The estuary was in eutrophic condition (Chlorophyll-a ≥10 μg/L) in winter. During the month of May phytoplankton biomass declined and at high salinity level (21.2PSU) new phytoplankton species take over, which are definitely better resilient to the high saline environment. Bio-indicator species like Polykrikos schwartzil, Dinophysis norvegica and Prorocentrum concavum points to moderately polluted water quality of the estuary.

Conclusion

Eutrophication as well as presence of toxic Dinoflagellates and Cyanophyceae in the tidal creek of Sundarban estuary definitely revealed the deteriorated status of the water quality. The structure and function of the mangrove food web is unique, driven by both marine and terrestrial components. But little attention has been paid so far to the adaptive responses of mangrove biota to the various disturbances, and now our work unfolds the fact that marine status of Sundarban estuary is highly threatened which in turn will affect the ecology of the mangrove. This study indicates that ecosystem dynamics of the world heritage site Sundarban may facilitate bioinvasion putting a question mark on the sustainability of mangroves.     

Potential allelopathic effects of the tropical legume <Emphasis Type="Italic">Sesbania virgata</Emphasis> on the alien <Emphasis Type="Italic">Leucaena leucocephala</Emphasis> related to seed carbohydrate metabolism

Allelopathy has been considered a key mechanism to explain the invasiveness of some species. It is well known that invasive plants can affect native plants by producing novel allelochemicals but some exotic plant species may be also sensitive to allelochemicals released by native species, providing a tool to reduce growth and impacts of invasive exotic species. Here, using growth chamber experiments we tested the mutual potential allelopathic effects of Sesbania virgata (a native dominant species) and the alien Leucaena leucocephala seeds. S. virgata was unaffected by seed leachates of L. leucocephala, indicating that, under lab conditions, this legume presents resistance to the phytotoxic compounds produced by seeds of this alien species. In contrast, germination and seedling growth of L. leucocephala were strongly affected by the phytochemicals produced by seeds of S. virgata. A delay in endospermic mobilization of storage carbohydrates (raffinose-family oligosaccharides and galactomannan) was observed in the alien species. These potential allelopathic effects could not be attributed sole to the presence neither of the phytoxic catechin nor of ABA in seed leachates of S. virgata. Our findings indicate that the in vitro behavior of S. virgata is consistent with its aggressiveness in natural environment and suggest sesbanimide as a potential candidate as implicated in the noxious effects of S. virgata on the alien species.     

Comet assay: a reliable tool for the assessment of DNA damage in different models

New chemicals are being added each year to the existing burden of toxic substances in the environment. This has led to increased pollution of ecosystems as well as deterioration of the air, water, and soil quality. Excessive agricultural and industrial activities adversely affect biodiversity, threatening the survival of species in a particular habitat as well as posing disease risks to humans. Some of the chemicals, e.g., pesticides and heavy metals, may be genotoxic to the sentinel species and/or to non-target species, causing deleterious effects in somatic or germ cells. Test systems which help in hazard prediction and risk assessment are important to assess the genotoxic potential of chemicals before their release into the environment or commercial use as well as DNA damage in flora and fauna affected by contaminated/polluted habitats. The Comet assay has been widely accepted as a simple, sensitive, and rapid tool for assessing DNA damage and repair in individual eukaryotic as well as some prokaryotic cells, and has increasingly found application in diverse fields ranging from genetic toxicology to human epidemiology. This review is an attempt to comprehensively encase the use of Comet assay in different models from bacteria to man, employing diverse cell types to assess the DNA-damaging potential of chemicals and/or environmental conditions. Sentinel species are the first to be affected by adverse changes in their environment. Determination of DNA damage using the Comet assay in these indicator organisms would thus provide information about the genotoxic potential of their habitat at an early stage. This would allow for intervention strategies to be implemented for prevention or reduction of deleterious health effects in the sentinel species as well as in humans. IITR Communication No. 2656     

Properties and Characterization of the Host Bacterium of Bacteriophage PM2

A marine bacterium, which acts as host for bacteriophage PM2 isolated from the same environment, has been characterized as a Pseudomonas species. This Pseudomonas cannot be assigned to any of the subgeneric categories or "groups" described by Stanier, Palleroni, and Doudoroff. The psychrophilic and halophilic nature of the organism and its requirement for NaCl suggest an indigenous marine origin.     

History of human settlement, cultural change and interference with the marine environment

Humans have been present in the Wadden Sea area since the end of the last ice age, but their perception of and interference with their marine environment has changed over time. In this paper, I will give an overview on the interactions between man and nature since the 6th millennium B.C., on the opportunities for human settlement as well as on restrictions posed by the maritime environment. Only after many centuries of passive adaptation did the local farming population begin to modify their immediate surroundings. They made a living as cattle breeders, supplemented this with fishing, hunting, weaving, salt production and peat digging. Efforts to transform the agricultural landscape did not start before the 11th century A.D., when the first dikes and canals were constructed. The consequences were profound. By the end of the Middle Ages, the dikes had become totally indispensable. The land under cultivation was perceived as a sacred inner world, conflicting sharply with the marine environment outside its flood-gates. This essentially dichotomous world-view held out until the 19th and early 20th centuries. As we will see, however, the actual settlement history had been marked by various gains and losses, by successes as well as by setbacks. Not only did humans destroy valuable natural resources, but they also created alternative habitats for novel species. I conclude that the initial tendency towards increasing natural and cultural diversity has been reversed during the last few centuries. Yet, mounting conservationist concerns may cause a turning-point.

An Anatomical Description of a Miniaturized Acorn Worm (Hemichordata,Enteropneusta) with Asexual Reproduction by Paratomy

The interstitial environment of marine sandy bottoms is a nutrient-rich, sheltered habitat whilst at the same time also often a turbulent, space-limited, and ecologically challenging environment dominated by meiofauna. The interstitial fauna is one of the most diverse on earth and accommodates miniaturized representatives from many macrofaunal groups as well as several exclusively meiofaunal phyla. The colonization process of this environment, with the restrictions imposed by limited space and low Reynolds numbers, has selected for great morphological and behavioral changes as well as new life history strategies.Here we describe a new enteropneust species inhabiting the interstices among sand grains in shallow tropical waters of the West Atlantic. With a maximum body length of 0.6 mm, it is the first microscopic adult enteropneust known, a group otherwise ranging from 2 cm to 250 cm in adult size. Asexual reproduction by paratomy has been observed in this new species, a reproductive mode not previously reported among enteropneusts.Morphologically, Meioglossus psammophilus gen. et sp. nov. shows closest resemblance to an early juvenile stage of the acorn worm family Harrimaniidae, a result congruent with its phylogenetic placement based on molecular data. Its position, clearly nested within the larger macrofaunal hemichordates, suggests that this represents an extreme case of miniaturization. The evolutionary pathway to this simple or juvenile appearance, as chiefly demonstrated by its small size, dense ciliation, and single pair of gill pores, may be explained by progenesis. The finding of M. psammophilus gen. et sp. nov. underscores the notion that meiofauna may constitute a rich source of undiscovered metazoan diversity, possibly disguised as juveniles of other species.     

Seasonal variation in feeding habits and diet selection by wild boars in a semi-arid environment of Argentina

The wild boar, Sus scrofa, was first introduced for hunting purposes in Argentina in 1906 and presently occupies a wide range of habitats. Understanding the food habits of invasive species is important for predicting the effects of animal food consumption on the environment and on human activities, such as farming. The wild boar is an omnivorous, opportunistic species whose diet is determined by the relative abundance of different types of foods. In general, the wild boar’s diet has been widely studied in the world, both as a native and invasive species, but little is known regarding food resource selection in the Monte Desert biome. Our study assessed the seasonal variation in the diet of wild boars, as well as the nutritional quality of consumed items. Further, we determined the diet selection of this species. Diet analyses were based on faecal samples collected over two seasons (wet and dry) in 1 year. Herbs were the most frequently consumed food item, with wild boars showing a selection for them in both seasons. The wild boar uses food resources according to seasonal availability (larger trophic niche breadth under higher plant diversity, as in the wet season). In turn, within each season, it selects items of high forage quality and high carbohydrate contents. In conclusion, this foraging strategy enables wild boar to maximize energy budget through food selection in order to survive in a semi-arid environment such as the Monte Desert.     

Use, exploitation and prospects for conservation: people and plant biodiversity of Naltar Valley, northwestern Karakorums, Pakistan

Very little research has been conducted in the Himalayan and Karakorum Highlands of northern Pakistan on the aspects of biodiversity and conservation. The present research was carried out within the scope of the Pakistan–German Research Project, Culture Area Karakorum which aims to highlight the Problems and Prospects of High-Mountain Research in northern Pakistan. Naltar Valley, IUCN Management Category no. 4, located in the western Karakorums, is a remote area with difficult access. The current venture is two-fold; first, it describes the floral biodiversity of this remote area in northern Pakistan and second, discusses its exploitation by various entities with certain management implications to follow. Collection of species, their preservation and dialogue with the local, rural communities offered information on the plant biodiversity, providing the first extensive list of flora at the primary-valley level including their altitude range, habit and month of occurrence. In total, 153 plant species belonging to 38 families and 113 genera have been recorded after extensive field research in the area. Dominance has been observed for Asteraceae, Polygonaceae, Saxifragaceae and Rosaceae. Twenty-four plant species from Naltar emerged as ethnobotanically important for local medicinal uses and some commercial uses. Indeed, Thymus serpyllum, Gentiana tianshanica, Stellaria graminea, Geranium wallichianum and Capparris spinosa are the most important medicinal plants and their demand has increased, leading to over-exploitation. Cedrus deodara has completely disappeared from Naltar and Willow Salix sp. has almost been eradicated, except in the sub-alpine belts. The diversity of plant species within this remote area is very important for its obvious contribution to a sound mountain ecosystem. Prior to the present venture, not much was known about the floral aspects of this mountainous region of northern Pakistan. Many species are new additions to the plant list in this area. The species are distributed within the altitude range of 1,700–4,000 m and above, and are further explored for their ethnobotanical uses. It is recorded that some species are extensively used by the indigenous communities, some plant collectors from the lowlands and foreigners as well. Extensive grazing, uprooting of plants and soil-slope erosion intensify the environmental problems. A few species are further used for curing diseases through direct usage or marketing in the lowlands. Unfortunately, due to minor local conflicts, the area has been given low priority for its inclusion in the development and conservation programmes going on in other parts of these mountains. On the other hand, hospitable populations have a greater potential for the success of conservation and the wise usage of programmes. Concerted efforts are required to broaden our understanding of the dynamics of floral values as well as local concepts in this remote part of the world, and to check species decline. For sustainable use, in situ and ex situ conservation, controlled harvesting and aforestation may be the solution. Further extensive field conservation/management research is needed.