Holding wild Snow crab,Chionoecetes opilio: effects of stocking density and feeding on survival and injury

In this study the effects of different stocking densities on survival, injury and weight of captive male snow crab were examined. The first experiment (I) was carried out in square plastic tanks (700 L) with stocking densities of 100 (L), 150 (M) and 200 kg m^?3 (H) for 30 days. In a second experiment (II) snow crabs were kept at a stocking density of 50 kg m^?3 and were either fed (F) or not fed (S) for the same period of 35 days. The last experiment (III), was carried out with stocking densities of 25 kg m^?3 for 21 days with two groups, one with inactivated claw and one without rubber bands, with three replicates per treatment. In the first experiment mortality (H = 27, M = 26 and L = 36%) and occurrence of injuries (H = 27, M = 20 and L = 16%) were high in all groups. The weight loss during the experimental period was; H = 15.3, M = 10.9 and L = 15.5 g, and was not significant different between the groups. In experiment II the mortality (F = 13% and S = 14%) and injuries were lower (F = 12% and S = 17%). The average weight increased in the fed treatment and decreased in the starved treatments. In the last experiment there was no mortality in any of the groups and the levels of injury were low (5% and 7%). The results show that adult male snow crab cannot be stored at densities equal to or higher than 25 kg m^?3 for 3 weeks without risk of mortality.     

Comparative Expression Analysis of Gametogenesis‐Associated Genes in Foetal and Adult Bubaline (Bubalus bubalis) Ovaries and Testes

This study was conducted to identify and analyse the expression of gametogenesis‐associated genes and proteins in foetal and adult buffalo gonads of both the sexes. Relative quantification of the genes was determined by qPCR and Western blotting. Immunohistochemistry was also performed for various gametogenesis‐associated proteins in foetal and adult gonads of both the sexes. We observed significantly (p < 0.05) increased expression of primordial germ cell‐specific, meiotic as well as genes associated with oocyte maturation and development in foetal ovaries as compared to the adult ones. However, significantly (p < 0.05) increased expression of proteins associated with oocyte maturation like GDF9 and ZP4 was found in adult ovaries, indicating temporal regulation of mRNA translation during oogenesis. Meiotic genes showed significantly (p < 0.05) increased expression in adult testes as compared to foetal testes and ovaries, indicating onset of meiosis at a later stage in spermatogenesis. In general, the expression of primordial germ cell‐associated as well as meiotic genes was higher in adult testes, indicating the increased biological activity in the organ. Immunohistochemistry revealed localized expression of gametogenesis‐associated proteins in ovarian follicles and seminiferous tubules of testes, while the surrounding somatic tissues were devoid of these proteins. The study gives an understanding of the sequential and temporal events of gene expression as well as mRNA translation during male and female gametogenesis. It could also be concluded that follicles and seminiferous tubules are the functional units of the female and male gonads, respectively, and their function could be enhanced by appropriate chemical and genetic intervention of the somatic tissue immediately surrounding them. This assumes importance in the context that buffalo attains sexual maturity at an older age of 2–3 years and have smaller ovaries with lesser number of primordial follicles in comparison with cattle, which is suggested to be the main reason of their poor breeding performance.     

体重决定猪回肠内的蛋白吸收率

<正>近期伊利诺伊大学的J.A.Almeida博士、 Hans H.Stein博士以及Carsten Pedersen博士联手展开体重对于标准化回肠蛋白质和氨基酸吸收率的影响试验,结论证明,20 kg以下的仔猪回肠对于粗蛋白和氨基酸的吸收率比20~50 kg的育成猪和50~110 kg的育肥猪低。而且同一猪群的不同猪只也表现出吸收率的差异性。例如,在测定的300只仔猪中粗蛋白和氨基酸的吸收率     

Der Einfluß verschiedener Schädlingsbekämpfungsmittel auf Eiparasiten der GattungTrichogramma (Hym.,Trichogrammatidae)

Zusammenfassung Um den Einfluß verschiedener Insektizide und Fungizide auf Schlupfwespen der GattungTrichogramma zu prüfen, wurde deren Parasitierungsleistung bei Dauerkontakt mit dem betreffenden Mittel untersucht. Mit unbehandelten Apfelzweigen wurden solche verglichen, die mit den Fungiziden Dithane, Orthozid 50 und Ferbam F 40 bzw. den Insektiziden Ryania, Basudin R, Dipterex, Thiodan oder Metasystox gespritzt waren. Das Alter der Rückstände betrug 0, 24 bzw. 72 Stunden.Alle drei genannten Fungizide reduzierten die Parasitierung in den verschiedenen Varianten erheblich.Das spezifisch gegen Tortriziden wirkende Ryania zeigte praktisch keine toxische Wirkung. Die Anzahl der parasitierten Eier lag entweder gleich hoch wie bei den unbehandelten Kontrollen oder in einem Fall sogar erheblich höher.Die übrigen 4 Insektizide töteten die Schlupfwespen in kurzer Zeit ab, so daß in keinem Fall eine Parasitierung erzielt werden konnte.Noch nicht abgeschlossene Lebensdauerversuche bestätigen die erzielten Ergebnisse.Die Möglichkeiten und Probleme einer gemeinsamen Anwendung vonTrichogramma und Schädlingsbekämpfungsmitteln im Obstbau werden diskutiert.

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Summary To examine the influence of various insecticides and fungicides upon egg-parasites of the genusTrichogramma, their efficiency of parasitization at permanent contact with the concerning pesticide was checked. With untreated applebranches were compared those ones, which were treated with the fungicides Dithane, Orthozid 50 or Ferbam F 40 and the insecticides Ryania, Basudin R, Dipterex, Thiodan or Metasystox resp.All three fungicides reduced the parasitization in the different variations considerably.Ryania, which shows a specific effect against tortricides, had no toxical influence on,Trichogramma.The other four insecticides killed the parasites within a short time, so that in no case a parasitization could be achieved.Investigations concerning the duration of life confirmed the result of the parasitization investigations.The possibilities and problems of a combined application ofTrichogramma and pesticides in apple orchards are discussed.

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Dem Leiter des Instiltutes für Biologische Schädlingsbekämpfung, Herrn ORR. Dr. J. Franz bin ich für wertvolle Hinweise und jederzeitige Hilfe dankbar. — Durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Untersuchungen über die Entwicklung von Vorratsschädlingen an Früchten einheimischer Bäume und Sträucher

Zusammenfassung In Laboratoriumsuntersuchungen wurde die Eignung von sechs auch im Winter im Freien vorkommenden Wildfrüchten als Entwicklungs- und Fraßmedium für zehn Vorratsschädlinge getestet.Unbeschädigte Früchte von Stieleiche (Quercus robur), Roteiche (Qu. borealis), Roßkastanie (Aesculus hippocastanum) und Buche (Fagus sylvatica) konnten von keiner der geprüften Käfer- und Mottenarten befallen werden.An oder in beschädigten oder geschälten Früchten von Stieleiche und Buche konnten sich jeweils sieben Vorratsschädlinge entwickeln. Am wenigsten waren Hagebutte und Roteichel als Entwicklungsmedium geeignet.Die Schlüpfrate lag fast immer unter der in der Kontrolle. Nur beiSitophilus granarius schlüpften aus Stieleicheln mehr Imagines als aus Kontrollweizen.Das breiteste Nahrungsspektrum hatten im VersuchOryzaephilus surinamensis, Stegobium paniceum, Ephestia kuehniella undPlodia interpunctella mit je 5 der 6 getesteten Wildfrüchte.Die Buchecker bot allgemein die beste Entwicklungsmöglichkeit. Nur die Arten mit Innenbefall (Sitophilus granarius, S. oryzae undSitotroga cerealella) konnten an ihr keine neue Generation aufbauen.Der Einfluß auf die Entwicklungsdauer war je nach Wildfrucht und Schädling sehr unterschiedlich. Am wenigsten wich sie beiEphestia kuehniella von der normalen Dauer (an einem Gemisch aus Haferflocken, Weizenkleie und Glyzerin) ab.Da Vorratsschädlinge relativ häufig im Freiland gefunden werden können, vor allem in der Nähe von Silos und anderen Vorratslagern, ist nicht auszuschließen, daß Wildfrüchte ihnen eine zeitweise Überlebensmöglichkeit bieten und so, wenn auch sicher relativ selten, als Infestationsquelle dienen können.

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Investigations about the development of stored products insects at fruits of indigenous trees and shrubs

In laboratory experiments the suitability of six fruits of indigenous trees and shrubs, which are also available in the field during wintertime, was tested as food and development medium for ten stored products insects.Undamaged fruits of oaks (Quercus robur andQu. borealis), horse chestnuts (Aesculus bippocastanum) and beech (Fagus sylvatica) could not be attacked by any of the tested beetles and moths.Damaged or peeled fruits ofQu. robur andF. sylvatica, however, served as development medium for seven pests. The least fitted substrates were hipberries (Rosa canina) and acorns ofQu. borealis.The number of adults emerging from the wild fruits was normally lower than that from control mediums. An exception was found inSitophilus granarius developing in acorns ofQu. robur. Oryzaephilus surinamensis, Stegobium paniceum, Ephestia kuehniella andPlodia interpunctella had the broadest food spectrum with five fruits each.The beechnut offered the best possibilities for development. Only those insects living inside of seeds (Sitophilus granarius, S. oryzae andSitotroga cerealella) were not able to form a new generation in this fruit.The influence upon the length of the development period was different according to fruit and pest species. The slightest difference, compared with a normal medium (rolled oat, wheat bran and glycerine) was found in the mediterraneum flour moth (E. kuehniella).As stored products insects can be found relatively often in outdoor biotopes, especially in the surrounding of silos or stores, it can not be excluded that fruits of wild plants may offer—at least for a certain period—a possibility for survival. Thus they may act from time to time as a source of infestation.

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Mit 2 Abbildungen und einer Tabelle

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Herrn Prof. Dr.J.M. Franz zum 75. Geburtstag gewidmet.     

Estimates of stem wood increments in forest resources: comparison of different approaches in forest inventory: consequences for international reporting: case studyof European forests

Key message

Quality and reliability of forest resource assessments depend on the ability of national forest inventories (NFIs) to supply necessary and high-quality data. Over the last decades and especially since the 1990s, the NFIs in European countries have been rapidly developing. Possibilities for obtaining reliable and accurate data on annual increment from different inventory types were evaluated, and sample-based inventories have been found to be superior to standwise inventories in providing reliable data. Simplified methods may be employed when increment cannot be directly estimated from inventory data.

Context

An increasing intensity of forest resource use requires more accurate, detailed and reliable information, not only on forest area and growing stock but also on forest stand productivity, wood increment and its components.

Aims

The main objectives were to assess the capacities of forest inventories, the methods used for estimation of gross increment and its components and their accuracy and to demonstrate an effective method for estimation of increment when direct inventory methods are not available.

Methods

Data about national forest inventory methods were obtained from 30 responses to a questionnaire, distributed amongst national correspondents of all European countries; reports of COST Actions E43 and FP 1001, databases of Temperate and Boreal Forest Resource Assessment (TBFRA) 2000 and State of Europe’s Forests (SoEF) 2011 were used as well. Analysis and comparison of results from different forest inventories were used for evaluation of data reliability. Relationships between growing stock and gross increment in European forests were also analysed, and corresponding models were proposed.

Results

Seventy-nine percent of European forest area is covered by national forest inventories (NFIs) based on sampling methods and the rest on stand-level inventory and other inventory methods. Data obtained by aggregating standwise data usually underestimate growing stock by 15–20 % and gross increment even more. Almost half of the European forest area (47 %) is monitored using permanent plots, measured twice or more, allowing the estimation of gross increment and its components to be made directly.

Conclusion

Implementation of NFIs based on sampling methods, especially with permanent plots, resulted in an improvement of data quality and in most cases an increase of growing stock and gross increment. The estimation of natural losses is the weakest link in today’s NFIs and in the current assessment of European forest resources. The proposed default values for gross increment and its components is an option to be used in countries not having NFI at all or those which have started it only recently.

     

Tree planting for poverty reduction in less-favoured areas of the Ethiopian highlands

This paper assesses the potential impact of planting of eucalypt trees as a strategy to reduce poverty in a less-favoured area of the highlands of Ethiopia. Results from simulations with a bio-economic model for a less-favoured case study area in the highlands are combined with survey data at community, household and plot level to assess how general the results of the bio-economic model are. Application of the bio-economic model shows clearly that land degradation, population growth, stagnant technology and drought threaten food security. Household welfare and land quality are deteriorating rapidly in the area and interventions are urgently needed to avoid human disaster. Planting of eucalypts on land unsuitable for crop production may substantially increase household incomes if market outlets for trees can be found. Tree planting will not have severe negative effects on food production or land conservation. A policy combining promotion of tree planting and conservation of cropland may achieve win-win benefits in terms of increased household incomes as well as more sustainable land-use. Analysis of survey data from the Amhara Region of Ethiopia reveals that there is a large area of land that is unsuitable for crop production located close to all-weather roads in the less-favoured areas of the region. Few trees have been planted on this type of land up to now. The past policy seems to have discouraged tree planting except on homestead plots that are more suitable for food crops. This paper reports part of the IFPRI/ILRI project ‘Policies for Sustainable Land Management in the East African Highlands’. These two agencies have provided funds and logistical support for the work. The Norwegian Ministry of Foreign Affairs has provided funds for this research in the Amhara Region in Ethiopia. The authors also draw on earlier work funded by Research Council of Norway. Any correspondence should be directed to the first author.     

Der Einfluß von Außenfaktoren auf das Wanderverhalten der Deutschen Schabe,Blattella germanica (L.) (Blattodea,Blattellidae), in einer Mülldeponie

Mass propagation of the German cockroach in refuse tips may result in an increased emigration of this species into the surrounding area of the tip and thus in a heavy infestation of nearby buildings. Therefore, knowledges about the migration behavior are important when refuse tips are managed or projected. The influence of several environmental factors (as sun, day time, wind, temperature, season, light intensity) on the running behavior of the German cockroach was investigated under outdoor conditions. The most important results are as follows:

1. The reaction of young larvae (especially of L₁ and L₂) on the investigated factors differs considerably from that of older larvae and adults. As the young larvae do not emigrate, their behavior can be neglected in respect to the questions discussed here.
2. During sunshine, the position of the sun is primarily responsible for the direction of the migration. The highest percentage of the cockroaches walks directly towards the sun or a few grade right and left from the sun. When the sun is covered by clouds, the variation in the running direction is very high and many cockroaches migrate even into the direction opposite to the sun.
3. From morning to evening, the main migration direction is shifting from east to west, following the position of the sun.
4. Wind direction (at speeds of less than 5 m/sec.) and temperature (within the activity range of the cockroaches from approximately 18 to more than 30°C) have no recognizable influence upon the migration direction.
5. The clearest reaction of the running cockroaches towards the position of the sun was noticed during the main migration-time in the year (June and July).
6. The results of these investigations confirm former findings made in the field during a mass emigration of the German cockroach from a refuse tip.

     

A Comparison of the Effects of Two Prey Enrichment Media on Growth and Survival of Pacific Bluefin Tuna,Thunnus orientalis,Larvae

Three experiments were conducted to investigate the growth, survival, and standardized cohort biomass of Pacific bluefin tuna, Thunnus orientalis, larvae fed nutritionally enhanced prey during the first week of feeding using two commonly used, commercially available enrichment media, AlgaMac Enrich and Marine Glos. T. orientalis larvae exhibited exponential growth in standard length and dry weight. The daily specific growth rates in length and weight are the first reported for T. orientalis larvae and the averages ranged from 3.8 to 4.1% and 27.5%, respectively, for larvae in the AlgaMac treatment and from 4.1 to 6.1% and 31.5%, respectively, in the Marine Glos treatment. Average daily growth rates in length ranged from 0.16 to 0.23 mm/d for larvae in the AlgaMac treatment and from 0.17 to 0.27 mm/d for those in the Marine Glos treatment. Daily growth rates in length were similar to those reported for other tuna larvae reared in the laboratory but slower than most published estimates for larval tunas in situ at similar water temperatures. Mean prey number per gut was positively associated with mean prey level in the tank. Both enrichment media appear to be good sources of nutritional improvement of planktonic prey for T. orientalis larvae.