东方大黄蜂的表皮异源移植试验

将东方大黄蜂（胡蜂）蛹或幼蜂的棕色表皮层连同含有黑色素的皮细胞层、黄色表皮层及相连的产生黄嘌呤的皮细胞层割下，换化后植入原来的黄蜂体上（原来是黄色的部分用棕色替代，棕色的用黄色替代）。然后将蛹放回原来的子脾中，幼蜂放入一特殊的培养皿中，让其复原和发育。共对200个不同时期的蛹和50只幼蜂进行了试验。结果显示，存活的最主要是将羽化的蛹（差1—2天就羽化的蛹），早期的蛹和幼蜂均死亡。总共有约5％的蛹存活，幼蛹无一存活。在存活的蛹中，棕色表皮植入黄色区域中的不但成活了，而且还保留了棕色色彩。相反，黄色表皮在植入到棕色区域的几天后，就丢失了黄色及膜片。经过表皮异源移植的大黄蜂寿命极短，一般仅几星期。羽化后较敏感，攻击性强，但行走、飞行都很正常[动物学报51（6）：1146—1150，2005]。     

Diseases and Injuries Associated with Mortality of Hatchery Reared Baltic Cod (Gadus morhua L.) Larvae

A cod hatching plant was established in 1992 on the island of Bornholm in the Baltic Sea in order to elucidate the possibilites for restocking of cod fry in this brackishwater system. The disease prevalence in 3 batches of hatchery-reared yolksac larvae from the Baltic cod (Gadus morhua L.) was monitored during the posthatch period. High prevalences of bacteriosis/mycosis, lordosis/scoliosis, injuries and protozoan endoparasitism were recorded. Vibrio sp. and Vibrio anguillarum serovar 04, 06, 08 in addition to nontypable strains and saprolegniaceous fungi were isolated from the larvae. The dinoflagellate-like endoparasites were located in the yolksac of the cod larvae.     

Migration strategies of the Baltic dunlin: rapid jump migration in the autumn but slower skipping type spring migration

Migration during spring is usually faster than during autumn because of competition for breeding territories. In some cases, however, the costs and benefits associated with the environment can lead to slower spring migration, but examples are quite rare. We compared seasonal migration strategies of the endangered Baltic population of the dunlin Calidris alpina schinzii using light‐level geolocator data from 26 individuals breeding in Finland. Autumn migration was faster, with individuals showing a ‘jump’ and ‘skipping’ migration strategy characterised by fewer stationary periods, shorter total stopping time and faster flight. Spring migration was slower, with individuals using a ‘skipping’ strategy. The duration of migration was longer for early departing birds during spring but not during autumn suggesting that early spring migrants are prevented from arriving to the breeding areas or that fueling conditions are worse on the stopover sites for early arriving individuals. Dunlins showed high migratory connectivity. All individuals had one long staging at the Wadden Sea in the autumn after which half of the individuals flew 4500 km non‐stop to Banc d’Arguin, Mauritania. The other half stopped briefly on the Atlantic coast on their way to Mauritania. One bird wintered on the coast of Portugal. Nine individuals that carried geolocators for two years were site faithful to their final non‐breeding sites. Based on the strategies during the non‐breeding period we identified, Baltic dunlin may be especially vulnerable to rapid environmental changes at the staging and non‐breeding areas. Consequently, the preservation of the identified non‐breeding areas is important for their conservation.     

Post-fledging migration of common murres Uria aalge in the Baltic Sea: management implications

In this study of common murre Uria aalge chicks, at Slora Karlsö in the Baltic Sea (Sweden), we used two data sets to investigate the post-fledging migration to learn more on potential threats from human activities. Firstly, we radio tracked 12 chicks on average 5.1 h during their first night at sea, after jumping from the breeding cliffs in early July. Their average speed was 1,9 km h-'and all chicks swam in a similar direction (SW) with a mean bearing of 235°. By searching an area of ca 400 km2 further off the island between two and six days after the radio tracking, we concluded that they did not stop, even temporarily, within 40 km off the island, but had continued the swimming migration. Our second data set was made up by 400 recoveries of ringed chicks. Only those recovered within eight months after fledging (until February) were included. Two birds recovered at the Polish coast in the beginning of August had moved on average 10.7 and 12.3 km day-'(i.e. 0.45-0.51 km h-). In August, all chicks, except one, were found south of Gotland > 70 km away. The average distance to the recovery sites in. August was 253.5 km (n = 11). The pattern of distribution of birds reported in September. October and during the winter period from November to February was about the same as in August. The average direction from the colony lo the recovery sites was S to SW. Important findings from nature management perspective are: 1) our data suggest that the route of the chicks at least partly coincide with ship routes with at least 42000 passages each year. Hence, there is a potential for a great part of the common murre population to get in contact with oil spillage at this stage, notably in the first half of July. 2) From the 400 reported recoveries of ringed chicks we concluded that the most important over wintering areas are around Bornholm and the Bay of Gdansk. Hence, these are the most likely areas for conflicts with the fishery and oil spillage during the winter.     

Early life migration patterns of Baltic Sea pike Esox lucius

This study investigated the movement patterns of Baltic Sea pike Esox lucius in Matsalu Bay, Estonia, using otolith microchemistry. Migration patterns of E. lucius were remarkably diverse, but distinct groups were evident. Of the E. lucius analysed (n = 28), 82% hatched in fresh water and 74% of them left this biotope during the first growth season.     

Oxygen and carbon isoscapes for the Baltic Sea: Testing their applicability in fish migration studies

Conventional tags applied to individuals have been used to investigate animal movement, but these methods require tagged individuals be recaptured. Maps of regional isotopic variability known as “isoscapes” offer potential for various applications in migration research without tagging wherein isotope values of tissues are compared to environmental isotope values. In this study, we present the spatial variability in oxygen () and dissolved inorganic carbon (δ¹³C_DIC) isotope values of Baltic Sea water. We also provide an example of how these isoscapes can reveal locations of individual animal via spatial probability surface maps, using the high‐resolution salmon otolith isotope data from salmon during their sea‐feeding phase in the Baltic Sea. A clear latitudinal and vertical gradient was found for both and δ¹³C_DIC values. The difference between summer and winter in the Baltic Sea values was only slight, whereas δ¹³C_DIC values exhibited substantial seasonal variability related to algal productivity. Salmon otolith δ¹⁸O_oto and δ¹³C_oto values showed clear differences between feeding areas and seasons. Our example demonstrates that dual isotope approach offers great potential for estimating probable fish habitats once issues in model parameterization have been resolved.     

Changes in leucocyte migration after renal transplantation

The leucocyte migration test, an in-vitro measure of cellular immunity, has been used to follow the changes in cell-mediated hypersensitivity to kidney and histocompatibility antigens in three patients after renal transplantation.Inhibition of leucocyte migration, indicating strong sensitization to the antigens used, occurred in each patient, starting five to seven days after transplantation. Satisfactory renal function had not been established in any of the patients at this time. In one case inhibition of leucocyte migration persisted almost continuously until the 24th day and was associated with poor renal function proved histologically to be due to rejection. Treatment with increased dosage of prednisone was associated with a rapid reversion to normal of the migration index and improvement in renal function. Later, inhibition of migration occurred again, and shortly afterwards the graft ceased to function. In the other two cases the migration index became normal without alteration in immunosuppressive therapy and a satisfactory diuresis followed. It is suggested that this simple test should prove useful in the specific diagnosis of rejection and in control of immunosuppressive therapy.     

The Egg Abundance of Eastern Baltic Cod Gadus morhua callarias (Gadidae) in the 20th Century as a Population Status Indicator

Journal of Ichthyology - Data on the egg abundance of cod Gadus morhua callarias in the ichthyoplankton of deepwater basins of the Baltic Sea in 1903–2000 are presented. The maxima of the...     

Localisation of Nursery Areas Based on Comparative Analyses of the Horizontal and Vertical Distribution Patterns of Juvenile Baltic Cod (Gadus morhua)

Knowledge of the spatial distribution of juvenile cod is essential for obtaining precise recruitment data to conduct sustainable management of the eastern and western Baltic cod stocks. In this study, the horizontal and vertical distribution and density patterns of settled juvenile 0- and 1-group Baltic cod are determined, and their nursery areas are localised according to the environmental factors affecting them. Comparative statistical analyses of biological, hydrographic and hydroacoustic data are carried out based on standard ICES demersal trawl surveys and special integrated trawl and acoustic research surveys. Horizontal distribution maps for the 2001–2010 cohorts of juvenile cod are further generated by applying a statistical log-Gaussian Cox process model to the standard trawl survey data. The analyses indicate size-dependent horizontal and distinct vertical and diurnal distribution patterns related to the seabed topography, water layer depth, and the presence of hydrographic frontal zones (pycnoclines) as well as intraspecific patterns in relation to the presence of adult cod. The extent of the nursery areas also depends on the cod year class strength. Juvenile cod (≥3 cm) are present in all areas of the central Baltic Sea (CBS), showing broad dispersal. However, their highest density in the Baltic Basins is found at localities with a 40–70 m bottom depth in waters with oxygen concentrations above 2 ml O₂.l⁻¹ and temperatures above 5°C. The smallest juveniles are also found in deep sea localities down to a 100 m depth and at oxygen concentrations between 2–4 ml O₂.l⁻¹. The vertical, diurnally stratified and repeated trawling and hydroacoustic target strength-depth distributions obtained from the special surveys show juvenile cod concentrations in frontal zone water layers (pycnocline). However, the analyses indicate that in the CBS, juvenile cod of all sizes do not appear to aggregate in dense schooling patterns, which differs from what has been reported from the North Sea.     

Interrelationships in experiments in vitro between the migration activity of leukocytes and RNA and DNA synthesis]

The following correlations were revealed in the parallel study of leukocyte migration in vitro in the presence of a specific antigen and of spontaneous RNA and DNA synthesis in the cultured lymphocytes: 1) a direct correlation between the RNA and DNA synthesis in lymphocytes; 2) a close correlation between the antigen-induced migration and the levels of RNA and DNA synthesis. The effect of the antigen was evidenced by the inhibition or stimulation of leukocyte migration. A high ratio of RNA synthesis to DNA synthesis corresponded to the migration inhibition and a low one--to the migration stimulation. The ratio value varied mainly on account of the changes in the level of DNA synthesis. Participation of T and B cells in the regulation of the antigen-induced leukocyte mobility is discussed.     

Cytomechanics of cell deformations and migration: from models to experiments

A cytomechanical model bas been proposed to analyse cell-cell interactions and cell migration through chemotaxis. We consider as the leading assumption that the cell cortical tension is locally modified by the protrusive activity of neighbour cells and binding of chemoattractant molecules to membrane receptors respectively. The model derives from the one initially proposed by Alt and Tranquillo (1995), which successfully describes experimentally observed cyclic autonomous cell shape changes. It is based on force balance equations coupling intracellular hydrostatic pressure and cell cortex contraction. Considering the protrusive dynamics of L929 fibroblats observed by videomicroscopy, we simulated the influence of neighbouring protrusions on a cell spontaneous pulsating behaviour. We further investigated the role of an extracellular gradient as another kind of external stimulus. The model illustrates how binding of chemoattractant molecules can induce a cell morphological instability that, above an intracellular stress threshold, will break the cell-substratum attachment. As a result, realistic cell chemotaxis can be simulated.     

Inter-species transplantation and migration of primordial germ cells in cyprinid fish

Primordial germ cells (PGCs) are the only cells in developing embryos that can transmit genetic information to the next generation. PGCs therefore have considerable potential value for gene banking and cryopreservation, particularly via production of donor gametes using germ-line chimeras. In some animal species, including teleost fish, the feasibility of using PGC transplantation to obtain donor-derived offspring, within and between species, has been demonstrated. Successful use of PGC transplantation to produce germ-line chimeras is absolutely dependent on the migration of the transplanted cells from the site of transplantation to the host gonadal region. Here, we induced germ-line chimeras between teleost species using two different protocols: blastomere transplantation and single PGC transplantation. We evaluated the methods using the rate of successful migration of transplanted PGCs to the gonadal region of the host embryo. First, we transplanted blastomeres from zebrafish, pearl danio, goldfish, or loach into blastula-stage zebrafish embryos. Some somatic cells, derived from donor blastomeres, were co-transplanted with the PGCs and formed aggregates in the host embryos; a low efficiency of PGC transfer was achieved. Second, a single PGC from the donor species was transplanted into a zebrafish embryo. In all inter-species combinations, the donor PGC migrated toward the gonadal region of the host embryo at a comparatively high rate, regardless of the phylogenetic relationship of the donor and host species. These transplantation experiments showed that the mechanism of PGC migration is highly conserved beyond the family barrier in fish and that transplantation of a single PGC is an efficient method for producing inter-species germ-line chimeras.     

Effects of the swimbladder parasite Anguillicola crassus on the migration of European silver eels Anguilla anguilla in the Baltic Sea

In a mark–recapture study in 2006, migrating European Anguilla anguilla silver eels were caught, tagged and released in the Baltic Sea and recaptures in commercial pound nets examined for possible effects on migration of infection with the swimbladder parasite Anguillicola crassus . The overall recapture rate was 36%. The prevalence of infection was lowest at the northernmost sampling site. There were no significant differences between infected and uninfected A. anguilla in condition indices, body fat content and estimated migration speeds. Parasite infection intensity levels were significantly negatively correlated with times and distances covered between release and recapture, but did not correlate with migration speed. It appears that more heavily infected A. anguilla were relatively more vulnerable to recapture in pound nets. It is hypothesized that parasite-induced damage to the swimbladder inhibited vertical migrations and infected A. anguilla tended to migrate in shallower coastal waters, relatively close to the shore.     

The control of foot formation in transplantation experiments with hydra viridis

The results of three groups of experiments on the control of foot (basal disk) differentiation in Hydra viridis are well'; predicted by mathematical models of remarkable simplicity. In each of the experiments, a group of cells, called the actor, may or may not form a foot. The probability of foot formation is influenced by actor-specific properties and by properties of the rest of the animal, which may be called the setting.A natural interpretation of the mathematical models is that the actor forms a foot or not according to the balance of an inhibition of foot formation determined by the setting, and a critical inhibition level or “threshold”, an assumed actor characteristic. Threshold and inhibition are assumed to be normal random variables, the means of which depend on the parameters of the experiment. A foot is assumed to form in an individual case if the threshold is greater than, the inhibition.When transformed to a probit or logit scale, as described in the text, the mean intensity of inhibition appears to increase linearly with the quantity of foot tissue and to decrease linearly with increasing distance from the foot end of the hydra's body axis. The mean level of the threshold appears to increase linearly with time during which actor tissue is removed from inhibitory influences, but varies nonlinearly with position within the hydra.The inhibition-threshold models are tested here through statistically more tractable but numerically indistinguishable models of different mathematical form. If interpreted directly these models suggested that the odds that a foot will form are the product of an actor-determined scalar and a setting-determined scalar. The logarithms of these scalars are linear functions of the experimental parameters.     

Eutrophication in the Baltic Sea

Fish consumption is increasing globally. Overfishing puts pressure on fisheries, but aquaculture provides an alternative to satisfy the growing need for seafood. However, nutrient emissions from aquaculture contribute to eutrophication, and raising fish from the top of the food chain is inefficient. Here we use the approach of industrial ecology and report ImPACT decomposition analysis of the drivers of nutrient emissions to the Baltic Sea from rainbow trout aquaculture in Finland during 1980?2007. During this period, the nitrogen load studied increased markedly and was 522 tonnes in 2007. The phosphorus load quadrupled and then returned to its original level of about 65 tonnes. The Finnish population increased slightly, while the average affluence level increased significantly. Total salmonid consumption increased substantially during the period. The increasing percentage of imported salmonids and improvements in domestic aquaculture technology ended the period of strong growth of emissions in the 1980s. Decreasing the nutrient load through reductions in salmonid consumption in the future is unlikely, due to health benefits and consumer preferences. Replacing domestic production with import of salmonids raises questions regarding outsourcing of the environmental impact, and regarding rural development in Finland. Major improvements in production technology are not in sight. New perspectives on rainbow trout aquaculture may be needed, including using feed from the Baltic Sea, thus closing the nutrient cycle or changing consumption and production to herbivorous fish species.     

Post-smolt migration of Atlantic salmon, Salmo salar L., from the Simojoki river to the Baltic Sea

The migration pattern of Atlantic salmon ( Salmo salar L.) post-smolts in the Baltic Sea was investigated based on tag recoveries of Carlin-tagged wild and hatchery-reared smolts released in the Simojoki river in 1972–2005. Exact date of sea entry was known only for the wild smolts. Tag recoveries of wild salmon in the estuary within 10 km from the river mouth were received on average 3.5 days (±2.0 SD) after release. Time required for emigration from the estuary was dependent on the sea surface temperature (SST) off the river ( R ² = 0.625, P = 0.004), being shorter in years with warmer than colder sea temperatures. Outside the estuary, the wild and hatchery-reared post-smolts migrated southwards along the eastern coast of the northern Gulf of Bothnia, the tag recoveries coinciding with the warm thermal zone in the SST occurring along the coastal area. After arriving in the southern Gulf of Bothnia in late summer the post-smolts mostly migrated near the western coast, reaching the Baltic main basin in late autumn. The relationships between the marine conditions and migration patterns are discussed.     

Fecundity and the survival conditions of the offspring of the Baltic Cod <Emphasis Type="Italic">Gadus morhua callarias</Emphasis> (Gadidae)

The interannual and ontogenetic dynamics of the fecundity of the Baltic cod Gadus morhua callarias and the dependence of the number of the offspring on the reproduction conditions were studied. The absolute individual fecundity and the relative individual fecundity had no pronounced interannual dynamics for the period of 1994?2013. The maximal population fecundity was observed in early 1980, the minimal, in 1990?2000. Nearly every year, the highest contribution to the population fecundity belongs to the 4?5-year old females. The ranking of the survival rates and the year-class strength for the females at the age of 2 years showed that the emergence of the generations of high and average productivity (1980?1986) referred to the unfavorable and moderate survival conditions during the early ontogenesis. During the period of small stock (after 1987), the conditions were mostly favorable and moderate. It is suggested that the significant role in the offspring dynamics belongs to the factors linked to the population density. After 2005, favorable survival conditions promoted the increase of the Baltic cod abundance; this increase was also supported by the decrease of the commercial fishing and by the sporadic large-scale advective processes.