Добірка наукової літератури з теми "Silver perch"

Larval silver perch (Bidyanus bidyanus) and golden perch (Macquaria ambigua) were subjected to gradients of light, depth, flow and wood leachate from river red gum (Eucalyptus camaldulensis) as well as a control treatment with no gradient. Both species were strongly attracted to light, while golden perch larvae were also attracted to river red gum and were carried downstream by water flow. Neither species displayed any response to depth. Gradient responses of silver perch were significantly more variable (P < 0.05) than those of golden perch, which may result in silver perch larvae being more widely distributed in floodplain habitats. Golden perch larvae may be more closely associated with inundated river red gum than silver perch larvae.

Radio tagging and tracking are widely used to study freshwater fish; however, details of fish survival or tag retention rates are rarely reported. The results from five independent tagging trials associated with different tag attachment methods are reported in the present study. Implanted peritoneal cavity tags were trialled for two native Australia freshwater fish species (golden perch and silver perch) and introduced carp. Oesophageal and external tags were also trialled on silver perch. The results from the peritoneal cavity implantation trials in golden perch, silver perch and carp achieved an overall success rate of 81% (after 315 days), 18% (after 200 days) and 43% (after 323 days) respectively. The external attachment of radio tags to silver perch had limited success with all fish either rejecting their tags or dying before 256 days. Silver perch trialled with oesophageal tags had an overall success rate of 25% after 200 days. The trials indicate that internal tagging is suitable for longer-term radio tracking of golden perch, but further developments are required for longer-term applications to silver perch and carp. Tag rejection rates are unlikely to be constant between species or through time and this variability should be incorporated into the study design to prevent bias.

Trials were conducted to evaluate coded wire tags for marking hatchery-produced golden perch and silver perch fingerlings prior to their release into the wild. Two size classes of fish were tagged: 'small' fish were 21-39 mm in total length and 'large' fish were 50-71 mm in total length. Tags were implanted into either the cheek muscle or the snout. Tagging rates were 200-548 fish h-1. Although tag retention in large cheek-tagged golden and silver perch was 100% after 30 days, rearing fish to this size was not practical. Retention rates for small cheek-tagged golden perch (94%) and silver perch (100%), the usual size of fingerlings when released to the wild, were considered to be sufficient for a tagging programme. Retention of tags in the snout was poor; only 6% of golden perch and 48% of silver perch retained tags after 30 days. Most cheek-implanted tags that were shed by fish during long-term tag-retention trials were lost in the first four months. With the exception of silver perch in one trial, which were infested by Ichthyophthirius multtfiliis, survival of tagged fish was 95-100% after 30 days. Factors affecting tag retention and survival of tagged fish, including fish size, tagging site and operator experience, are discussed. The results indicate that coded wire tags are a potential means of marking golden and silver perch fingerlings prior to stocking. Their use will assist fisheries managers in the assessment of the contribution of stocking programmes to commercial and recreational fisheries.

Juvenile silver perch, Bidyanus bidyanus, were subjected to direct transfer from fresh water to various test salinities. No mortality was observed when the fish were transferred from fresh water to a salinity of 12, but 40% mortality was observed at a salinity of 15 after seven days. Pre-acclimation of silver perch to a salinity of 12 for seven days resulted in only marginally better survival at higher salinities. Plasma osmotic concentrations of silver perch rose slightly in salinities below 9 but rapidly at higher salinities, following the same track as the iso-osmotic line. Minimum body water content was observed in individuals subjected to a salinity of 15 for 24 h. As found in other freshwater teleosts, chloride cells were found in the branchial epithelium of silver perch. Accessory cells were observed beside the chloride cells in both freshwater and salt-water conditions. Fish subjected to a salinity of 12 for seven days showed chloride cells with a more developed tubular system than controls. The length of the junctions between chloride cells and accessory cells was significantly shorter in fish adapted to a salinity of 12 than in controls. The ultrastructural feature of 'interdigitations' of accessory cells was not observed during salt-water adaptation. These data indicate that silver perch is the least tolerant of high salinities and the most truly freshwater Australian teleost species examined to date.

Fertilization of earthen ponds used to rear the larvae of golden perch, Macquaria ambigua, and silver perch, Bidyanus bidyanus, resulted in phytoplankton blooms dominated by the cyanobacterium Anabaena possibly because of a low N:P ratio. There was a zooplankton succession of rotifers (mostly Brachionus), Moina, Boeckella and Mesocyclops, and then Daphnia. An increase in Daphnia correlated with a decline in Anabaena, suggesting grazing on that cyanobacterium. Golden perch larvae included copepods in their diet whereas silver perch did not, and this was reflected in lower Boeckella numbers in the golden perch ponds. There was sufficient zooplankton forage, supplemented by chironomid larvae in the later stages of the rearing ponds, for fish growth. The limnological conditions and zooplankton communities in these ponds provide a model for evaluating nursery grounds for these fish.

ABSTRACT Epitheliocystis in leafy seadragon (Phycodurus eques), silver perch (Bidyanus bidyanus), and barramundi (Lates calcarifer), previously associated with chlamydial bacterial infection using ultrastructural analysis, was further investigated by using molecular and immunocytochemical methods. Morphologically, all three species showed epitheliocystis cysts in the gills, and barramundi also showed lymphocystis cysts in the skin. From gill cysts of all three species and from skin cysts of barramundi 16S rRNA gene fragments were amplified by PCR and sequenced, which clustered by phylogenetic analysis together with other chlamydia-like organisms in the order Chlamydiales in a lineage separate from the family Chlamydiaceae. By using in situ RNA hybridization, 16S rRNA Chlamydiales-specific sequences were detected in gill cysts of silver perch and in gill and skin cysts of barramundi. By applying immunocytochemistry, chlamydial antigens (lipopolysaccharide and/or membrane protein) were detected in gill cysts of leafy seadragon and in gill and skin cysts of barramundi, but not in gill cysts of silver perch. In conclusion, this is the first time epitheliocystis agents of leafy seadragon, silver perch and barramundi have been undoubtedly identified as belonging to bacteria of the order Chlamydiales by molecular methods. In addition, the results suggested that lymphocystis cysts, known to be caused by iridovirus infection, could be coinfected with the epitheliocystis agent.

A study was conducted to determine relative success of stocking silver perch (Bidyanus bidyanus) at two different sizes: 35 mm and 50 mm total length. By purposeful manipulation of growth rates of pre-stocked fish it was possible to induce unique markers in scale circulus patterns, thus differentially marking the two size-groups. The scale circulus data were acquired with automated video-digitizing equipment. Both size-classes were stocked into two south-eastern Queensland impoundments. Relative stocking success after two years was quantified by sampling surviving silver perch and using discriminant function analysis to assign individuals to their respective size-at-release groups. Relative survival of fish stocked at 35 mm and at 50 mm was not significantly different in either impoundment. Post-stocking growth rates of 35 mm fish were not compromised due to their smaller size at release. From a management perspective, this suggests that 35 mm is a more cost-effective release size of silver perch than 50 mm. This trial demonstrates the feasibility of using scale circulus patterns to differentially mark multiple groups of fingerlings for such controlled experiments.

The ability of silver perch, Bidyanus bidyanus, to digest, tolerate and utilise dietary carbohydrate as an energy source to spare protein was investigated. A series of in vivo digestibility experiments was carried out to assess the ability of silver perch to digest dietary carbohydrate. Results indicated that wheat starch was digested more efficiently than maize starch, pea starch or potato starch. Cooking increased the energy digestibility of diets containing starch. Both the degree of gelatinisation (80>50>25=0%) and inclusion content (30>60%) influenced the digestibility of wheat starch. Protein digestibilities of diets containing up to 60% starch were unaffected. A reduction in the complexity of wheat starch also influenced carbohydrate digestibility. Carbohydrate digestibilities were ranked as follows: Dextrin = gelatinised starch= maltose= glucose >raw starch. The addition ofNatustarch® at a rate of 50 mg kg dief1 increased the digestibility of raw wheat starch, however, the digestibility of gelatinised wheat starch, which was already higher than enzyme treated raw starch, was not improved. The addition of Natugrain-blencl® (j3-glucanase and 13- xylanase, specific to non-starch polysaccharides [NSPs]) at up 1o 300 J.LL kg-1 to diets containing 30% wheat or de-hulled lupins had no effect on energy or protein digestibility of the diets or ingredients. Silver perch digest the energy from wheat more efficiently than from de-hulled lupins. Silver perch lack the ability to digest energy from NSPs. Intra-peritoneal carbohydrate tolerance tests were carried out to assess the ability of silver perch to utilise the predominant monosaccharides (glucose, galactose and xylose) in plant ingredients currently being used in the fonnulation of aquaculture 11 feeds for this species. When injected with a dose rate of 0.1 g carbohydrate kg body weighf1 , silver perch were glucose tolerant, and galactose and xylose intolerant. Glucose tolerance was progressively compromised with increasing dose rate of glucose.

An energetics model was constructed as an alternative method to length frequency analysis for the estimation of growth for juvenile silver perch, Bairdiella chrysoura. The model approach was adopted since estimation of juvenile estuarine fish growth by only collecting length or weight frequency data is difficult due to the large bodies of water and variety of microhabitats that must be regularly sampled over short time intervals. Field and laboratory data was included in analysis of model compartments for growth, metabolism, food intake and energy loss in waste products. Food habit studies indicated that silver perch is a planktivore that feeds on calanoid copepods during the day and mysids at night. Estimated energy utilization for silver perch at maintenance and maximum rations were similar to literature values for yellow perch, Perca flavescens, and brown trout, Salmo trutta. Model simulation of growth for silver perch in the York River, Virginia from July through October 1981, contained less variation in the size prediction than growth rates determined by length frequency analysis. The model did not contain periods of negative growth as did the field data. By the end of the season, model predictions of silver perch length matched the average length of silver perch captured in the lower York River. The construction of energy utilization models through complementary laboratory and field research has been demonstrated to be a viable method for estimating growth for juvenile fishes. Length frequency analysis is limited to only expressing growth over time. The advantages of an energetics model are that it also defines trophic and ecological interactions as well as environmental factors that impact growth.

This research investigated a number of issues regarding hepatitis B virus (HBV) in the silvery gibbon (Hylobates moloch). Due to the relatively recent discovery of the virus in nonhuman primate populations, specific knowledge of the biological behaviour of the virus is presently lacking, with current information largely extrapolated from the behaviour of HBV in human infections. In order to manage the captive and wild populations of this critically endangered species, information regarding the behaviour of the virus in gibbons and the likely impact of the viral infection is essential. The research was performed at Perth Zoo, with the study population consisting of the current and historical members of the zoo’s silvery gibbon colony. Because this gibbon species is critically endangered, the study was conducted with minimal intervention to the population with samples collected largely on an opportunistic basis from a small study population. Review of the history of the virus within the Perth Zoo colony provided epidemiological evidence to indicate vertical transmission in three gibbons (Hecla, Uban and Jury). It would appear that vertical transmission is the primary mode of transmission leading to dispersal of the virus through the captive population of silvery gibbons. Elevated concentrations of the liver enzymes alanine aminotransferase and aspartate aminotransferase were found in three gibbons (Perth 2, Uban and Jury), and may suggest a pathogenic role of the virus in this species. Histological examination of the livers of Uban and Perth 2 failed to demonstrate definitive evidence of cirrhosis, however mild fibrosis was seen in both cases and may represent an early stage of liver pathology associated with chronic hepatitis B infection. The vaccination protocol developed at Perth Zoo was successful in preventing neonatal transmission of the virus from a high infectivity carrier mother in at least two individuals, and was also successful in producing a protective level of immunity against the virus in all three of the individuals tested. Sequencing of the complete hepatitis B genome from one gibbon (Hecla) revealed that she was infected with GiHV (Gibbon hepatitis B virus), an indigenous strain of HBV previously identified in a number of gibbon species, but not previously confirmed in the silvery gibbon. Hecla's strain of HBV was shown to be more closely related to other nonhuman primate strains of HBV than to any of the human strains of HBV. 100% nucleotide similarity to two of Hecla’s siblings indicates that infection in all three animals was the result of vertical transmission from their mother. Partial sequencing of the virus from a second gibbon (Uban) identified another strain of GiHBV which supports the results of the epidemiological study. Neither gibbon showed a high sequence similarity to the virus sequenced from Ivan, the father of the third carrier gibbon (Jury), although only limited sequence data was available from Ivan. Consequently it is likely that at least three different strains of GiHBV are present within the silvery gibbon population. The information contained in this thesis will assist in the understanding and management of hepatitis B infection in silvery gibbons, as well as the numerous other species of nonhuman primates now shown to be susceptible to this virus.

碩士
國立成功大學
高階管理碩士在職專班(EMBA)
102
Fish meal is the main raw material of protein in feed, however, as the lacking source of the ocean, the cost share is more and more. Meat meal is the other one protein source , but BSE causes concerned issue in feed using. How to find the alternative protein is the most issue in feed. Soy source of vegetal protein is the choice, which with high protein content and balanced amino acid composition. Aquaculture in Taiwan, the feed costs share about 70 %, staff costs share about 2 %, electric bill, water bill and fish medication share about 1 % for Silver perch feed. Under the rising cost of fish meal, vegetal protein price is relative cheaper, only weight gain, and feed conversion rate is not affected and accepted. Vegetal protein is definitely to replace fishmeal for cost down purpose.

Problems caused by multidrug resistant bacteria and the limited number of control strategies, highlight the need for alternative control approaches against bacterial infections in the aquaculture sector. Bacteriophages (phages) demonstrated promising results as therapeutic tools, for the effective control of bacterial diseases in aquaculture, as well as in other production animals, companion animals and humans. In the present study, a range of investigations were undertaken to assess suitability of using lytic phages in controlling Aeromonas hydrophila infection in fish aquaculture. A. hydrophila is a fish pathogen and responsible for economic damages to the aquaculture industry. The main focus of this study was to develop and use a suitable model to test the efficacy of a phage therapy by addressing the concerns associated with the potential limitations of the therapy, such as required doses and delivery methods, characterisation at the genomic level, storage methods, and the phage therapy effect, potential immune response, and effects on fish in response to multiple phage treatments. For the isolation of suitable A. hydrophila phages, wastewater was used as a source and ten different A. hydrophila strains were used as hosts to culture and screen potential phages with lytic ability. Before use in isolation, the bacterial strains were confirmed for any prophage induction using Mitomycin C assay. The water samples were filtered to retain only virus particles and enriched with A. hydrophila strains, filtered again to remove the bacterial hosts and then subjected to a series of plaque assays to screen potential lytic phages. The morphology of the isolated phages was characterised by Transmission Electron Microscopy (TEM); genetic organisation was determined by enzymatic digestions of their nucleic acids and lytic ability was determined by growth pattern while growing with their respective host bacteria. Four selected phages were subjected to whole genome sequencing using Illumina technologies with a view to determining their phylogeny, adaptive evolution, biodiversity, potential virulence and presence of any toxin genes. The isolated and selected phages were then subjected to a study to determine their shelf lives under long-term storage conditions as a solution and in a freeze-dried form. To store as a solution, effect of different concentrations of sucrose and trehalose on the bacteriophage titre were compared with no sugar treatments under 4 °C, -20 °C and -80 °C for 56 weeks. To store in a lyophilised form, bacteriophage solutions were prepared with and without sugars (sucrose and trehalose) and then freeze dried and stored at 4 ℃ and room temperature for 44 weeks. For both trials, bacteriophage titre was monitored weekly for first 8 weeks and then monthly until the end of the experiments. Any changes in phage morphology after lyophilisation was determined by TEM. The therapeutic potential of isolated phages was assessed in fish trials with a native Australian fish, silver perch (Bidyanus bidyanus) against one strain of A. hydrophila. A cocktail of four selected phages was prepared. Different phage doses were determined based on different phage titres to be tested on live fish models infected with A. hydrophila to understand the effects of environmental conditions and dose response of the therapeutic mode. The fish infection trial was conducted in two different phases – preliminary pilot trial and actual infection challenge trial. The preliminary pilot trial utilised 15 fish intraperitoneal injected with different quantities of A. hydrophila and a control group with phosphate buffered saline (PBS). After 6 days, the infected fish were euthanized and organs were collected for bacterial load determination. In the actual infection challenge trial, 144 fish were employed in three groups – control (no treatment, only PBS); A. hydrophila infected fish treated with different doses of bacteriophage cocktails; and uninfected fish treated with different doses of bacteriophage cocktails. At the end of the trial, bacterial load was counted from spleen and kidney and histopathology conducted on various fish organs. Fish blood was analysed for presence/absence of A. hydrophila and to determine lysozyme activity and IgG levels as indicators of immunological response to bacteria or the bacteriophage. Screening for potential A. hydrophila phages with lytic ability resulted in the selection of four phages, coded as Ah6_G, Ah9_PP, Ah10_Se and Ah10_S. The isolated phages demonstrated complete lysis against their respective hosts and contained non-contractile tails with icosahedral heads belonging to Siphoviridae family (Ah6_G, Ah10_Se and Ah10_S), and icosahedral heads with short tail belonging to Podoviridae family (Ah9_PP). All the isolated phages contained dsDNA of > 10 Kb as their genetic materials. The whole genome analysis revealed that all these four phages are closely related to Ahp1 podovirus in terms of their genetic similarity. The whole genome sequencing of the selected phages confirmed that all the isolates contained typical phage protein coding genes, ds DNA and smaller sizes of genomes of Ah6_G (circular), Ah10_Se (linear) and Ah10_S (linear) (47-61 Kb) than other Siphoviridae phages, However, size of the genome of Ah9_PP (41 Kb, circular) was similar to other Podoviridae phages. Two of the phages (Ah10_Se and Ah10_S) were identified as novel linear dsDNA phages with protein coding sequences having no similarities found in the existing phage databases. The phage shelf life study revealed that solutions of the four isolated phages could be preserved without any sugar stabilizers for 56 weeks at both 4 ℃ and -80 ℃ with no significant reduction in their titre. However, -20 ℃ was found to be less effective temperature in maintaining shelf lives of phages Ah6_G and Ah9_PP. Interestingly, the shelf life of these two phages at -20 ℃ were significantly improved when sucrose or trehalose added, sucrose being the better protectant. Nevertheless, the sugars did not have any adverse effects on their shelf lives over the experimental periods. When lyophilised, a small reduction in titre of Ah10_Se and Ah10_S was observed which was improved by adding sucrose and trehalose. Exclusion of sugars during lyophilisation caused disruption of heads and tails of the viruses. In the presence of sucrose or trehalose, the lyophilised phages were more stable when stored at 4 °C compared to room temperature. Nontheless, the presence of sucrose or trehalose provided better stability to the lyophilised phages at either temperatures. However, storing the phages in solution was proved to be better than lyophilisation over the experimental periods. In the fish trial to assess therapeutic potential of isolated phages, a phage cocktail was used to treat A. hydrophila infections in silver perch fish model. Unfortunately, when purchased the fish had already been exposed to A. hydrophila. A medium dose of phage cocktail significantly reduced the background A. hydrophila count in the kidney and spleen of the fish group that did not receive intraperitoneal bacterial inoculation. When the fish were deliberately infected with exogenous A. hydrophila on top of the existing colonisation with Aeromonas sp., there were no significant differences in bacterial counts when challenged with any of the doses of phages. No significant immune response was observed during the challenge trial. The comparative histopathology study of different tissues of the experimental fish revealed very few significant changes that are consistently associated with A. hydrophila infection in teleost fish. This thesis provides new information on the properties of phages able to kill A. hydrophila and that have potential for use as treatments in controlling A. hydrophila infection in fish. Further studies are required to conduct larger scale fish trials involving different species of fish to expand, validate and implement the knowledge and approaches generated in this study.
Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 2022

The silver perch, Bidyanus bidyanus is an Australian native fish of great aquaculture potential. Currently, silver perch represent a major freshwater aquaculture industry in Australia. There have been some research on the biology and nutrition of silver perch but until now there has been no research on the quality and quantity of wastes that may result from aquaculture of silver perch or other species in Australia. The present study was undertaken primarily to investigate the biological growth of silver perch juveniles fed on artificial and sewage grown zooplankton, and quantifies solid and nutrient load from rearing of silver perch at different temperatures. The present study demonstrated that silver perch can grow significantly faster at a temperature close to it's optimum. It also show that sewage grown zooplankton was an inexpensive and alternative diet in the rearing of silver perch juveniles. The study reveals that culture of fish at their optimum temperature may enhance nutrient retention and a reduction in the discharge of nutrient to the environment. The study further indicated that rearing of silver perch in a slightly saline conditions may be another option for achieving better growth rates and provide a lower nutrient loading to the environment.

博士
國立中興大學
生物產業機電工程學系所
103
Abstract The primary objective of this study was to develop an adaptive neural-based fuzzy inference system (ANFIS) for feeding decision-making in aquaculture. Silver perch (Bidyanus bidyanus) were raised under semi-intensive conditions in Taiwan. Because dissolved oxygen (DO) is a key factor that is helpful in detecting the appetite of fish at the initial period of the feeding activity and because the flocking and struggle behaviors of food-searching fish have a transient effect on the measurement of the DO, a simple water-reused rearing tank was prepared to measure the DO to develop an intelligent feeding decision control system. The experimental results demonstrated that the value of the dissolved oxygen increased continuously and rapidly during the feeding process, so that the change rate of dissolved oxygen in 80 seconds and the maximum change of dissolved oxygen in 4 minutes were first applied to find the characteristic parameters that have relation with the bass`s searching behaviors. A three-layer back-propagation artificial neural network was utilized to establish a feeding recognition system for aquaculture. The two characteristic factors were used as the input parameters of this neural network. In order to find the best model for recognition, the type and number of the training sample, the nodes of the hidden layer were changed during the training process. The tests show the feeding decision made by the neural network approach, with an accuracy of 96.1%, is close to actual searching behaviors. In the equivalent ANFIS of the fuzzy logic controller (FLC), two linguistic variables were used to describe the food-searching state of the fish population and establish a rule base composed of 15 rules. Furthermore, an alternate hybrid learning approach, which is a fuzzy logic technique based on artificial neural networks, was suggested to quickly model the linguistic variables and evaluate their relative contributions. The results indicated that a decision threshold of 0.17, which was inferred using the fuzzy logic approach, considerably benefits the feeding decision; the high rate of accurate judgments (with an accuracy of 97.89% for training data and 100% for predicting data), which was obtained by the ANFIS model, was close to the actual food searching behaviors of fish. Therefore, the application of the ANFIS model to the feeding decision system in an aquaculture rearing tank has considerable potential for success.

The intensive aquaculture of silver perch in Western Australia is constrained by the lack of control on the broodstock sex and a detailed biological information on the early larval stages. Five experiments were performed to study the reproductive biology of the species, the sex reversals and the feeding biology of the early life of larvae. The result showed that the domestication of the broodstock and the sex reversal are viable options with hormonal feed supplementations.

碩士
臺灣大學
漁業科學研究所
98
Abstract Silver perch, Bidyanus bidyanus, and Jade perch, Scortum barcoo, are the native species in Murry-Darling and Barcoo river system, Australia, and freshwater finfish with euryhaline, eurytheraml , omnivorous, and high feed conversion ratio. Regard as having a high potential for aquaculture in Taiwan. The experiment designed fish meal level and recombinant tilapia insulin growth factor type I and type II (IGF-I and IGF-II) to investigate the growth performance of juvenile silver perch and jade perch. Setting for 9 groups in the experiment, FM60 group supplement with 60% fish meal, FM30 group supplement with 30% fish meal, 20% corn germ meal and 23% corn protein, FM0 group supplement with 0% fish meal, 3% blood meal and feather meal , 10% corn germ meal and 51% corn protein. Moreover, supplement with 0.5g/100g recombinant tilapia insulin growth factor type I and 0.018g/100g type II (IGF-I and IGF-II) to experiment groups, respectively. Exp 1st results: After 56 days feeding trial, supplement with IGF-I, results for the FM30-eI0.5 has the best performance with percent weight gain 166%, feeding efficiency 45%. In the experiment, FM30 group growth performance is better than non-supplement with IGFs and supplement with IGF-I between IGF-II is no significant difference (p&lt;0.05). Exp 2nd results: After 42 days feeding trial, FM30-eI0.5 has the best performance with percent weight gain 206%, feeding efficiency 64% , and with significant difference results between other groups (p&lt;0.05). The FM30 group growth performance is better than FM60 group and FM0 group, and supplement with IGF-I growth performance is better than IGF-II.

Schule ist ein zentraler Ort für die Prävention sexualisierter Gewalt und die Vermittlung Sexueller Bildung. Das BMBF-Forschungsprojekt »SeBiLe – Sexuelle Bildung für das Lehramt« hat jedoch gezeigt, dass Lehrkräfte in Deutschland in beiden Bereichen nicht ausreichend aus- und fortgebildet werden. Die Herausgeberinnen präsentieren die Ergebnisse der dreijährigen empirischen Forschung des Projekts SeBiLe und betten sie mithilfe der Beitragenden in den fachspezifischen Diskurs ein. Kernstück des Bandes ist ein daraus entwickeltes praxisorientiertes Curriculum, das Anregung zur Umsetzung konkreter Inhalte in der Lehramtsaus- und fortbildung bietet. So ermöglichen die Autor:innen einen direkten Transfer der im Projekt gewonnenen Erkenntnisse in die Aus- und Fortbildung von Lehramtsstudierenden und Lehrer:innen und zeigen verbliebene Handlungsbedarfe in Forschung und Praxis auf. Mit Beiträgen von C. Bergmann, S. Berndt, A. de Silva, B. Drinck, H. Holz, N. Kallweit, J. Keitel, C. Khamis, B. Kollinger, E. Kubitza, L. Lache, S. Maschke, A. Meyer, H. Paech, D. Pech, B. Proll, P. Scheibelhofer, A. Schmidt, J.K.M. Siemoneit, T. Simon, L. Stecher, J.W. Stein, M. Urban, H.-J. Voß, A. Weist, S. Wienholz und D. Zimmermann.

In the Serbian fishing industry, carp breeding in pond is the most important activity. Analysis has shown that breeding may be organized in a two-level semi-intensive system, or in a fully intensive breeding system. Carp farms in Serbia cover any area of around 10,000 ha, with an annual restocking of young fish at around 8,600 ha. Species usually bred include carp, bighead carp, silver carp, grass carp, catfish, pike, and perch. By the level of production of edible fish in carp ponds, with an average production level of 5,000-7,000 tons of fish annually, Serbia takes an important place in Europe. In the chapter, the authors calculate several performance indicators of production for all carp farms, and the results show that by the production intensity Serbia is highly positioned in Europe.

<em>Abstract</em>.—We evaluated long-term fisheries data relative to a range of perturbations for the Arkansas River from 1970 to 2006. Rotenone sample sites were located at pool 13 (Garrison Creek), Ozark Lake (Lavaca), and Lake Dardanelle (Panther Cove and the Arkansas Nuclear 1 Effluent Bay). The period of record was 24 years for Garrison Creek and Lavaca, 29 years for Effluent Bay, and 30 years for Panther Cove. Mean total fish biomass ranged between 466 kg/ha and 1,601 kg/ha among sites, and no temporal trends were detected for total biomass. Invasion of zebra mussels <em>Dreissena polymorpha</em>, discovery of largemouth bass virus, and imposition of a 381 mm total length (TL) minimum length limit for largemouth bass <em>Micropterus salmoides </em>likely contributed to notable changes in these fisheries during the past 30 years. Biomass of redear sunfish <em>Lepomis microlophus</em>, freshwater drum <em>Aplodinotus grunniens</em>, and blue catfish <em>Ictalurus furcatus </em>increased in association with the invasion of the river by nonnative zebra mussels. Spotted gar <em>Lepisosteus oculatus </em>and paddlefish <em>Polyodon spathula </em>biomass increased, and common carp <em>Cyprinus carpio </em>biomass declined coincident with the zebra mussel invasion. Large-scale sedimentation of aquatic habitats may have been related to observed declines of backwater-oriented species, especially common carp and spotted gar. The frequency of largemouth bass between 350 and 400 mm TL increased in electrofishing samples after the imposition of a 381-mm-TL minimum length limit, and total catch per hour of largemouth bass greater than 381 mm TL increased. Our associations would suggest that the discovery of largemouth bass virus during 2000 contributed to (1) lower electrofishing catch per hour of largemouth bass greater than 533 mm TL, and (2) an average increase of 420 h required for an angler to catch a 2.27-kg largemouth bass. We anticipate further changes in the Arkansas River during the next decade from the biological invasions of white perch <em>Morone americana</em>, bighead carp <em>Hypophthalmichthys nobilis</em>, and silver carp <em>H. molitrix</em>; increased establishment of aquatic vegetation; and accelerated loss of aquatic habitats associated with planned federal navigation channel improvements.

Abstract The Kalgoorlie gold camp in the Yilgarn craton of Western Australia comprises the supergiant Golden Mile and the smaller Mt. Charlotte, Mt. Percy, and Hidden Secret deposits. Since the camp’s discovery in 1893, ~1,950 metric tons (t) of Au have been produced from a total estimated endowment of ~2,300 t. The camp is located within Neoarchean rocks of the Kalgoorlie terrane, within the Eastern Goldfields superterrane of the eastern Yilgarn craton. Gold mineralization is distributed along an 8- × 2-km, NNW-trending corridor, which corresponds to the Boulder Lefroy-Golden Mile fault system. The host stratigraphic sequence, dated at ca. 2710 to 2660 Ma, comprises lower ultramafic and mafic lava flow rocks, and upper felsic to intermediate volcaniclastic, epiclastic, and lava flow rocks intruded by highly differentiated dolerite sills such as the ca. 2685 Ma Golden Mile Dolerite. Multiple sets of NNW-trending, steeply dipping porphyry dikes intruded this sequence from ca. 2675 to 2640 Ma. From ca. 2685 to 2640 Ma, rocks of the Kalgoorlie gold camp were subjected to multiple deformation increments and metamorphism. Early D1 deformation from ca. 2685 to 2675 Ma generated the Golden Mile fault and F1 folds. Prolonged sinistral transpression from ca. 2675 to 2655 Ma produced overprinting, NNW-trending sets of D2-D3 folds and faults. The last deformation stage (D4; &lt; ca. 2650 Ma) is recorded by N- to NNE-trending, dextral faults which offset earlier structures. The main mineralization type in the Golden Mile comprises Fimiston lodes: steeply dipping, WNW- to NNW-striking, gold- and telluride-bearing carbonate-quartz veins with banded, colloform, and crustiform textures surrounded by sericite-carbonate-quartz-pyrite-telluride alteration zones. These lodes were emplaced during the earlier stages of regional sinistral transpression (D2) as Riedel shear-type structures. During a later stage of regional sinistral transpression (D3), exceptionally high grade Oroya-type mineralization developed as shallowly plunging ore shoots with “Green Leader” quartz-sericite-carbonate-pyrite-telluride alteration typified by vanadium-bearing muscovite. In the Hidden Secret orebody, ~3 km north-northwest of the Golden Mile, lode mineralization is a silver-rich variety characterized by increased abundance of hessite and petzite and decreased abundance of calaverite. At the adjacent Mt. Charlotte deposit, the gold-, silver-, and telluride-bearing lodes become subordinate to the Mt. Charlotte-type stockwork veins. The stockwork veins occur as planar, 2- to 50-cm thick, auriferous quartz-carbonate-sulfide veins that define steeply NW- to SE-dipping and shallowly N-dipping sets broadly coeval with D4 deformation. Despite extensive research, there is no consensus on critical features of ore formation in the camp. Models suggest either (1) distinct periods of mineralization over a protracted, ca. 2.68 to 2.64 Ga orogenic history; or (2) broadly synchronous formation of the different types of mineralization at ca. 2.64 Ga. The nature of fluids, metal sources, and mineralizing processes remain debated, with both metamorphic and magmatic models proposed. There is strong evidence for multiple gold mineralization events over the course of the ca. 2.68 to 2.64 orogenic window, differing in genesis and contributions from either magmatic or metamorphic ore-forming processes. However, reconciling these models with field relationships and available geochemical and geochronological constraints remains difficult and is the subject of ongoing research.

In the Kuchurgan reservoir there are 40 species of fish, of which in the control fish catches of 2007-2017 were recorded 13 commercial species. The most numerous species is the silver crucian - 22% of all fish in the catches, the remaining species occupy from 4.3 to 0.02%, which indicates the imbalance of the commercial herd of fish and the need for measures to improve the ichthyological situation in the reservoir. The accumulation of metals (V, Mo, Pb, Ni, Cd, Zn, Cu) in the organs and tissues of 3 species of fish of the Kuchurgan reservoir (Carassius auratus gibelio, Hypophthalmichthys nobilis Perca fluviatilis) was studied. In the species of fish studied, metals are the least concentrated in the gonads and muscles of the trunk, while their maximum concentrations are mostly noted in the gills and skin, with the exception of copper, which accumulates more in the liver of fish.