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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Inorganic chemistry 13 (1974), S. 479-480 
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 8 (1978), S. 0 
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY. Opercular bones from 323 perch from the River Stour were used for age and back-calculated growth determinations. Annuli were formed during May at the beginning of the growth period. Growth was minimal from October to April. Female perch grew faster than males, and the growth rates of both sexes were higher than those observed in most other European waters. Spawning occurred during late April and early May; male gonads began development in August and had attained their maximum weight in September, but the ovaries developed gradually from August until April. Immature perch had an annual cycle of condition with a maximum in June-July and a minimum in December-January. The condition of mature males and females was affected by the gonad cycle. The fecundity of Stour perch is expressed by the formula: log egg number = 2.40 log length (mm) - 1.34.Approximately 25% of males were mature at age I and all were mature at age II, whereas most females did not spawn until age III. Ephemeroptera nymphs and minnow fry constituted the bulk of the diet of 0-group perch; Ephemeroptera nymphs, minnow fry and Corixidae were the most numerous items in I group perch, whereas older perch contained Corixidae and a wider range of fish prey species, although minnows were the most numerous of these.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 24 (1984), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A new method of determining fish numbers in a large river, which involved electrofishing from boats downstream to an AC electrical barrier, produced capture efficiencies for different species ranging from 28 to 82% when successive pairs of catches were combined. Estimates of population density, biomass and production for the 18 species in a 2.538 ha segment of the Pilica River, Poland revealed a decline in total numbers of the fish in species diversity between 1963 and 1980. This is attributed to increased fishing pressure, and to a loss in habitat diversity following the loss of many water mills and associated dams. The total production estimate of 0.85 g m−2 year−1 is low compared with the few published estimates for other large rivers. Roach, dace, chub, gudgeon and bream were the most numerous fish and they constituted 75% of the total population estimate, and 68% of the standing crop and annual production.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 1 (1969), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 21 (1989), S. 0 
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY. .1. Chalkstream trout are fast-growing, short-lived with a stable age structure that is a consequence of the lack of extremes in the abiotic environment, especially of water temperature and flow.2. Levels of secondary (invertebrate) production arc high and there is no evidence that interspecific or intraspecific competition for food resources limits growth.3. Dietary studies show a broad similarity between trout and other species, but indicate differences that reflect variations in the micro-habitat distributions between fish species.4. Trout numbers appear to be limited initially by the availability of gravel spawning areas, and then by areas suitable for newly-emerged fry. Reduction in stream discharge in the spring, either naturally or by man, can lower the number of 0+ trout that survive.5. Eels are not important predators on trout eggs or fry. but a reduction in pike numbers can lead to a decrease in the mean weight of pike. Small pike do not pose a serious threat to stocked yearling trout.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 8 (1977), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 21 (1990), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. River Frome pike, Esox lucius L., usually spawned in drainage channels connected to the main river. Most 0+ pike moved into the river during their first summer, but some remained in the channels until the following year. The latter group ate macro-invertebrates (chiefly Asellus), whereas their siblings in the main river were piscivorous. 0+ pike in the channels had slower growth rates than those in the river, but growth rates of the two groups in later years were similar. The presence of these initially slow-growing pike in the population caused problems in identifying the first annulus on the scales. The problem was identified by batch-marking 0+ fish in different years and examining scales from individuals that were subsequently recaptured. The interpretation of true annuli and false checks in older fish was aided by collecting sets of scales from individually tagged pike which were recaptured at intervals over a number of years. The study emphasized the importance of validating age determinations by obtaining information from more than one source.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 11 (1980), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: A simplified Seaburg sampler was used to obtain stomach contents from anaesthetized pike. Well-digested remains of fish prey were identified from pharyngeal bones (Cyprinidae) or the skeletal structure of the caudal region, by comparison with type material collected from fresh fish. The original lengths of the prey were estimated from linear relationships between fish length and size of the caudal fin, or size of the pharyngeal bone. Estimation of prey size from scales or otoliths using length-for-age data gave only approximate values.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 8 (1977), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Routine statistics have been analysed from a varied selection of 18 British reservoir fisheries The numbers and weights of fish caught have been compared with the numbers and weights stocked.In lowland reservoirs the “put and take” system of management is used and annual stocking rates of 40–60 fish ha-1 (c 12 kg ha-1) give catches of 20–30 fish ha-1 (c 20 kg ha-1). Higher stocking rates lead to greater catches numerically but to relatively little increase in the weight of catch per unit area. In general, the recapture of rainbow trout is greater than that of brown trout, relative to the numbers stocked.The management of upland reservoirs is complicated by the presence of indigenous trout, poorer growing conditions and lack of research into the population dynamics of fish populations in such places. A wide variety of management possibilities exist in upland reservoirs and these are worthy of thorough investigation. Stocking at rates comparable to those used in lowland reservoirs takes negligible advantage of the potential for natural trout growth in upland reservoirs and the economics of this practice would repay closer analysis.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 5 (1973), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Scales and opercular bones from 632 roach from the River Stour were used for age and back-calculated growth determinations. The scales had clearer inner annuli but operculars clearer outer annuli in fish more than nine years old. The annuli were laid in late May or early June at the beginning of the growth period. Growth was minimal between November and April. Roach from both rivers grow faster than those in most other European waters. Female roach grow faster than males; River Frome roach faster than those from the Stour. Spawning occurred in May and elaboration of gonads between September and May. Immature roach have an annual cycle in condition with a maximum in June and a minimum in early Spring. The condition of mature females is affected by the gonad cycle. The fecundity of Stour roach is represented by the formula: log egg number=4.43 log length (mm)—1.69. Approximately half of the Stour males attained sexual maturity at age III and most of the rest by age IV. Half of the females were mature at age IV and the remainder by age V. Both brood success and growth rate varied from year to year but independently of one another. Most Stour roach ate aquatic insect larvae and molluscs but algae were more frequent in the diet of larger fish.
    Type of Medium: Electronic Resource
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