Search Results - (Author, Cooperation:N. Metcalfe)
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1Latest Papers from Table of Contents or Articles in PressM. Nicholl ; S. J. Smartt ; A. Jerkstrand ; C. Inserra ; M. McCrum ; R. Kotak ; M. Fraser ; D. Wright ; T. W. Chen ; K. Smith ; D. R. Young ; S. A. Sim ; S. Valenti ; D. A. Howell ; F. Bresolin ; R. P. Kudritzki ; J. L. Tonry ; M. E. Huber ; A. Rest ; A. Pastorello ; L. Tomasella ; E. Cappellaro ; S. Benetti ; S. Mattila ; E. Kankare ; T. Kangas ; G. Leloudas ; J. Sollerman ; F. Taddia ; E. Berger ; R. Chornock ; G. Narayan ; C. W. Stubbs ; R. J. Foley ; R. Lunnan ; A. Soderberg ; N. Sanders ; D. Milisavljevic ; R. Margutti ; R. P. Kirshner ; N. Elias-Rosa ; A. Morales-Garoffolo ; S. Taubenberger ; M. T. Botticella ; S. Gezari ; Y. Urata ; S. Rodney ; A. G. Riess ; D. Scolnic ; W. M. Wood-Vasey ; W. S. Burgett ; K. Chambers ; H. A. Flewelling ; E. A. Magnier ; N. Kaiser ; N. Metcalfe ; J. Morgan ; P. A. Price ; W. Sweeney ; C. Waters
Nature Publishing Group (NPG)
Published 2013Staff ViewPublication Date: 2013-10-18Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsPublished by: -
2Latest Papers from Table of Contents or Articles in PressYoshida, H., Hasegawa, H., Katsuta, N., Maruyama, I., Sirono, S., Minami, M., Asahara, Y., Nishimoto, S., Yamaguchi, Y., Ichinnorov, N., Metcalfe, R.
American Association for the Advancement of Science (AAAS)
Published 2018Staff ViewPublication Date: 2018-12-06Publisher: American Association for the Advancement of Science (AAAS)Electronic ISSN: 2375-2548Topics: Natural Sciences in GeneralPublished by: -
3Articles: DFG German National LicensesMETCALFE, N. ; SHANKS, T. ; ROCHE, N. ; FONG, R.
Oxford, UK : Blackwell Publishing Ltd
Published 1993Staff ViewISSN: 1749-6632Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Natural Sciences in GeneralType of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesSIMPSON, A. L. ; METCALFE, N. B. ; SOAFD, J. E. THORPE
Oxford, UK : Blackwell Publishing Ltd
Published 1992Staff ViewISSN: 1365-2109Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, NutritionNotes: Abstract. Simple body measurements were used to predict the fat content of Atlantic salmon parr. For three different sizes (wet weights 18–98g, 44–207g and 137-151·8g) at two times of year (November/December and July) the percentage body fat (as measured by lipid extraction) could be predicted accurately using multiple regressions based on a combination of the following measurements: wet weight, fork length, opercular height, dorsal height, opercular width, dorsal width, anal width, adipose fin length and condition factor. In every case predictions based on multiple regression equations were more accurate than condition factor alone. This biometric method is easily employed and can potentially be used both in biological studies and on fish farms to assess body condition of individual fish. Since it is non-destructive it has the additional advantage of allowing repeated monitoring of fat levels in the same fish.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1365-2109Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, NutritionNotes: Abstract. It is becoming increasingly clear that cultivated salmon will not perform the way we want them to unless we have a thorough understanding of how the rearing environment will affect their behaviour. This paper illustrates some of the behavioural patterns that can influence feeding and growth rates, and how these may differ between individual fish. A salmon's appetite is not simply a function of temperature: there are complex daily, seasonal and developmental appetite rhythms, which result in some fish becoming anorexic while others continue to feed. The developmental switches which trigger some fish to become anorexic (and so delaying smolting) appear to be irreversible, but individual differences in behaviour in the period leading up to the switch point influence whether fish smolt early or late. Thus more competitive and dominant fish are more likely to become S1 smolts, and these differences in dominance status become established within the first few weeks of feeding. They appear to have a physiological basis: fish with higher metabolic rates (irrespective of initial size) tend to be dominant, and so subsequently grow faster. However, the extent of these behavioural effects will depend on the rearing environment. The challenge is therefore to allow all fish to feed without intimidation, and to devise feeding schedules which take account of complex appetite rhythms — only then will we be working with the fish, rather than against them!Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: A bimodal length distribution developed in an Atlantic salmon population planted as start-fed fry in a Norwegian stream. The earliest fish to smolt were from the upper modal group.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesThe influence of life-history strategy on lipid metabolism in overwintering juvenile Atlantic salmonMorgan, I. J. ; McCarthy, I. D. ; Metcalfe, N. B.
Oxford, UK : Blackwell Publishing Ltd
Published 2002Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: From November to May, the lipid mass in the viscera and carcass of juvenile Atlantic salmon Salmo salar that were undergoing smolt transformation prior to seaward migration (‘early migrants’) were significantly greater than those of their siblings that would delay migration for at least a further year. During winter (November-February), the depletion of lipid associated with the viscera was significantly greater in early migrants, whilst lipid depletion in the remaining carcass was greater in delayed migrants. Early migrants continued to deplete both lipid compartments in spring (February-May), whereas delayed migrants depleted visceral lipid but replenished carcass lipid over the same period. Fatty acid accumulation rates (a measure of storage lipid synthesis rates) were two to six times greater in visceral than in carcass lipid throughout the study, suggesting that lipid turnover is much more rapid in the viscera. There were no differences in fatty acid accumulation rates between migrant groups in November, despite the much lower food consumption rate of delayed migrants at that time, suggesting that these fish allocated a larger proportion of their nutritional resources to lipid synthesis. In the carcass lipid of early migrants, and in both the visceral and carcass lipid of delayed migrants, the fatty acid accumulation rate was negatively correlated with lipid mass. Fatty acid accumulation rates increased from November to February in both visceral and carcass lipid in the two migrant groups. The fatty acid accumulation rate in carcass lipid was significantly higher in delayed migrants than in early migrants in February, but not in May. These results support the hypothesis that life history strategies involving rapid growth will result in a relatively low allocation of resources to lipid reserves.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Juvenile Atlantic salmon Salmo salar subjected to three weeks of cooler temperatures were 8·5% smaller than controls at the end of the temperature manipulation, but had caught up in size 20 weeks later. The behavioural means is examined by which this catch-up or compensatory growth is achieved. While on average compensating fish did not spend more time feeding, dominant fish within each group gained more exclusive access to the feeding area during periods of catch-up growth. Therefore the extent to which compensatory growth could be achieved was dependent on both the social status of the individual and the dominants’ ability to monopolize the food patch.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesCutts, C. J. ; Brembs, B. ; Metcalfe, N. B. ; Taylor, A. C.
Oxford, UK : Blackwell Publishing Ltd
Published 1999Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Three groups of juvenile salmon were introduced sequentially into an artificial stream to investigate the effects of prior residence on behaviour and territory choice. Almost half of the first group obtained and defended distinct territories, the other half being constrained to an area approximately the size of one large territory. All of the fish in the subsequent groups, bar one, were also constrained to the same site. Since the fish were of similar size, prior residence alone seemed to influence which individuals obtained territories. However, within the first group, the fish that obtained territories were larger and more aggressive. The territorial fish did not appear to choose the most profitable territories, although they had the greatest opportunity to do so. Since juvenile salmon emerge from their gravel nests fairly synchronously, a time constraint on site sampling is hypothesised: there may be a risk in taking time to sample sites, since these same sites may become occupied with conspecifics. However, fish with territories fed at faster rates than non-territorial fish, possibly because of reduced competition for prey items. Consequently, fish from the first group (containing most of the territorial fish) grew faster than the other two groups. Moreover, most of the territory holders, but only one of the non-territorial fish, reached the threshold size that increases their probability of smolting the following year. This suggests that ability to obtain a defensible territory, primarily through prior residence, influences the age at which juvenile salmon can migrate to sea.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesHuntingford, F. A. ; Metcalfe, N. B. ; Thorpe, J. E. ; Graham, W. D. ; Adams, C. E.
Oxford, UK : Blackwell Publishing Ltd
Published 1990Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Dominance relationships between pairs of Atlantic salmon parr of known size were assessed at various times during their first year of life. In tests conducted between first feeding and early July, the larger of two fish was dominant in only 54% of pairs, regardless of the magnitude of the size difference between the fish. In September, there was a stronger association between size and status, especially in pairs with a large size differential, where the dominant was larger in 72% of cases. In groups of parr tested in April of the following year, there was no relationship between size and status, the larger of two fish being dominant in 48% of cases, regardless of the magnitude of the size differential. This result suggests that status in early social interactions may depend on behavioural properties rather than size and that the larger size of dominant fish reported in a number of salmonids might be a consequence and not a cause of high status.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesHuntingford, F. A. ; Metcalfe, N. B. ; Thorpe, J. E.
Oxford, UK : Blackwell Publishing Ltd
Published 1988Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: The current speed at which underyearling salmon parr held feeding stations was examined from late summer to early winter in laboratory flume tanks that offered a choice between (a) areas with high water flow, high food availability but high predation risk and (b) areas with low flow, little food but shelter from predators. In August, those fish that would become smolts aged 1 + (and which by late winter formed the upper modal group, UMG, of the bimodal size distribution) adopted positions in faster currents than did the fish which would take a further year to reach the smolt stage (the lower modal group, LMG). However, the chosen current speed of UMG fish decreased through the period of study, so that by December all fish were found in areas of low flow, and hence little food. Both date and water temperature had independent effects on the chosen current speed of UMG fish.The effect of predation risk was investigated using a model trout. A brief sight of this predator caused 47% of fish that had been in the main, exposed currents to move to slacker, sheltered areas; they took 1 h, on average, to return to their previous position. The fish that remained in position upon seeing the predator reduced their rate of tail beating, presumably increasing crypticity. Eventual UMG parr were less likely than were LMG fish to move away upon seeing a predator. The fish moved to faster currents than normal 2–3 h after seeing the predator, possibly compensating for the earlier reduction in feeding rate.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesHuntingford, F. A. ; Metcalfe, N. B. ; Thorpe, J. E.
Oxford, UK : Blackwell Publishing Ltd
Published 1988Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Feeding intensity was measured before (baseline level) and after (disturbed level) brief exposure to a potential predator in groups of 0+ Atlantic salmon, Salmo salar. parr destined to follow either a fast-growth, early-smolting life history (upper modal group or UMG fish) or a slow-growth, late-smolting life history (lower modal group or LMG fish). Feeding intensity decreased following exposure to the predator. While the absolute decrease in feeding intensity is constant regardless of baseline level, the proportionate decrease is negatively related to pre-presentation feeding intensity. Parr that are strongly motivated to feed thus maintain a higher food intake and incur greater risks when foraging in the presence of a predator. No differences in baseline or disturbed feeding intensity of UMG and LMG parr were found up to September of their first year. Previous work has shown that baseline feeding intensities decrease in LMG fish after September but increase in UMG fish. In the present study, these differences were reflected in greater disturbed feeding intensities in UMG fish, but fish destined to follow different life history patterns do not differ in risk-taking, once these differences in baseline feeding motivation have been taken into account.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: The interactions between dominance status, feeding rate and growth in rainbow trout, Salmo gairdneri Richardson, were analyzed using published data on experimental populations. There was a positive correlation between metabolic expenditure and food intake in both dominant and subordinate fish, but dominants obtained a greater intake for a given expenditure than did subordinates. Subordinates that adopted a high–return/high–cost foraging strategy actually expended more energy than they acquired, whereas those that minimized energy expenditure obtained a net energy gain. This led to the surprising finding that the growth rate of subordinates was negatively correlated with food intake.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesBaum, D. ; Laughton, R. ; Armstrong, J. D. ; Metcalfe, N. B.
Oxford, UK; Malden, USA : Blackwell Science Ltd
Published 2005Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Atlantic salmon Salmo salar parr exposed to heated water effluent were larger than parr living upstream of the discharge. There was no effect, however, of temperature on the incidence of male parr maturation, despite the link between growth and maturation found in other studies. Mature parr upstream of the effluent were smaller than mature parr downstream of it, suggesting a higher size threshold for maturation in those parr exposed to the heated water. The small distance between upstream and downstream sampling sites probably precluded genetic differences between the parr, thus implying an environmental influence on the threshold size above which male parr matured.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Juveniles of several species of salmonid become almost exclusively nocturnal in winter. Their diel activity schedule is determined mainly by temperature, with the fish seeking shelter increasingly during the day as the temperature drops. Through controlled laboratory experiments, it is demonstrated that a comparable response is found in another stream-dwelling species, the minnow Phoxinus phoxinus. Daytime observations showed that fish were found hiding in refuges on only 20% of occasions at 13.2° C but on over 75% of occasions at 6.6° C. In contrast, the minnows remained in the water column and used the refuges rarely at night irrespective of water temperature. As a consequence their activity became increasingly nocturnal as temperature dropped. It is suggested that this may be an adaptation to avoid diurnal predators.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: During winter, juvenile Atlantic salmon Salmo salar become nocturnal and seek refuge during the day in the stream bed gravel interstitial spaces. The function of this behaviour is unclear, but two major types of hypothesis have been proposed. One is that the fish are hiding from something (e.g. a predator) and the other is that the fish are seeking shelter from the water current. These hypotheses were tested by examining the selection of juvenile salmon for refuges that offered different degrees of concealment or shelter. The fish clearly preferred refuges that allowed them to hide (i.e. they were dark and opaque) but offered little shelter from the current. Therefore, it can be assumed that the primary function of this nocturnal behaviour during winter is most likely to hide from diurnal predators.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: The effects of light level, developmental pathway, and previous growth history on the foraging attack distances of juvenile Atlantic salmon Salmo salar were examined in circular rearing tanks. Former manipulation of growth rates had no significant influence on distances moved to intercept food items despite the fact that it caused substantial differences in post-treatment growth. Attack distances of fish that were entering a state of overwinter dormancy (lower modal group; LMG) were shorter than those of actively feeding (and growing) fish (upper modal group; UMG). These differences were explained generally by differences in body size between the two groups, suggesting that actual effort per attack was unassociated with growth requirements. Significant differences between growing and non-growing fish in attack distances could contribute to the variation in growth rates through their effect on feeding rates, but were unlikely to have affected energetic costs. This may be due to the fact that attack distances were consistently short throughout the study period as is also evident from the pattern of change between night and daytime. Whereas in the first experiment (daylight v. twilight) fish moved further to reach food during the day, in the second (daylight v. overcast night) nocturnal attack distances matched (LMG fish) or exceeded (UMG fish) diurnal attack distances. Thus diurnal attack distances were probably minimized in the second experiment. These results are interpreted within a framework of overwintering strategies.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Resident juvenile Atlantic salmon responded to a period of winter food restriction by subsequently increasing appetite when food again became available. This hyperphagy contributed to the restoration of an energy deficit (derived from a biometric estimation of body lipid reserves) incurred during the period of food restriction. The extent of this deficit influenced the duration of the hyperphagic response: those fish incurring the greatest fat losses maintained appetite longer than those with a smaller energy deficit. The initial feeding intensity of fish incurring a wide range of fat losses was found to be similar, indicating that fish were regulating the length as opposed to the intensity of the hyperphagic response in order to restore losses. The ecological implications of the results are discussed in relation to juvenile salmon overwintering strategies.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesKadri, S. ; Metcalfe, N. B. ; Huntingford, F. A. ; Thorpe, J. E.
Oxford, UK : Blackwell Publishing Ltd
Published 1997Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Daily feeding patterns of tank-reared Atlantic salmon Salmo salar parr under ambient conditions and their relationship with patterns of aggression were investigated during spring and autumn. A single, early afternoon feeding peak was observed during spring but no consistent pattern emerged from the autumn trial (fish did tend to feed in synchrony, even though the population's feeding pattern varied between days). Aggression was highest at first light during both spring and autumn, reducing thereafter throughout the day. Feeding and aggression were out of phase during spring, with the level of feeding increasing as aggression decreased. It is suggested that the high levels of early morning aggression are associated with re-establishment of the social order that breaks down after a period of darkness; in the spring this may have inhibited feeding.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesKadri, S. ; Metcalfe, N. B. ; Huntingford, F. A. ; Thorpe, J. E.
Oxford, UK : Blackwell Publishing Ltd
Published 1997Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Previous studies of feeding rhythms in post-smolt Atlantic salmon Salmo salar have produced variable results. Therefore, the present study was performed to clarify the source of these differences and to examine size-related variation in daily feeding patterns. A small group of hatchery reared post-smolts was kept in an indoor seawater tank under conditions of constant photoperiod and light intensity, and negligible diurnal variation in water temperature. Feeding responses were monitored by video camera throughout the day. The resultant feeding pattern for the population mirrored an earlier study, with the highest levels of feeding activity in the early morning and late evening. Differences between this and other studies may be due to variation in climate, season or life-history stage. Daily feeding patterns were size-dependent. The largest fish fed at a relatively constant level through the day, medium-sized fish fed in a pattern similar to that described above for the population and small fish fed most at first and last light. These differences were due probably to the effect of competitive interactions upon fish of different sizes.Type of Medium: Electronic ResourceURL: