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Teichert MAK, Kvingedal E, Forseth T, Ugedal O, Finstad AG. Effects of discharge and local density on the growth of juvenile Atlantic salmon Salmo salar. JOURNAL OF FISH BIOLOGY 2010; 76:1751-1769. [PMID: 20557629 DOI: 10.1111/j.1095-8649.2010.02614.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The study explored the combined effects of density, physical habitat and different discharge levels on the growth of juvenile Atlantic salmon Salmo salar in artificial streams, by manipulating flow during both summer and winter conditions. Growth was high during all four summer trials and increased linearly with discharge and mean velocity. Differences in fish densities (fish m(-3)) due to differences in stream volume explained a similar proportion of the variation in mean growth among discharge treatments. Within streams, the fish aggregated in areas of larger sediment size, where shelters were probably abundant, while growth decreased with increasing densities. Fish appeared to favour the availability of shelter over maximization of growth. Mean growth was negative during all winter trials and did not vary among discharge treatments. These results suggest that increased fish densities are a major cause of reduced summer growth at low discharge, and that habitat-mediated density differences explain the majority of the growth variation across habitat conditions both during summer and winter.
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Affiliation(s)
- M A K Teichert
- Norwegian Institute for Nature Research, Tungasletta 2, N-7485 Trondheim, Norway.
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52
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Leduc AO, Kim JW, Macnaughton CJ, Brown GE. Sensory complement model helps to predict diel alarm response patterns in juvenile Atlantic salmon (Salmo salar) under natural conditions. CAN J ZOOL 2010. [DOI: 10.1139/z10-016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fish rely on both chemical and visual cues to evaluate predation risk. Decisions with respect to activity partitioning in time (i.e., night vs. day) rely on accurate assessment of predation risk relative to energy intake; predation risk is generally thought to be lower at night at the expense of feeding opportunities. At night, the sensory complement model predicts greater reliance on chemical perception of risk. Under this condition, a lower ability to use vision should result in a more conservative response to chemical cues than during the day. We tested this hypothesis under natural conditions by comparing the alarm response of young-of-the-year Atlantic salmon ( Salmo salar L., 1758) under summer day and night conditions in salmon nursery streams. We found that salmon responded to the alarm cues to a significantly greater extent at night. This suggests that the sensory complement model may be correct and that nocturnal perception of risk may be generally higher than previously believed for juvenile salmon in the wild. In the absence of a more precise indicator of risk (e.g., vision), a greater reliance on chemosensory risk assessment at night may cause fish to shift to more risk-adverse behaviour.
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Affiliation(s)
- Antoine O.H.C. Leduc
- Aquatic Ecology Research Laboratories, The University of British Columbia, 2201 Main Mall, Vancouver, BC V6J 2J2, Canada
- Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, QC H4B 1R6, Canada
| | - Jae-Woo Kim
- Aquatic Ecology Research Laboratories, The University of British Columbia, 2201 Main Mall, Vancouver, BC V6J 2J2, Canada
- Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, QC H4B 1R6, Canada
| | - Camille J. Macnaughton
- Aquatic Ecology Research Laboratories, The University of British Columbia, 2201 Main Mall, Vancouver, BC V6J 2J2, Canada
- Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, QC H4B 1R6, Canada
| | - Grant E. Brown
- Aquatic Ecology Research Laboratories, The University of British Columbia, 2201 Main Mall, Vancouver, BC V6J 2J2, Canada
- Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montréal, QC H4B 1R6, Canada
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Sundt-Hansen L, Neregård L, Einum S, Höjesjö J, Björnsson BT, Hindar K, Økland F, Johnsson JI. Growth enhanced brown trout show increased movement activity in the wild. Funct Ecol 2009. [DOI: 10.1111/j.1365-2435.2008.01532.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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54
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Berg OK, Finstad AG, Solem Ø, Ugedal O, Forseth T, Niemelä E, Arnekleiv JV, Lohrmann A, Naesje TF. Pre-winter lipid stores in young-of-year Atlantic salmon along a north-south gradient. JOURNAL OF FISH BIOLOGY 2009; 74:1383-1393. [PMID: 20735641 DOI: 10.1111/j.1095-8649.2009.02193.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The pre-winter lipid stores of young-of-the-year (YOY, age 0 year) Atlantic salmon Salmo salar were analysed along a north-south gradient from c. 71 to 58 degrees N, with winter conditions ranging from >200 days of ice cover to no ice. The rivers sampled in Northern Norway represent some of the most northerly S. salar rivers. There was an increase in lipid content with increasing latitude, and mean lipid content (size adjusted to common mass) for YOY in northern rivers were almost three times higher: 0.035 g compared to 0.013 g in southern rivers. The relationship was not sensitive to variation in sampling time or variation in YOY body size. The lipid stores, however, varied markedly between rivers and also between neighbouring rivers, indicating different strategies or opportunities for pre-winter lipid storage both at latitudinal and local scales.
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Affiliation(s)
- O K Berg
- Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.
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55
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Kulísková P, Horký P, Slavík O, Jones JI. Factors influencing movement behaviour and home range size in ide Leuciscus idus. JOURNAL OF FISH BIOLOGY 2009; 74:1269-1279. [PMID: 20735630 DOI: 10.1111/j.1095-8649.2009.02198.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Seventeen individuals of ide Leuciscus idus were radio-tracked weekly from September 2003 to September 2004 in the River Elbe, Czech Republic, to examine migration patterns and the influence of environmental factors on their diurnal behaviour. Of the 10 environmental factors measured, L. idus were significantly influenced by turbidity, which increased diurnal movement and the home range size of the species. The peak of longitudinal movement occurred in the spring, indicating pre-spawning migration. Migrating fish moved downstream and later returned upstream to the vicinity of their original locations, displaying a homing behaviour.
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Affiliation(s)
- P Kulísková
- TGM-Water Research Institute, Podbabská 30, Prague 6, Czech Republic.
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56
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DI STEFANO JULIAN, YORK ALAN, SWAN MATTHEW, GREENFIELD ANDREW, COULSON GRAEME. Habitat selection by the swamp wallaby (Wallabia bicolor) in relation to diel period, food and shelter. AUSTRAL ECOL 2009. [DOI: 10.1111/j.1442-9993.2008.01890.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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57
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Pizzatto L, Child T, Shine R. Why be diurnal? Shifts in activity time enable young cane toads to evade cannibalistic conspecifics. Behav Ecol 2008. [DOI: 10.1093/beheco/arn060] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Berger D, Gotthard K. Time stress, predation risk and diurnal–nocturnal foraging trade-offs in larval prey. Behav Ecol Sociobiol 2008. [DOI: 10.1007/s00265-008-0594-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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60
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Cover MR, May CL, Dietrich WE, Resh VH. Quantitative linkages among sediment supply, streambed fine sediment, and benthic macroinvertebrates in northern California streams. ACTA ACUST UNITED AC 2008. [DOI: 10.1899/07-032.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Matthew R. Cover
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720 USA
| | - Christine L. May
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720 USA
| | - William E. Dietrich
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720 USA
| | - Vincent H. Resh
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720 USA
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61
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Cucherousset J, Marty P, Pelozuelo L, Roussel JM. Portable PIT detector as a new tool for non-disruptively locating individually tagged amphibians in the field: a case study with Pyrenean brook salamanders (Calotriton asper). WILDLIFE RESEARCH 2008. [DOI: 10.1071/wr08074] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Passive Integrated Transponder (PIT) telemetry has recently been adapted for locating PIT-tagged fish in shallow waters using portable detectors. In the present study, we tested this method for adult amphibians (Pyrenean brook salamanders, Calotriton asper) PIT-tagged with 12-mm transponders in a headwater rocky stream. PIT telemetry performances were compared with a conventional hand-capture method, i.e. visual searching and overturning movable stones in the streambed. The mean efficiency of the portable detector (88.2% ± 5.2, s.e.) was significantly higher than hand-capture (51.1% ± 6.4) and the operator progressed, on average, four times faster. Time efficiencies were, on average, 0.92 (±0.15) and 0.12 (±0.04) adult salamanders per minute with the portable detector and by hand-capture, respectively. The efficiency of the portable detector was negatively correlated with the percentage of large stones on the streambed. The time needed to prospect a section was positively correlated with the abundance of PIT-tagged adult salamanders, spring inlets and undercut banks. Because PIT telemetry is less disruptive than hand-capture for both salamanders and their habitat, it is a promising and non-disruptive method for developing studies on the ecology and management of amphibians in shallow waters.
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62
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Blanchet S, Bernatchez L, Dodson JJ. Behavioural and Growth Responses of a Territorial Fish (Atlantic Salmon, Salmo salar, L.) to Multiple Predatory Cues. Ethology 2007. [DOI: 10.1111/j.1439-0310.2007.01410.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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63
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Schulz UH, Leuchtenberger C. Activity patterns of South American silver catfish (Rhamdia quelen). BRAZ J BIOL 2006; 66:565-74. [PMID: 16862313 DOI: 10.1590/s1519-69842006000300024] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Accepted: 02/22/2005] [Indexed: 11/22/2022] Open
Abstract
The South American silver catfish (Rhamdia quelen) is a widely distributed species in Central and South America in areas east of the Andes between Venezuela and the northern parts of Argentina. The bottom dwelling species occurs in lakes and reservoirs as well as in rivers. Between June 2000 and December 2001, sixteen silver catfish were tracked during fourteen 24-h cycles in two-hour-intervals, with the aim of investigating daily movements and habitat use. Covered distances varied between 0 m/2 h and 326 m/2 h and the mean distance covered in 2 h was 25.6 m. The mean activity of individual silver catfish varied between 5.6 m/2 h and 81.4 m/2 h. The swimming activity was linearly related to the total fish length. The highest mean swimming activity occurred in the morning and at nightfall. Silver catfish concentrated in three areas of frequent use. All of them were characterized by steep banks providing shelter in the form of rip-rap or large woody debris. Vertically, silver catfish preferred the upper 2 m layer where tracked fish encountered higher temperatures and higher dissolved oxygen concentrations.
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Affiliation(s)
- U H Schulz
- Laboratory of Fish Ecology C2, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-000, Brazil.
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65
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Orpwood JE, Griffiths SW, Armstrong JD. Effects of food availability on temporal activity patterns and growth of Atlantic salmon. J Anim Ecol 2006; 75:677-85. [PMID: 16689950 DOI: 10.1111/j.1365-2656.2006.01088.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1. Patterns of sheltering and activity are of fundamental importance in the ecology of animals and in determining interactions among predators and prey. Balancing decreased mortality risk when sheltering with increased feeding rate when exposed is believed to be a key determinant of diel patterns of sheltering in many animals. 2. Despite lower foraging efficiency at night than during the day, Atlantic salmon Salmo salar parr are nocturnal during winter and at low summer temperatures. Nocturnal activity also occurs at warm water temperatures during summer, but little is known about the functional significance of this behaviour. 3. This study aimed to determine: (1) the preferred activity and shelter pattern of Atlantic salmon parr during warm summer months, and (2) their response to variations in food availability when balancing growth rate (G) and mortality risk (M), as expressed through time out of shelter. We differentiated among four potential responses to reduced food availability: (1) no response; (2) G decreases but M remains constant; (3) G remains constant but M increases; and (4) G decreases and M increases. 4. Time exposed from shelter was inversely related to food availability. Fish subject to high food availability were significantly less active during the day than those with restricted rations. However, food availability had no significant effect on the extent to which fish were active at night. There was no evidence of variation in growth rate with food availability. 5. Salmon were predominantly nocturnal at high ration levels, consistent with their previously reported behaviour during winter. Rather than switching to diurnal behaviour at high temperatures per se, as previously was supposed, it appears that the fish are diurnal only to the extent needed to sustain a growth rate, and this extent depends on food availability. 6. Atlantic salmon parr modulate the amount of time they are active rather than growth when responding to variations in food availability over an order of magnitude.
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Affiliation(s)
- James E Orpwood
- Cardiff School of Biosciences, Cardiff University Main Building, Museum Avenue, Cardiff CF10 3TL, UK.
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66
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Rickel S, Genin A. Twilight transitions in coral reef fish: the input of light-induced changes in foraging behaviour. Anim Behav 2005. [DOI: 10.1016/j.anbehav.2004.10.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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67
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Cunjak RA, Roussel JM, Gray MA, Dietrich JP, Cartwright DF, Munkittrick KR, Jardine TD. Using stable isotope analysis with telemetry or mark-recapture data to identify fish movement and foraging. Oecologia 2005; 144:636-46. [PMID: 15959824 DOI: 10.1007/s00442-005-0101-9] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Accepted: 03/11/2005] [Indexed: 11/25/2022]
Abstract
Information about animal movements has often been inferred from stable isotope analysis (SIA), but is dependent on animals assimilating site-specific isotopic signatures via diet. This potential weakness in ecological interpretation can be overcome by using other investigative tools that provide precise information about individual movement patterns. In this paper, we demonstrate the value of combining SIA with telemetry or mark-recapture data from trapping, electrofishing and remote detection of individuals to study the movement and feeding ecology of fishes in different habitats. In a fjord lake system in Newfoundland, Canada, juvenile Atlantic salmon delayed downstream migration (smolts) or actively moved into a large lake (parr) where they foraged for periods reflecting different life history strategies. In the Miramichi River (New Brunswick, Canada), SIA provided evidence of distinct foraging habitats (tributary versus large river). By tracking fish implanted with passive integrated transponder (PIT) tags, we distinguished between movements related to foraging versus seeking cool water refugia during high temperature events. Finally, site fidelity and limited mobility of slimy sculpin, a small benthic fish, was established where delta13C in muscle tissue showed a progressive enrichment downstream and where a median displacement of <10 m was estimated for sculpin tagged with PIT tags. Technological improvements have permitted non-destructive tissue sampling of wild fishes for SIA, and the tagging and remote detection of animals smaller than was previously possible. These advancements and the combination of investigative tools promise new insights into animal ecology.
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Affiliation(s)
- R A Cunjak
- Canadian Rivers Institute and Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB, Canada, E3B 5A3.
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68
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Muñoz-Delgado J, Corsi-Cabrera M, Canales-Espinosa D, Santillán-Doherty AM, Erkert HG. Astronomical and meteorological parameters and rest-activity rhythm in the spider monkey Ateles geoffroyi. Physiol Behav 2005; 83:107-17. [PMID: 15501497 DOI: 10.1016/j.physbeh.2004.07.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Revised: 06/05/2004] [Accepted: 07/29/2004] [Indexed: 10/26/2022]
Abstract
UNLABELLED All animals including primates show regular variations in their behavioural activities and physiological functions. In numerous species diel, ultradian, infradian, annual and/or lunar rhythms have been established; however, the use of the focal sampling method does not provide information on hour-to-hour nor day-to-day variations. In behavioural field studies dealing with primate activity rhythms and their modulation by environmental variables the possible dual, synchronizing and/or masking effect of these variables is often ignored. In the present study, we analyze the relation between astronomical and meteorological parameters and various parameters of the rest-activity rhythm in Ateles geoffroyi, a species scarcely investigated with respect to biological rhythms. These Ateles were kept under semi-natural conditions, exposed to natural light, temperature and humidity cycles, and sky state. Motor activity was recorded with actiwatch accelerometers during 180 days (5-min intervals), starting from the autumn equinox. RESULTS Ateles is active throughout the day, rests during the night and presents bimodal activity. Activity time, onset and end of activity as well as the times of their two activity peaks were significantly correlated with duration of the solar day and sunrise or sunset time. The behavioural parameters also correlated with ambient temperature. Climate factors and sky-state significantly influenced the duration and times of onset and end of activity. Our findings identified a clear modulation of the rest-activity pattern by astronomical variables serving as Zeitgebers, such as the natural light-dark cycle, and by masking effects of meteorological factors (temperature, weather and cloudiness), as well as of artificial variables introduced by the interaction with man.
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Affiliation(s)
- Jairo Muñoz-Delgado
- Departamento de Etología, Psicobiología y Conducta, Subdirección de Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente, México, DF, México.
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69
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Railsback SF, Harvey BC, Hayse JW, LaGory KE. TESTS OF THEORY FOR DIEL VARIATION IN SALMONID FEEDING ACTIVITY AND HABITAT USE. Ecology 2005. [DOI: 10.1890/04-1178] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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70
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Hansen EA, Closs GP. Diel activity and home range size in relation to food supply in a drift-feeding stream fish. Behav Ecol 2005. [DOI: 10.1093/beheco/ari036] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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71
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72
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FINSTAD ANDERSG, FORSETH TORBJØRN, NAESJE TORF, UGEDAL OLA. The importance of ice cover for energy turnover in juvenile Atlantic salmon. J Anim Ecol 2004. [DOI: 10.1111/j.0021-8790.2004.00871.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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73
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Kronfeld-Schor N, Dayan T. Partitioning of Time as an Ecological Resource. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2003. [DOI: 10.1146/annurev.ecolsys.34.011802.132435] [Citation(s) in RCA: 556] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Tamar Dayan
- Department of Zoology, Tel Aviv University, Tel Aviv 69978, Israel;
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74
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Jones M, Laurila A, Peuhkuri N, Piironen J, Seppä T. Timing an ontogenetic niche shift: responses of emerging salmon alevins to chemical cues from predators and competitors. OIKOS 2003. [DOI: 10.1034/j.1600-0706.2003.12347.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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75
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Pearre S. Eat and run? The hunger/satiation hypothesis in vertical migration: history, evidence and consequences. Biol Rev Camb Philos Soc 2003; 78:1-79. [PMID: 12620061 DOI: 10.1017/s146479310200595x] [Citation(s) in RCA: 220] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The study of vertical migrations in aquatic organisms has a long and colourful history, much of it to do with the effects of changing sampling technology on our understanding of the phenomenon. However, the overwhelming majority of such studies carried out today still depend on detecting differences in vertical distribution profiles during some course of time, or acoustic echoes of migrating bands of organisms. These can not distinguish migratory activity of individual organisms, but can only assess net results of mass transfers of populations, which may integrate many individual migrations. This is an important distinction, for without knowing the actual movements of individuals it seems unlikely that we will be able to understand their causes, nor the effects of vertical migrations on the environment or on the migrators themselves. This review examines evidence for individual vertical movements gathered from 'tracers', mainly gut contents, and reviews the evidence for the hypothesis that such movements are in fact driven by hunger and satiation. The more recently appreciated vertical migrations of phytoplankters and their similarities in form and driving forces to those of zooplankton and nekton are also discussed. Finally, the role of vertical migrators in vertical fluxes of materials is discussed, along with the consequences of satiation-driven descent for such estimates.
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Affiliation(s)
- Sifford Pearre
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada B3H 3M2
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76
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Alanärä A, Burns MD, Metcalfe NB. Intraspecific resource partitioning in brown trout: the temporal distribution of foraging is determined by social rank. J Anim Ecol 2002. [DOI: 10.1046/j.0021-8790.2001.00550.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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77
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Metcalfe NB, Steele GI. Changing nutritional status causes a shift in the balance of nocturnal to diurnal activity in European Minnows. Funct Ecol 2001. [DOI: 10.1046/j.1365-2435.2001.00527.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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78
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Bradford MJ, Grout JA, Moodie S. Ecology of juvenile chinook salmon in a small non-natal stream of the Yukon River drainage and the role of ice conditions on their distribution and survival. CAN J ZOOL 2001. [DOI: 10.1139/z01-165] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the ecology of juvenile stream-type chinook salmon (Oncorhynchus tshawytscha) in Croucher Creek, a small non-natal tributary of the upper Yukon River, in 1998 and 1999. Underyearling (age 0+) salmon enter Croucher Creek from the Yukon River in June, and by midsummer reached an average density of >0.5/m2. Fish were most commonly found in small pools. Their mean size increased until the end of August, but growth virtually ceased after that, when water temperatures fell. Juveniles remained in the stream through winter, and their distribution and survival were strongly influenced by aufeis, a thick layer of ice that develops from the freezing of groundwater. Over-winter survival was not dependent on fish size. Those fish that survived the winter grew rapidly and doubled in body mass in the spring. About 900 yearling fish emigrated from Croucher Creek in late June and early July at a mean length of 89 mm and mass of 7.2 g. Most of the migrants overwintered in a 700 m long reach of the creek that was downstream from groundwater sources and did not experience severe icing conditions. We suggest that small streams may be important habitats for juvenile salmon in the Yukon drainage, especially if there is a year-round source of groundwater flow that creates conditions suitable for overwintering.
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79
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Is the level of aggression and dispersion in territorial fish dependent on light intensity? Anim Behav 2001. [DOI: 10.1006/anbe.2001.1710] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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80
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Petry AC, Schulz UH. Ritmo de alimentação de juvenis de Loricariichthys anus (Siluriformes, Loricariidae) da Lagoa dos Quadros, RS, Brasil. IHERINGIA. SERIE ZOOLOGIA 2000. [DOI: 10.1590/s0073-47212000000200006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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