The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Jiangshiou Hwang - One of the best experts on this subject based on the ideXlab platform.
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Diel Vertical Migration of the planktonic copepods at an upwelling station north of taiwan western north pacific
Journal of Plankton Research, 2004Co-Authors: Changtai Shih, Jiangshiou HwangAbstract:A total of 178 copepod species were identified in an upwelling area of the Mienhua Canyon off northern Taiwan, western North Pacific during a spring cruise in 1995. Paracalanus aculeatus; Oncaea venusta and Clausocalanus furcatus were the three dominant species, comprising 43% of the total copepod numbers. Most copepod species performed normal Diel Vertical Migration, descending during daytime and ascending at night to different depth zones and with different rates. Some dominant copepod species, such as P. aculeatus, C. furcatus, Temora discaudata and Canthocalanus pauper, apparently congregated in the surface water (between 0 and ∼1 m) at night but became sparse in the upper 250 m of the water column during the day. Some copepods stayed in deeper water and occasionally ascended to the subsurface layer at night or twilight (i.e. Subeucalanus mucronatus), while others exhibited no apparent Diel Vertical Migration or reverse Diel Vertical Migration in the depth below the subsurface layer.
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SHORT COMMUNICATION Diel Vertical Migration of the planktonic copepods at an upwelling station north of Taiwan, western North Pacific
2004Co-Authors: Changtai Shih, Jiangshiou HwangAbstract:A total of 178 copepod species were identified in an upwelling area of the Mienhua Canyon off northern Taiwan, western North Pacific during a spring cruise in 1995. Paracalanus aculeatus, Oncaea venusta and Clausocalanus furcatus were the three dominant species, comprising 43% of the total copepod numbers. Most copepod species performed normal Diel Vertical Migration, descending during daytime and ascending at night to different depth zones and with different rates. Some dominant copepod species, such as P. aculeatus, C. furcatus, Temora discaudata and Canthocalanus pauper, apparently congregated in the surface water (between 0 and � 1 m) at night but became sparse in the upper 250 m of the water column during the day. Some copepods stayed in deeper water and occasionally ascended to the subsurface layer at night or twilight (i.e. Subeucalanus mucronatus), while others exhibited no apparent Diel Vertical Migration or reverse Diel Vertical Migration in the depth below the subsurface layer.
Graeme C. Hays - One of the best experts on this subject based on the ideXlab platform.
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Long-term changes in the Diel Vertical Migration behaviour of zooplankton
Marine Ecology Progress Series, 1996Co-Authors: Graeme C. Hays, A.j. Warner, Lefevre DAbstract:Samples historically collected and analysed by the Continuous Plankton Recorder survey were used to examine long-term (1958 to 1994) patterns in the normal Diel Vertical Migration (NDVM) behaviour of 7 copepod taxa in the North Sea: Calanus finmarchicus C5-C6; Calanus spp. C1-C4; Centropages typicus; Centropages hamatus; Temora longicornis; Acartia clausii and Para-Pseudocalanus (this last group included all Paracalanus and Pseudocalanus species). The ratio of night:day abundance near the surface was used as a measure of the extent of NDVM. For all 7 taxa, the extent of NDVM between 1958 and 1994 co-varied with the abundance of herring Clupea harengus in the North Sea. Fisheries data show that during this period the herring stock was a good indicator of the overall abundance of planktivorous fish in the North Sea. These results suggest that changes in the abundance of planktivorous fish in the North Sea over recent decades have resulted in modifications in the NDVM behaviour of many zooplankton taxa.
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Large-scale patterns of Diel Vertical Migration in the North Atlantic
Deep Sea Research Part I: Oceanographic Research Papers, 1996Co-Authors: Graeme C. HaysAbstract:Samples historically collected and analysed by the Continuous Plankton Recorder (CPR) survey in the North Atlantic were used to examine large-scale spatial patterns in both the normal Diel Vertical Migration (normal DVM) behaviour and the mean body size within epi-pelagic copepod communities. Normal DVM was most marked in the northwest Atlantic and less marked in the northeast Atlantic and in shallow coastal areas such as around the U.K. and on the Grand Banks of Newfoundland. These patterns of normal DVM were strongly correlated with patterns of mean body size, with normal DVM being more marked in those areas where larger species predominated. In both the northwest and northeast Atlantic, marked seasonal changes occurred in the migrating biomass. In the northwest Atlantic, Euchaeta norvegica and Calanus finmarchicus were the most important contributors to the total migrating biomass, while in the northeast Atlantic the most important contributors were E. norvegica, Metridia lucens and Pleuromamma robusta.
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Diel Vertical Migration behaviour of Calanus hyperboreus at temperate latitudes
Marine Ecology Progress Series, 1995Co-Authors: Graeme C. HaysAbstract:Samples historically collected and analysed by the Continuous Plankton Recorder survey in the North Atlantic and adjacent seas were used to examine temporal patterns in the near-surface abundance of copepodite stages V and VI Calanus hyperboreus (n = a total of 32836 samples; mean latitude of samples = 54* N, SD = 6.7*). The occurrence of CV and VI C. hyperboreus was largely restricted to samples collected in April, May and June. During this period there was a Diel cycle in near-surface abundance which was consistent with a normal pattern of Diel Vertical Migration. For example, CV-VI C. hyperboreus were 1.9 times more abundant at night than during the day, a difference which was highly significant (t-test, t5072 = 3.9, p < 0.001). The ratio of night:day abundance was similar in CV-VI C. finmarchicus (night:day abundance = 1.4), but markedly higher in CV-VI Metridia lucens (night:day abundance = 12.3) and CV-VI M. longa (night:day abundance = 15.0).
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interspecific differences in the Diel Vertical Migration of marine copepods the implications of size color and morphology
Limnology and Oceanography, 1994Co-Authors: Graeme C. Hays, C A Proctor, A W G John, A.j. WarnerAbstract:Samples collected by continuous plankton recorders (CPRs) between 1948 and 1992 were used to describe the Diel Vertical Migration (DVM) behavior of 4 1 copepod taxa in the northeast Atlantic between 45 and 55“N and 11 and 3 1”W. A total of 13,622 samples, each representing - 18.5 km (10 nm) of tow, were analyzed. Since CPRs are towed in near-surface waters, taxa that exhibit DVM occur predominantly in samples taken at night. Larger taxa showed significantly stronger DVM, with body size explaining 47% of the intertaxa variation in DVM. For small taxa ( 1 mm wide) the residual variation in DVM was correlated with body morphology but not with carotenoid pigment levels, with more elongate copepods not exhibiting DVM. Diel Vertical Migration (DVM) occurs in a wide range of both marine and freshwater copepods as well as in a variety of other zooplankton, with the “normal” pattern being movement from greater depths during the day to shallower depths at night (Lampert 1989). The ubiquity of DVM in zooplankton communities has provoked considerable and extended debate as to its functional significance (see Lampert 1989). Although it has been suggested that DVM may provide a metabolic advantage associated with the Diel movement across a thermocline (McLaren 1963), this hypothesis is now generally refuted (Lampert 1989). Alternatively, Zaret and Suffem (1976) suggested that DVM may be an antipredator behavior, with populations moving to a greater depth during the day to reduce risk from visual predators. A considerable amount of both field and experimental evidence has accumulated to support this predator-evasion hypothesis. For example, Gliwicz (1986) reported that the
Akinori Ohno - One of the best experts on this subject based on the ideXlab platform.
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Diel Vertical Migration of myctophid fishes family myctophidae in the transitional waters of the western north pacific
Fisheries Oceanography, 1999Co-Authors: Hikaru Watanabe, Masatoshi Moku, Kouichi Kawaguchi, Kimie Ishimaru, Akinori OhnoAbstract:The Diel Vertical Migration patterns of adult myctophid fishes were determined in the transitional waters of the western North Pacific off Japan, using day–night sampling from 20 to 700 m depths with a commercial otter trawl in the summer of 1995. A total of 12 species belonging to 9 genera were collected. Four patterns were recognized in the Diel Vertical Migration of 11 of the 12 species. (1) Migrants showing clear day–night habitat separation with peak abundance above 200 m at night: Symbolophorus californiensis, Tarletonbeania taylori, Notoscopelus japonicus, Diaphus theta, Ceratoscopelus warmingi, and Diaphus gigas. (2) Semi-migrants, in which part of the population often remains in the daytime habitat at night. The distribution depths of migratory and nonmigratory individuals do not overlap: Stenobrachius leucopsarus. (3) Passive-migrants, in which there is no separation of day–night habitats, but the upper limit of daytime distribution depth shifts to a shallower layer at night, probably as the fish follow migratory prey: Lampanyctus jordani. (4) Nonmigrants: Stenobrachius nannochir, Lampanyctus regalis (> 140 mm SL), and Protomyctophum thompsoni. The day–night habitat temperature ranges are also given for the 11 species. No remarkable east–west differences were seen in the Vertical Migration patterns compared with previous knowledge of eight of these species in the eastern Pacific. The Diel Migration patterns are newly described for three other species endemic to the western Pacific. The standing stock of myctophids in the study area was conservatively estimated at 18.5 ± 4.7 g m−2 (avg. ± SD).
Changtai Shih - One of the best experts on this subject based on the ideXlab platform.
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Diel Vertical Migration of the planktonic copepods at an upwelling station north of taiwan western north pacific
Journal of Plankton Research, 2004Co-Authors: Changtai Shih, Jiangshiou HwangAbstract:A total of 178 copepod species were identified in an upwelling area of the Mienhua Canyon off northern Taiwan, western North Pacific during a spring cruise in 1995. Paracalanus aculeatus; Oncaea venusta and Clausocalanus furcatus were the three dominant species, comprising 43% of the total copepod numbers. Most copepod species performed normal Diel Vertical Migration, descending during daytime and ascending at night to different depth zones and with different rates. Some dominant copepod species, such as P. aculeatus, C. furcatus, Temora discaudata and Canthocalanus pauper, apparently congregated in the surface water (between 0 and ∼1 m) at night but became sparse in the upper 250 m of the water column during the day. Some copepods stayed in deeper water and occasionally ascended to the subsurface layer at night or twilight (i.e. Subeucalanus mucronatus), while others exhibited no apparent Diel Vertical Migration or reverse Diel Vertical Migration in the depth below the subsurface layer.
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SHORT COMMUNICATION Diel Vertical Migration of the planktonic copepods at an upwelling station north of Taiwan, western North Pacific
2004Co-Authors: Changtai Shih, Jiangshiou HwangAbstract:A total of 178 copepod species were identified in an upwelling area of the Mienhua Canyon off northern Taiwan, western North Pacific during a spring cruise in 1995. Paracalanus aculeatus, Oncaea venusta and Clausocalanus furcatus were the three dominant species, comprising 43% of the total copepod numbers. Most copepod species performed normal Diel Vertical Migration, descending during daytime and ascending at night to different depth zones and with different rates. Some dominant copepod species, such as P. aculeatus, C. furcatus, Temora discaudata and Canthocalanus pauper, apparently congregated in the surface water (between 0 and � 1 m) at night but became sparse in the upper 250 m of the water column during the day. Some copepods stayed in deeper water and occasionally ascended to the subsurface layer at night or twilight (i.e. Subeucalanus mucronatus), while others exhibited no apparent Diel Vertical Migration or reverse Diel Vertical Migration in the depth below the subsurface layer.
Richard B. Forward - One of the best experts on this subject based on the ideXlab platform.
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ZOOPLANKTON Diel Vertical Migration — A REVIEW OF PROXIMATE CONTROL
Oceanography and Marine Biology, 2016Co-Authors: Jonathan H. Cohen, Richard B. ForwardAbstract:Diel Vertical Migration (DVM) is a characteristic behavioural pattern performed by zooplankton in which their Vertical distribution changes over the 24-h day. Here the proximate control of zooplankton DVM is reviewed. Light has emerged as the major proximate cue controlling DVM behaviour and the understanding of zooplankton visual physiology and the light-mediated behaviour underlying DVM is expanding. Field and laboratory evidence exist to support each of the three major hypotheses for the exogenous role of light in DVM: (1) preferendum or isolume, (2) absolute intensity threshold, and (3) relative rate of change. Light may also play an endogenous role in DVM by entraining circadian rhythms in Vertical movement or activity. This appreciation of the role of light has improved modelling efforts into the causes and consequences of DVM. The most important recent advance in the study of DVM is the recognition that this behaviour is a phenotypic response in many species and is most commonly activated by chemical cues (kairomones) from fish predators. High levels of kairomones signal high levels of predation pressure, and DVM-related photobehaviours, such as swimming responses on relative rates of irradiance change, are altered such that Migration occurs and zooplankton achieve a refuge from visual predators.
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zooplankton Diel Vertical Migration a review of proximate control
Oceanography and Marine Biology, 2009Co-Authors: Jonathan H. Cohen, Richard B. ForwardAbstract:Diel Vertical Migration (DVM) is a characteristic behavioural pattern performed by zooplankton in which their Vertical distribution changes over the 24-h day. Here the proximate control of zooplankton DVM is reviewed. Light has emerged as the major proximate cue controlling DVM behaviour and the understanding of zooplankton visual physiology and the light-mediated behaviour underlying DVM is expanding. Field and laboratory evidence exist to support each of the three major hypotheses for the exogenous role of light in DVM: (1) preferendum or isolume, (2) absolute intensity threshold, and (3) relative rate of change. Light may also play an endogenous role in DVM by entraining circadian rhythms in Vertical movement or activity. This appreciation of the role of light has improved modelling efforts into the causes and consequences of DVM. The most important recent advance in the study of DVM is the recognition that this behaviour is a phenotypic response in many species and is most commonly activated by chemical cues (kairomones) from fish predators. High levels of kairomones signal high levels of predation pressure, and DVM-related photobehaviours, such as swimming responses on relative rates of irradiance change, are altered such that Migration occurs and zooplankton achieve a refuge from visual predators.