Community Structure and Biomass of Euphausiids in the Bay of Fundy

1982 ◽  
Vol 39 (2) ◽  
pp. 326-334 ◽  
Author(s):  
D. W. Kulka ◽  
S. Corey ◽  
T. D. Iles
Keyword(s):  
Life History ◽  
Community Structure ◽  
Vertical Migration ◽  
High Intensity ◽  
Sampling Scheme ◽  
Bay Of Fundy ◽  
Migration Patterns ◽  
Life History Stages ◽  
Diurnal Vertical Migration ◽  
Meganyctiphanes Norvegica

Seven species of euphausiids were found in the Bay of Fundy: Meganyctiphanes norvegica, Thysanoessa inermis, T. longicaudata, T. raschii, T. gregaria, Euphausia krohnii, and Nematoscelis megalops (listed in descending order of abundance). A high-intensity sampling scheme during November and March facilitated detailed distributional studies which revealed that M. norvegica, T. inermis, and T. longicaudata each had a specific stationary center of abundance in the study area, and each species performed a different pattern of diurnal vertical migration. Meganyctiphanes norvegica formed 90% (constituting 70 kt) of the euphausiids. The last four species were occasional immigrants from areas south of the Bay of Fundy. From the relationships between life history stages, vertical migration patterns, distribution, and currents in the Fundy Region, we suggest that these euphausiid species form stocks.Key words: euphausiids, Meganyctiphanes norvegica, Thysanoessa inermis, Thysanoessa longicaudata, biomass, community structure, stock, Bay of Fundy

Migratory behaviour of captive white-crowned sparrows, Zonotrichia leucophrys gambelii, differs during autumn and spring migration

Behaviour ◽  
2006 ◽  
Vol 143 (10) ◽  
pp. 1219-1240 ◽  
Author(s):  
Marilyn Ramenofsky ◽  
Renée Agatsuma
Keyword(s):  
Life History ◽  
High Intensity ◽  
Primary Source ◽  
Migratory Restlessness ◽  
Long Distance ◽  
Free Living ◽  
Zonotrichia Leucophrys ◽  
Life History Stages ◽  
In Captivity ◽  
Zonotrichia Leucophrys Gambelii

AbstractGambel's white-crown sparrow (Zonotorichia leucophrys gambelii) is a long-distance, over-land migrant. In captivity birds display many characteristics of the autumn and spring migratory life history stages that include hyperphagia, fattening and high intensity nocturnal activity termed migratory restlessness or Zugunruhe. We recorded the behaviour of captive birds while simultaneously collecting 24 h locomotor activity. These data were used to define the behaviour displayed by captive birds during autumn and spring in order to compare the two migratory stages and to draw inferences for free-living birds. The predominant behaviour during day and nighttime was rest. Feeding occurred only during daylight hours but at a greater frequency in autumn than spring. Birds generally used their feet as the primary source of locomotion during the day termed 'jump'. During the night, two distinct behaviours, 'beak-up flight' and 'beak-up' involving high intensity wing motions were observed and considered components of migratory restlessness. The frequency of the 'beak-up flight' was greatest during spring and associated with the enhanced tempo of vernal migration. In both stages, migratory restlessness was preceded by a quiescent phase, the occurrence of which differed and related to time available for foraging and length of the night. Given these findings, we hypothesize that diel behaviours displayed by autumn and spring migrants in captivity highlight distinctions between the two life history stages.

Effects of ultraviolet radiation on life-history stages of anurans from Ontario, Canada

1995 ◽  
Vol 73 (12) ◽  
pp. 2292-2301 ◽  
Author(s):  
Karen P. Grant ◽  
Lawrence E. Licht
Keyword(s):  
Life History ◽  
High Intensity ◽  
Rana Sylvatica ◽  
Ultraviolet B ◽  
Egg Mass ◽  
Hyla Versicolor ◽  
Population Declines ◽  
Life History Stages ◽  
Embryo Stage

We tested the effects of ultraviolet-a (uv-a) and ultraviolet-b (uv-b) radiation on life-history stages of the anurans Bufo americanus, Hyla versicolor, Rana clamitans, and Rana sylvatica. No effect of uv-a was found on eggs or larvae even at exposures twice the intensity of normal outdoor levels. Only R. sylvatica was tested in the embryo stage. All embryos exposed to 30 min or more of artificially high intensity uv-b died. After exposure to artificially high intensity uv-b of 15 min or less, or at ecologically relevant levels, there was no effect on hatching success. The proportion of abnormal embryos after exposure to 10 or 15 min of artificially high intensity treatment was higher at 12 °C than at 20 °C. The jelly surrounding the ova can effectively reduce uv-b transmission through the egg mass. Of the four species tested, only larval R. clamitans showed some tolerance of artificially high uv-b levels, but development of the survivors was arrested and metamorphosis was not initiated. Ecologically relevant doses of uv-b had no effect on developmental period, duration of metamorphic climax, or mass at metamorphosis in B. americanus, H. versicolor, or R. sylvatica. Whereas all metamorphosed juvenile R. clamitans and R. sylvatica died after exposure to high-intensity uv-b, some B. americanus survived. Older B. americanus exposed for the same length of time had higher survivorship than younger animals. The role of uv radiation in presumed amphibian population declines is discussed.

A new species of Haploops (Amphipoda, Ampeliscidae) from the Bay of Fundy

1982 ◽  
Vol 60 (5) ◽  
pp. 962-967 ◽  
Author(s):  
D. J. Wildish ◽  
J. J. Dickinson
Keyword(s):  
Life History ◽  
New Species ◽  
Bay Of Fundy ◽  
Life History Stages ◽  
Arctic Regions ◽  
A New Species

Haploops fundiensis n. sp. is described and figured in immature and mature life-history stages, inclusive of the pelagic male, from samples taken at 80 m in the Bay of Fundy. Taxonomic affinities and distinguishing characteristics of H. fundiensis n. sp. are discussed and a key is provided for distinguishing the presently known species of Haploops from the northwestern Atlantic and Arctic regions.

scholarly journals The movement ecology of seagrasses

2014 ◽  
Vol 281 (1795) ◽  
pp. 20140878 ◽  
Author(s):  
Kathryn McMahon ◽  
Kor-jent van Dijk ◽  
Leonardo Ruiz-Montoya ◽  
Gary A. Kendrick ◽  
Siegfried L. Krauss ◽  
...  
Keyword(s):  
Life History ◽  
Clonal Growth ◽  
Movement Ecology ◽  
Future Research ◽  
The Novel ◽  
Long Distance ◽  
Spatial And Temporal Scales ◽  
Life History Stages ◽  
Research Areas ◽  
Time Movement

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified.

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