A Hydroacoustic Study of the Pelagic Spawning Behavior of Whitefish (Coregonus lavaretus) in Lake Constance

1991 ◽  
Vol 48 (6) ◽  
pp. 995-1002 ◽  
Author(s):  
Reiner Eckmann
Keyword(s):  
Vertical Distribution ◽  
Distribution Patterns ◽  
Target Strength ◽  
Coregonus Lavaretus ◽  
Upward Migration ◽  
Vertical Range ◽  
Abundance Estimates ◽  
Lake Bottom ◽  
Total Fish ◽  
Pelagic Spawning

The horizontal and vertical distribution patterns of pelagic spawning whitefish (Coregonus lavaretus) were studied by echosounding from the end of the growing season (early November) until after spawning (late January). During early November, whitefish inhabited similar depths during day and night, but during spawning displayed vertical migrations of up to 50 m amplitude: whitefish ascended at dusk and descended at dawn. At the end of the spawning season, vertical migrations ceased. Juveniles took part in the daily migrations, but only sexually mature specimens invaded the uppermost 10 m of water, while maturing and juvenile individuals and spent females stayed deeper during the night. This vertical distribution pattern is interpreted as a means to increase encounter probability among mature specimens. Diel vertical migration of the entire population is suggested to be an aid to avoid cannibalism on freshly spawned eggs during settling to the lake bottom. Total fish density estimates increased during upward migration and decreased during downward migration; this may be the result of differences in target strength caused by both reduced swimbladder volume and positive tilt while in deep waters. Highly reproducible abundance estimates were obtained during night when whitefish were evenly distributed at the top of their vertical range.

Diel vertical distribution of early marine phase juvenile pink salmon (Oncorhynchus gorbuscha) and behaviour when exposed to salmon louse (Lepeophtheirus salmonis)

2011 ◽  
Vol 89 (9) ◽  
pp. 796-807 ◽  
Author(s):  
S. Tang ◽  
A.G. Lewis ◽  
M. Sackville ◽  
L. Nendick ◽  
C. DiBacco ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Pink Salmon ◽  
Distribution Patterns ◽  
Oncorhynchus Gorbuscha ◽  
Lepeophtheirus Salmonis ◽  
Night Time ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Louse ◽  
Seawater Acclimation

We observed diel vertical migration patterns in juvenile pink salmon ( Oncorhynchus gorbuscha (Walbaum, 1792)) and tested the hypothesis that fish behaviour is altered by exposure to sea lice copepodids. Experiments involved replicated field deployments of a large (9 m) plankton column, which provided a vertical distribution enclosure under natural light and salinity conditions. Diel vertical distributions of juvenile pink salmon were observed during the first 3 weeks of seawater acclimation in both the presence and the absence of the ectoparasitic salmon louse ( Lepeophtheirus salmonis (Krøyer, 1838)). Immediately upon entering seawater, juvenile pink salmon preferred the top 1 m of the water column, but they moved significantly deeper down the vertical water column as seawater acclimation time increased. A significant diel migration pattern was observed, which involved a preference for the surface at night-time, compared with daytime. When fish in the column were exposed to L. salmonis copepodids for 3 h, 43%–62% of fish became infected, fish expanded their vertical distribution range, and significant changes in vertical distribution patterns were observed.

scholarly journals Reptilia, Squamata, Amphisbaenidae, Amphisbaena cegei Montero, 1997, and Reptilia, Squamata, Teiidae, Tupinambis rufescens (Günther, 1871): Vertical range extension

Check List ◽  
2010 ◽  
Vol 6 (4) ◽  
pp. 503
Author(s):  
Martin Jansen ◽  
Gunther Köhler
Keyword(s):  
Vertical Distribution ◽  
Dry Forest ◽  
Range Extension ◽  
Vertical Range

We report on records of Amphisbaena cegei and Tupinambis rufescens in the Bolivian Inter-Andean Dry Forest (Bolivia) that extend the known vertical distribution.

scholarly journals Patterns of distribution and abundance of larval phosichthyidae (actinopterygii, stomiiformes) in southeastern Brazilian waters

2011 ◽  
Vol 59 (3) ◽  
pp. 213-229 ◽  
Author(s):  
Cássia Gôngora Goçalo ◽  
Mario Katsuragawa ◽  
Ilson Carlos Almeida da Silveira
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Distribution Patterns ◽  
Southeastern Brazil ◽  
Patterns Of Distribution ◽  
Oceanic Region ◽  
Brazil Current ◽  
Horizontal And Vertical Distribution

Horizontal and vertical distribution patterns and abundance of larval phosichthyids were investigated from oblique and depth-stratified towns off Southeastern brazilian waters, from São Tomé cape (41ºW.; 22ºS.) to São Sebastião island (45ºW.; 24ºS.). The sampling was performed during two cruises (January/2002 -summer; August/2002 -winter). Overall 538 larvae of Phosichthyidae were collected during summer and 158 in the winter. Three species, Pollichthys mauli, Vinciguerria nimbaria and Ichthyioccoccus sp. occurred in the area, but Ichthyioccoccus sp. was extremely rare represented by only one specimen, caught in the oceanic region during the summer. Geographically, larval were concentrated in the oceanic region, and vertically distributed mainly between the surface and 80 m depth in the summer and winter. Larvae were more abundant during the night, performing a diel vertical migration in the water column. The results suggest that the meandering and eddies of Brazil Current play important role on the transport and distribution patterns of larval phosichthyids over the oceanic and neritic area in the Southeastern Brazil.

Investigating vertical distribution patterns of lower tropospheric PM2.5 using unmanned aerial vehicle measurements

2018 ◽  
Vol 173 ◽  
pp. 62-71 ◽  
Author(s):  
Xiao-Bing Li ◽  
Dong-Sheng Wang ◽  
Qing-Chang Lu ◽  
Zhong-Ren Peng ◽  
Zhan-Yong Wang
Keyword(s):  
Vertical Distribution ◽  
Unmanned Aerial Vehicle ◽  
Distribution Patterns ◽  
Aerial Vehicle

Distribution and ecology of epiphytic bryophytes and lichens in dry evergreen forest of Guyana

1989 ◽  
Vol 5 (2) ◽  
pp. 131-150 ◽  
Author(s):  
J. H. C. Cornelissen ◽  
H. Ter Steege
Keyword(s):  
South America ◽  
Vertical Distribution ◽  
Ecological Study ◽  
Distribution Patterns ◽  
Life Forms ◽  
Evergreen Forest ◽  
The Sun ◽  
Dry Evergreen Forest ◽  
Distribution And Ecology

ABSTRACTA floristic and ecological study of epiphytic bryophytes and lichens on standing mature Eperua trees was carried out in dry evergreen (walaba) forest in Guyana, South America. The trees were sampled from their base up to the highest canopy twigs, using mountaineering techniques. Clear vertical distribution patterns of epiphytic species and life-forms were found. Many species, particularly foliose lichens, appear to be preferential or exclusive to either Eperua grandiflora or E. falcata (Leguminosae), which are the dominant trees in the walaba forest. Special attention is given to the species-rich epiphyte vegetation on the upper canopy twigs, which include two categories of species: the sun epiphytes and the pioneers (facultative epiphylls).

Influences on the natural reproduction of whitefish (Coregonus lavaretus) in Lake Constance

2009 ◽  
Vol 66 (4) ◽  
pp. 547-556 ◽  
Author(s):  
Bernd Wahl ◽  
Herbert Löffler
Keyword(s):  
Age Structure ◽  
Lake Constance ◽  
Coregonus Lavaretus ◽  
Low Oxygen ◽  
Stock Size ◽  
Natural Reproduction ◽  
Lake Bottom ◽  
Oxygen Conditions ◽  
Spawning Time ◽  
The Impact

The conditions for the natural reproduction of whitefish ( Coregonus lavaretus ) in Lake Constance have been subject to strong variations during recent decades by the impact of fishing and trophic changes. We analysed fluctuations of stock size, age structure, spawning time, and amount of sampled eggs of this species. The onset of spawning altered because of changes in the age structure of the stock. We found a clear relation of spawning time to the mean age of the annual catch and the November epilimnion temperature. The quantity of eggs sampled from the lake bottom with a dredge is in relation to the number of female spawners and may serve as an early indicator for stock size changes. The proportion of viable eggs on the lake floor correlates with oxygen concentrations in deep water. Extremely low oxygen conditions and an almost total loss of eggs occurred when the nutrient levels were high and oxygen regeneration by vertical winter mixing was weak. A mathematical model serves to interpret the changing abundance of living eggs on the lake bottom over the course of a season and is also used to estimate mortality rates.

scholarly journals Chlorophyll-a vertical distribution patterns during summer in the Bay of La Paz, Gulf of California, Mexico

2019 ◽  
Vol 45 (2) ◽  
pp. 109-115
Author(s):  
Elizabeth Durán-Campos ◽  
María Adela Monreal-Gómez ◽  
David Alberto Salas de León ◽  
Erik Coria-Monter
Keyword(s):  
Vertical Distribution ◽  
Chlorophyll A ◽  
Gulf Of California ◽  
Distribution Patterns ◽  
La Paz
Sign in / Sign up

Export Citation Format

Share Document