Lake Sturgeon Geographic Range, Distribution, and Migration Patterns in the Saskatchewan River

2014 ◽  
Vol 143 (6) ◽  
pp. 1555-1561 ◽  
Author(s):  
Van Wishingrad ◽  
Meghan K. Carr ◽  
Michael S. Pollock ◽  
Maud C. O. Ferrari ◽  
Douglas P. Chivers
2020 ◽  
Vol 27 (1) ◽  
pp. 56-63
Author(s):  
Jong-Gil Park ◽  
Chang-uk Park ◽  
Kyoung-Soon Jin ◽  
Yang-Mo Kim ◽  
Hee-Young Kim ◽  
...  

Genetics ◽  
1993 ◽  
Vol 133 (3) ◽  
pp. 711-727
Author(s):  
B K Epperson

Abstract The geographic distribution of genetic variation is an important theoretical and experimental component of population genetics. Previous characterizations of genetic structure of populations have used measures of spatial variance and spatial correlations. Yet a full understanding of the causes and consequences of spatial structure requires complete characterization of the underlying space-time system. This paper examines important interactions between processes and spatial structure in systems of subpopulations with migration and drift, by analyzing correlations of gene frequencies over space and time. We develop methods for studying important features of the complete set of space-time correlations of gene frequencies for the first time in population genetics. These methods also provide a new alternative for studying the purely spatial correlations and the variance, for models with general spatial dimensionalities and migration patterns. These results are obtained by employing theorems, previously unused in population genetics, for space-time autoregressive (STAR) stochastic spatial time series. We include results on systems with subpopulation interactions that have time delay lags (temporal orders) greater than one. We use the space-time correlation structure to develop novel estimators for migration rates that are based on space-time data (samples collected over space and time) rather than on purely spatial data, for real systems. We examine the space-time and spatial correlations for some specific stepping stone migration models. One focus is on the effects of anisotropic migration rates. Partial space-time correlation coefficients can be used for identifying migration patterns. Using STAR models, the spatial, space-time, and partial space-time correlations together provide a framework with an unprecedented level of detail for characterizing, predicting and contrasting space-time theoretical distributions of gene frequencies, and for identifying features such as the pattern of migration and estimating migration rates in experimental studies of genetic variation over space and time.


1980 ◽  
Vol 43 (1) ◽  
pp. 177-194 ◽  
Author(s):  
J.E. Aubin ◽  
M. Osborn ◽  
K. Weber

The localization and migration of centriole duplexes have been studied in PtK2 cells by indirect immunofluorescence microscopy using specific tubulin antibodies. The study demonstrated the usefulness of the immunofluorescence technique to quantitate studies of centriole migration and concomitant events such as cytoplasmic microtubule breakdown in large populations of cells. Centriole duplex locations in normal and Colcemid-treated interphase populations have been compared with duplex locations in prophase cells. A higher percentage of duplexes were found close to the nucleus in prophase than in interphase cells, but approximately 5% of the duplexes remained in the cytoplasm far removed from the nucleus in prophase and throughout the course of duplex separation. Duplex separation occurred along a wide variety of paths and duplexes did not have to be closely juxtaposed to the nuclear envelope for separation to occur. Some duplexes separated in the cytoplasm with no detectable nuclear attachment, with spindles forming far to the side of the condensing chromosomes. The timing of duplex separation did not always coincide either with chromosome condensation or with nuclear membrane breakdown, and in a small percentage of the cells separation occurred as late as prometaphase. These data suggest that normal spindle formation can occur despite the large variability in initial and final centriole duplex location, their migration patterns, and the timing of the different events. Breakdown of cytoplasmic microtubules began in prophase and progressed until prometaphase; the last cytoplasmic microtubules disappeared soon after the loss of the nuclear membrane.


2002 ◽  
Vol 59 (12) ◽  
pp. 1845-1850 ◽  
Author(s):  
Luc A Comeau ◽  
Steven E Campana ◽  
Martin Castonguay

The migration patterns of marine fishes are poorly known, in part owing to the technical limitations associated with tracking the movements of animals in deep water. Here we document a large-scale, directed, migration of Atlantic cod (Gadus morhua) off eastern Canada. Our approach was based on the acoustic tagging of 126 fish and the deployment of 69 subsurface receivers, stretching over a 160-km distance along the edge of the Laurentian Channel. After 1 year of automated recording, we found that 65% of the fish migrated out of coastal waters in two distinct runs during the summer–autumn period. The offshore-migrating fish overwintered in deep Laurentian Channel waters, returning inshore in April. Individual migration routes and migration timing were variable, indicating that the cod did not aggregate in large schools during the seasonal migration events.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Cinzia Podda ◽  
Andrea Sabatini ◽  
Francesco Palmas ◽  
Antonio Pusceddu

Catadromous fish species are very important organisms for their ecological, economical, and cultural value. For its complex life species catadromous fish result in worldwide decline since the beginning of the 20th century. Among the most iconic catadromous species, the European eel Anguilla anguilla L. 1758 has aroused considerable interest since very ancient times. Because, to date, many aspects of their life cycle remain relatively unknown, to implement our knowledge about the main natural and anthropogenic threats to its survivorship and identify possible solutions to preserve it, in this narrative review, we present the state of the knowledge about the life cycle, habitat occupancy, recruitment, and migration patterns of the European eel and about the major threats most likely have contributed to the decline of eels’ populations.


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