scholarly journals Effects of fish chemical cues on vertical migration behavior of Chaoborus

1990 ◽  
Vol 35 (7) ◽  
pp. 1456-1468 ◽  
Author(s):  
Sara F. Tjossem
Keyword(s):  
Vertical Migration ◽  
Chemical Cues ◽  
Migration Behavior

Seasonal changes in the diel vertical migration of Chaoborus punctipennis larval instars

2014 ◽  
Vol 71 (5) ◽  
pp. 665-674 ◽  
Author(s):  
Lauren Emily Barth ◽  
W. Gary Sprules ◽  
Mathew Wells ◽  
Melissa Coman
Keyword(s):  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Acoustic Doppler Current Profiler ◽  
Acoustic Backscatter ◽  
Migration Behavior ◽  
Larval Instars ◽  
Reverse Migration ◽  
Coregonus Artedi ◽  
Chaoborus Punctipennis ◽  
Current Profiler

We describe a novel seasonal shift in the vertical migration behavior of Chaoborus punctipennis second-instar larvae in Lake Opeongo, Ontario. An upward-looking 600 kHz acoustic Doppler current profiler (ADCP) moored at a fixed 22 m station in the lake recorded acoustic backscatter continuously during the study period. Zooplankton samples collected indicated that the abundance of C. punctipennis larval instars accounted for the greatest proportion of variance in the linear backscatter from the ADCP. The large fourth-instar larvae underwent normal diel vertical migration throughout the study. Smaller second-instar larvae underwent reverse migration during late June but switched to normal migration by late July. The acoustic record indicates that the switch occurred over a few days around late June, and at this time a double vertical migration appeared with the second instars leading and following the migration of fourth instars. We speculate that these changes in the migration of second instars are driven by seasonal shifts in predation risk from larval cisco (Coregonus artedi) and by the need to minimize spatial overlap with the larger fourth instars.

scholarly journals Diel vertical migration behavior of Calanus finmarchicus and its influence on right and sei whale occurrence

2011 ◽  
Vol 423 ◽  
pp. 167-184 ◽  
Author(s):  
MF Baumgartner ◽  
NSJ Lysiak ◽  
C Schuman ◽  
J Urban-Rich ◽  
FW Wenzel
Keyword(s):  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Calanus Finmarchicus ◽  
Migration Behavior

Mysis relicta Assimilation of Hexachlorobiphenyl from Sediments

1991 ◽  
Vol 48 (2) ◽  
pp. 284-289 ◽  
Author(s):  
J. Val Klump ◽  
Jerry L. Kaster ◽  
Michael E. Sierszen
Keyword(s):  
Particle Size ◽  
Vertical Migration ◽  
Specific Activity ◽  
Migration Behavior ◽  
Fecal Material ◽  
Selective Feeding ◽  
Deep Lakes ◽  
Mysis Relicta ◽  
Pelagic Environment ◽  
Important Pathway

Assimilation and retention of a PCB congener, 2,4,5,2′,4′,5′-hexachlorobiphenyl (HCBP), by the oppossum shrimp, Mysis relicta, was followed during sediment ingestion and defecation using a 14C label. Uptake was rapid and essentially linear, with mysids reaching a [14C]HCBP specific activity equivalent to that in the labeled sediment within 2 wk. Assimilation efficiencies calculated from the relative depletion of the label in the fecal material averaged 53% (±7%). Sediment ingestion rates calculated from the activity required to supply the label retained were approximately 1 mg∙mysid−1∙d−1, in agreement with published estimates. The distribution of HCBP as a function of particle size indicates that particle-size selective feeding by detritivores can have a significant effect on calculated assimilation efficiencies. Given the vertical migration behavior of M. relicta, sediment ingestion is a potentially important pathway for the reintroduction of sediment-associated contaminants into the pelagic environment of deep lakes.

Acoustic Analysis of Diel Vertical Migration Behavior of Mysis relicta and Kokanee (Oncorhynchus nerka) within Okanagan Lake, British Columbia

1991 ◽  
Vol 48 (1) ◽  
pp. 67-72 ◽  
Author(s):  
David A. Levy
Keyword(s):  
Water Column ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Acoustic Analysis ◽  
Oncorhynchus Nerka ◽  
Target Strength ◽  
Migration Behavior ◽  
Mysis Relicta ◽  
Dual Beam ◽  
Diel Vertical Migrations

Dual-beam acoustic surveys of Okanagan Lake suggested active diel vertical migrations of Mysis relicta and kokanee (Oncorhynchus nerka) within the pelagic zone. Mysis relicta were situated between 90–150 m during the day and migrated upwards into the thermocline region of the water column at night. Two groups of kokanee targets were detected. The first undertook a diel vertical migration and coalesced at dusk with a second, shallow-oriented group of targets. Daytime target strength estimates taken while the two groups were vertically segregated in the water column suggested an 8–12 db lower target strength of the deeper group. The results provide acoustic evidence for a smaller body size in the deeper group and the occurrence of an ontogenetic shift in diel migratory behavior of kokanee within Okanagan Lake. Diel comparisons of depth distribution suggested spatial segregation of Mysis and kokanee over much of the diel cycle.

Sign in / Sign up

Export Citation Format

Share Document