scholarly journals Growth and diel vertical migration patterns of the toxic dinoflagellate Protoceratium reticulatum in a water column with salinity stratification: the role of bioconvection and light

2015 ◽  
Vol 539 ◽  
pp. 47-64 ◽  
Author(s):  
SR Erga ◽  
CD Olseng ◽  
LH Aarø
2011 ◽  
Vol 59 (3) ◽  
pp. 213-229 ◽  
Author(s):  
Cássia Gôngora Goçalo ◽  
Mario Katsuragawa ◽  
Ilson Carlos Almeida da Silveira

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.


2014 ◽  
Vol 60 (1) ◽  
pp. 252-262 ◽  
Author(s):  
Janet M. Fischer ◽  
Mark H. Olson ◽  
Nora Theodore ◽  
Craig E. Williamson ◽  
Kevin C. Rose ◽  
...  

2007 ◽  
Vol 64 (5) ◽  
pp. 956-962 ◽  
Author(s):  
Rüdiger Voss ◽  
Jörn O. Schmidt ◽  
Dietrich Schnack

Abstract Voss, R., Schmidt, J. O., and Schnack, D. 2007. Vertical distribution of Baltic sprat larvae: changes in patterns of diel migration? – ICES Journal of Marine Science, 64: 956–962. Ontogenetic and diurnal vertical migration patterns of Baltic sprat larvae were investigated for the periods 1989–1990 and 1998–2002. Comparison of the results led to the hypothesis that the diel vertical migration behaviour of sprat larvae >10 mm has changed. In 1989 and 1990, sprat larvae migrated to the surface at night, whereas they stayed 30–50 m deep by day. From 1998 to 2002, sprat larvae showed no signs of diel vertical migration, remaining in warmer, near-surface water by day and night. This behavioural change coincided with a more general change in the Baltic ecosystem, i.e. an increase in near-surface temperature and a general increase in abundance of the major prey organism (Acartia spp.) of Baltic sprat larvae, with more pronounced aggregation in surface waters.


Author(s):  
RODRIGO RAMOS-JILIBERTO ◽  
JOSÉ L. CARVAJAL ◽  
MAURICIO CARTER ◽  
LUIS R. ZÚÑIGA

1984 ◽  
Vol 41 (12) ◽  
pp. 1837-1843 ◽  
Author(s):  
S. A. Arkett

The hydromedusan Polyorchis penicillatus makes a small amplitude diel vertical migration. During the day, over 85% of the individuals were observed within 1 m of the bottom, while at night, medusae diffused several metres up into the water column. This movement occurred concomitantly with the emergence of many of the major taxa of demersal Zooplankton whose activity was quantified by emergence traps. Food boli contents collected from Polyorchis showed some selectivity for large, fast-moving demersal plankters and low capture and utilization of invertebrate larvae. Diel shifts in feeding behavior and water column position enable Polyorchis to feed efficiently on high densities of demersal plankters at all times. Medusae may be exempt from migration constraints imposed by visual predators and are thus able to move into areas of high prey density to supply energetic requirements. Hydromedusae, such as Polyorchis, are shown to utilize a variety of factors, such as tentacle position and swimming speed, in an "ambush" strategy to optimize prey encounters.


2010 ◽  
Vol 67 (7) ◽  
pp. 1436-1443 ◽  
Author(s):  
Elizabeth K. Shea ◽  
Michael Vecchione

Abstract Shea, E. K., and Vecchione, M. 2010. Ontogenic changes in diel vertical migration patterns compared with known allometric changes in three mesopelagic squid species suggest an expanded definition of a paralarva. – ICES Journal of Marine Science, 67: 1436–1443. Planktonic and newly hatched cephalopods are routinely called paralarvae. Currently, the onset of diel vertical migration (DVM) marks the end of the paralarval phase, although changes in ontogenic growth trajectories may also be used. Patterns of DVM are reported for the first time for three poorly understood mesopelagic squid species. Discrete-depth samples taken during the Amsterdam Mid North Atlantic Plankton Expeditions (AMNAPE) of 1980–1983 are used to examine the timing of ecological and morphological changes in Chtenopteryx sicula, Mastigoteuthis magna, and Brachioteuthis sp. 3. DVM patterns are species-specific, and ontogenic changes in DVM coincide with allometric changes in the arm, fin, and funnel characters of C. sicula at 7 mm mantle length. Mastigoteuthis magna is not concentrated in the upper 250 m of the water column during the day, and no clear DVM pattern is found in Brachioteuthis sp. 3, meaning that the endpoint of the paralarval phase cannot be defined ecologically in these species. Other ecological transformations, e.g. changes in prey-capture ability, are therefore explored as alternatives to DVM. The pad-shaped club and long neck are proposed as visual markers of the end of the paralarval phase of C. sicula and Brachioteuthis sp. 3, respectively.


1991 ◽  
Vol 48 (1) ◽  
pp. 67-72 ◽  
Author(s):  
David A. Levy

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.


2008 ◽  
Vol 59 (8) ◽  
pp. 671 ◽  
Author(s):  
D. J. Vance ◽  
R. C. Pendrey

Knowledge of the vertical migration behaviour of postlarval penaeid prawns is important in understanding postlarval migration from offshore spawning grounds to estuarine nursery areas. We sampled throughout several 24-h periods in two estuaries in Australia to assess the distribution of postlarvae in the water column. We used four trawl nets: one net in the top 0.5 m of the water column and three nets one above the other, from the seabed to 0.72 m above the seabed. Penaeus plebejus was abundant in catches in the Nerang River, southern Queensland, while Penaeus semisulcatus, Penaeus esculentus and Penaeus merguiensis were caught in the Embley River, northern Queensland. For all species, the highest catches at the surface were on night flood tides. Many postlarvae in the Embley River were caught in nets above the seabed on ebb tides, suggesting that net migration patterns cannot be determined simply by sampling surface waters. The vertical distribution of penaeid postlarvae is determined primarily by tide and day/night; however, water turbidity and cloud cover, factors that reduce light at the seabed, are also likely to be important. All these aspects of postlarval behaviour should be included in hydrodynamic models of larval advection from spawning grounds to inshore nursery areas.


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