The Vertical Distribution of the Siphonophores Collected During the SOND Cruise, 1965

In many of the more general studies on marine zooplankton the part played by siphonophores is frequently ignored or only given a cursory mention. However, their ecological importance is far from insignificant. In this context we are indebted to the late Mr A. K. Totton whose publications have done much to draw attention to the siphonophores and the part which they play in the zooplankton community. His synopsis of the siphonophores (Totton, 1965) is a masterly work from which any student of this fascinating group can derive much benefit.

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Seasonal vertical distribution and diel migration of zooplankton in a temperate stratified lake

Biologia ◽

10.2478/s11756-011-0023-4 ◽

2011 ◽

Vol 66 (2) ◽

Cited By ~ 10

Author(s):

Evangelia Doulka ◽

George Kehayias

Keyword(s):

Vertical Distribution ◽

Zooplankton Community ◽

Abiotic Factor ◽

High Concentration ◽

Diel Migration ◽

Four Seasons ◽

Diel Vertical Migrations ◽

Vertical Segregation ◽

And Migration ◽

The Vertical Distribution

AbstractThe investigation of the vertical distribution of the zooplankton community in the temperate Lake Trichonis during four seasons in 2005, showed the existence of vertical segregation among species, ontogenetic stages and sexes within and between the major groups. In each season, the two or three more abundant rotifer species distributed at separate depth layers, while this feature was maintained during the entire 24 h period, since no diel vertical migrations (DVM) were performed. In contrast, the crustacean community, comprised mainly by the calanoid copepod Eudiaptomus drieschi and the cladoceran Diaphanosoma orghidani, showed various patterns of DVM, being more pronounced in spring and summer. Females of E. drieschi distributed deeper than males, while the copepod nauplii were found mainly in the surface layer in all four seasons. Temperature was the most important abiotic factor affecting directly and indirectly the vertical distribution and migration of various species. During stratification, the metalimnion was the most productive layer in Lake Trichonis, having maximum values of dissolved oxygen and low transparency due to high concentration of organic matter and phytoplankton. The DVM patterns of the crustaceans indicate that the metalimnion acts probably as a daylight refuge against predation by Atherina boyeri, which is the dominant planktivorous fish in the lake.

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A marine zooplankton community vertically structured by light across diel to interannual timescales

Biology Letters ◽

10.1098/rsbl.2020.0810 ◽

2021 ◽

Vol 17 (2) ◽

pp. 20200810

Author(s):

Laura Hobbs ◽

Neil S. Banas ◽

Jonathan H. Cohen ◽

Finlo R. Cottier ◽

Jørgen Berge ◽

...

Keyword(s):

Predation Risk ◽

Zooplankton Community ◽

Foraging Strategy ◽

High Arctic ◽

Visual Predation ◽

Marine Zooplankton ◽

Arctic Fjord ◽

Change Impact ◽

Extreme Seasonality ◽

The Vertical Distribution

The predation risk of many aquatic taxa is dominated by visually searching predators, commonly a function of ambient light. Several studies propose that changes in visual predation will become a major climate-change impact on polar marine ecosystems. The High Arctic experiences extreme seasonality in the light environment, from 24 h light to 24 h darkness, and therefore provides a natural laboratory for studying light and predation risk over diel to seasonal timescales. Here, we show that zooplankton (observed using acoustics) in an Arctic fjord position themselves vertically in relation to light. A single isolume (depth-varying line of constant light intensity, the value of which is set at the lower limit of photobehaviour reponses of Calanus spp. and krill) forms a ceiling on zooplankton distribution. The vertical distribution is structured by light across timescales, from the deepening of zooplankton populations at midday as the sun rises in spring, to the depth to which zooplankton ascend to feed during diel vertical migration. These results suggest that zooplankton might already follow a foraging strategy that will keep visual predation risk roughly constant under changing light conditions, such as those caused by the reduction of sea ice, but likely with energetic costs such as lost feeding opportunities as a result of altered habitat use.

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Preliminary studies on the vertical distribution of size-fractions in the zooplankton community in Lindåspollene, western Norway

Sarsia ◽

10.1080/00364827.1983.10420558 ◽

1983 ◽

Vol 68 (1) ◽

pp. 65-79 ◽

Cited By ~ 18

Author(s):

Ulf Lie ◽

Thorolf Magnesen ◽

Björn Tunberg ◽

Dag Aksnes

Keyword(s):

Vertical Distribution ◽

Zooplankton Community ◽

Size Fractions ◽

Western Norway ◽

The Vertical Distribution

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Aspects on the seasonal dynamics and the vertical distribution of the crustacean zooplankton community and the Dreissena polymorpha larvae in Lake Trichonis

Mediterranean Marine Science ◽

10.12681/mms.206 ◽

2004 ◽

Vol 5 (1) ◽

pp. 19 ◽

Cited By ~ 6

Author(s):

G. KEHAYIAS ◽

E. MICHALOUDI ◽

A. BEXI

Keyword(s):

Vertical Distribution ◽

Seasonal Dynamics ◽

Dreissena Polymorpha ◽

Zooplankton Community ◽

Vertical Axis ◽

Crustacean Zooplankton ◽

Eutrophic Lakes ◽

Main Factors ◽

Daphnia Cucullata ◽

The Vertical Distribution

In Lake Trichonis 9 crustacea species and the molluscan larvae of Dreissena polymorpha were recorded during four seasonal samplings from summer 2002 to spring 2003. Mean integrated values of crustacea abundance ranged from 4.5 to 12.9 ind/L and were mainly dominated by the calanoida Eudiaptomus drieschi. The abundance values recorded, as well as the seasonal dynamics, followed the monoacmic pattern of oligotrophic lakes. However, the presence of Daphnia cucullata, a typical representative of eutrophic lakes, the decrease of the calanoida participation in the crustacea community and the succession in the cladocera community, could probably indicate a tendency towards a change of the trophic condition of Lake Trichonis.Along the vertical axis the maximum abundance of the zooplankton community was recorded in the surface 0-10 m. Mollusca larvae were present in all seasons and their highest abundance was recorded in the surface layer 0-10 m. Temperature, competition and predation seemed to be the main factors regulating vertical distribution.

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