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פותח על ידי קלירמאש פתרונות בע"מ -
Fish larvae: Zooplankton relationships in microcosm simulations of earthen nursery ponds. II. Brackish water system
Year:
2006
Source of publication :
Aquaculture International
Authors :
הרפז, שנאן
;
.
מילשטיין, אנה
;
.
Volume :
14
Co-Authors:
Milstein, A., Agricultural Research Organization, Fish and Aquaculture Research Station, M.P. Hof HaCarmel 30820, Israel
Valdenberg, A., Kibbutz Maagan Michael, DN Manashe, Israel
Harpaz, S., Department of Aquaculture, Agricultural Research Organization, Bet Dagan 50250, Israel
Facilitators :
From page:
431
To page:
442
(
Total pages:
12
)
Abstract:
A simulation of the effects of predation intensity on zooplankton composition in brackish water nursery ponds was carried out in order to address the problem that commercial fish nurseries encounter in obtaining enough zooplankton of adequate species composition and size when fish larvae start to feed. The experimental system consisted of twelve 130 l containers with treatments of four densities (0, 1, 2, or 4 larvae l-1) of common carp (Cyprinus carpio L.), stocked on the 6th day after filling the containers. Zooplankton-environment relationships were explored using factor analysis. Factor analysis allowed identifying several groups of zooplankters that responded in different ways to fish larvae predation pressure. The first factor represented a general measurement of rotifer abundance, and the second identified the direct effect of size-selective fish predation. Since no rotifers were present in the filling water, all these species were autochthonous populations that hatched from resting forms in the sediment and reproduced. In the absence of fish predation, this led to a steep rotifer increase. Fish predation started when the rotifer concentration was just starting to increase and their direct predation reduced and delayed the rotifer abundance peak. This effect increased with the increase in fish larvae density. Estimations of rotifer consumption by fish larvae in this experiment were higher than similar calculations from data of the literature, which led us to test the hypothesis that factors other than direct predation were affecting rotifer population dynamics. The mechanisms involved in rotifer population regulation are discussed. It was concluded that in commercial nurseries, increased larvae production can be achieved by keeping the larvae density at an intermediate level and stocking fish to match the increasing phase of the rotifer peak. Under reasonable larvae density (up to 2 l-1) it seems that the direct predation effect of fish larvae on rotifer dynamics is minor, compared to fish induced self regulation. © Springer Science+Business Media, Inc. 2006.
Note:
Related Files :
Common carp
Cyprinus carpio
Ecology
fish
fish culture
Management
nursery ground
population dynamics
predation
עוד תגיות
תוכן קשור
More details
DOI :
10.1007/s10499-006-9046-1
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
24910
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:11
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Scientific Publication
Fish larvae: Zooplankton relationships in microcosm simulations of earthen nursery ponds. II. Brackish water system
14
Milstein, A., Agricultural Research Organization, Fish and Aquaculture Research Station, M.P. Hof HaCarmel 30820, Israel
Valdenberg, A., Kibbutz Maagan Michael, DN Manashe, Israel
Harpaz, S., Department of Aquaculture, Agricultural Research Organization, Bet Dagan 50250, Israel
Fish larvae: Zooplankton relationships in microcosm simulations of earthen nursery ponds. II. Brackish water system
A simulation of the effects of predation intensity on zooplankton composition in brackish water nursery ponds was carried out in order to address the problem that commercial fish nurseries encounter in obtaining enough zooplankton of adequate species composition and size when fish larvae start to feed. The experimental system consisted of twelve 130 l containers with treatments of four densities (0, 1, 2, or 4 larvae l-1) of common carp (Cyprinus carpio L.), stocked on the 6th day after filling the containers. Zooplankton-environment relationships were explored using factor analysis. Factor analysis allowed identifying several groups of zooplankters that responded in different ways to fish larvae predation pressure. The first factor represented a general measurement of rotifer abundance, and the second identified the direct effect of size-selective fish predation. Since no rotifers were present in the filling water, all these species were autochthonous populations that hatched from resting forms in the sediment and reproduced. In the absence of fish predation, this led to a steep rotifer increase. Fish predation started when the rotifer concentration was just starting to increase and their direct predation reduced and delayed the rotifer abundance peak. This effect increased with the increase in fish larvae density. Estimations of rotifer consumption by fish larvae in this experiment were higher than similar calculations from data of the literature, which led us to test the hypothesis that factors other than direct predation were affecting rotifer population dynamics. The mechanisms involved in rotifer population regulation are discussed. It was concluded that in commercial nurseries, increased larvae production can be achieved by keeping the larvae density at an intermediate level and stocking fish to match the increasing phase of the rotifer peak. Under reasonable larvae density (up to 2 l-1) it seems that the direct predation effect of fish larvae on rotifer dynamics is minor, compared to fish induced self regulation. © Springer Science+Business Media, Inc. 2006.
Scientific Publication
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