Document Detail


Phytoplankton food quality determines time windows for successful zooplankton reproductive pulses.
MedLine Citation:
PMID:  17249223     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Recruitment success at the early life stages is a critical process for zooplankton demography. Copepods often dominate the zooplankton in marine coastal zones and are prey of the majority of fish larvae. Hypotheses interpreting variations of copepod recruitment are based on the concepts of "naupliar predation," "nutritional deficiency," and "toxic effect" of diatom diets. Contradictory laboratory and field studies have reached opposite conclusions on the effects of diatoms on copepod reproductive success, blurring our view of marine food-web energy flow from diatoms to higher consumers by means of copepods. Here we report estimates of copepod feeding selectivity and reproduction in response to seasonally changing phytoplankton characteristics measured in a highly productive coastal upwelling area off the coast of central Chile. The variable phytoplankton diversity and changing food quality had a strong and highly significant impact on the feeding selectivity, reproduction, and larval survival of three indigenous copepod species. Seasonal changes in copepod feeding behavior were related to the alternating protozoan-diatom diets, mostly based on dinoflagellates and ciliates during winter and autumn (low highly unsaturated fatty acids [HUFA]/polyunsaturated fatty acids [PUFA] availability), but switched to a diet of centric and chain-forming diatoms (high HUFA/PUFA availability) during the spring/summer upwelling period. Ingestion of diatom cells induced a positive effect on egg production. However, a negative relationship was found between egg hatching success, naupliar survival, and diatom ingestion. Depending on the phytoplankton species, diets had different effects on copepod reproduction and recruitment. In consequence, it seems that the classical marine food web model does not apply to some coastal upwelling systems.
Authors:
Cristian A Vargas; Rubén Escribano; Serge Poulet
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Ecology     Volume:  87     ISSN:  0012-9658     ISO Abbreviation:  Ecology     Publication Date:  2006 Dec 
Date Detail:
Created Date:  2007-01-25     Completed Date:  2007-02-23     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  0043541     Medline TA:  Ecology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2992-9     Citation Subset:  IM    
Affiliation:
Aquatic System Unit, Environmental Sciences Center EULA-Chile, Universidad de Concepción, P.O. Box 160-C, Concepción, Chile. crvargas@udec.cl
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MeSH Terms
Descriptor/Qualifier:
Animals
Biodiversity
Copepoda / physiology*
Diet
Eukaryota / physiology
Feeding Behavior / physiology*
Pacific Ocean
Phytoplankton / physiology*
Reproduction / physiology
Seasons

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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