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Copepod component of zooplankton in a tropical estuary

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Title Copepod component of zooplankton in a tropical estuary
 
Creator Pillai, P. Parameswaran
 
Description 38-46
Copepods constitute the most predominant portion of zooplankton biomass in the Cochin Backwaters throughout the year. Their population largely includes omnivores, although carnivores become abundant during the premonsoon months and herbivores during the monsoon months. Seasonal differences in temperature of the estuary are of the order of 5 °C, while the changes in salinity are considerable. Phytoplankton production does not have a definite seasonal rhythm and shows only two fold increase from the average value in some months. Characteristics of copepod population are investigated by using the diversity indices a, H(s) and ε. An inverse relationship is found between diversity and copepod biomass during the year which indicates that the copepod population is heterogeneous when the biomass is low and homogenous when the biomass is high. The values of a decrease as the copepod number increases, whereas the H(s) and ε values are sensitive to changes in species composition. Species number has little influence on the diversity indices. Similarly zooplankton biomass has no definite relation with the diversity. The relationships between the environmental factors (temperature, salinity and food supply) and the abundance of copepods have been determined from the simple, partial and multiple correlation coefficients. Changes in temperature are linked with those of salinity and these two produce highly unstable conditions in the estuary which induce seasonal variations in the species and in the total abundance of copepods. Food supply seldom acts as a limiting factor in the estuary and does not seem to govern the seasonal abundance of copepods. Six major families of copepods exhibit varying degrees of coexistence among themselves in the environment.
 
Date 2017-01-04T05:38:41Z
2017-01-04T05:38:41Z
1973-06
 
Type Article
 
Identifier 0975-1033 (Online); 0379-5136 (Print)
http://nopr.niscair.res.in/handle/123456789/39633
 
Language en_US
 
Rights CC Attribution-Noncommercial-No Derivative Works 2.5 India
 
Publisher NISCAIR-CSIR, India
 
Source IJMS Vol.02(1) [June 1973]