ISSN:
1573-5117
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Seasonal abundance and the pattern of fluctuations in the zooplankton of a tropical fish pond has been studied at weekly intervals for a period of two years from September 1960 to August 1962. Except for a group of ciliates, protozoa were found only in limited numbers. Coleps, Tintinnus and Difflugia were recorded during both the years, whereas Arcella and Codonella were collected in the first year only. Other members as Centropyxis, Didinium, Paradileptus, Stentor and Bursaria were seen occasionally as few individuals. The total numbers of protozoa showed their peak from January to April and the prevailing phytoplankton abundance and temperature conditions are suggested as probable causative factors. More than thirty species of rotifers were recorded during this study, although many of them were only in limited numbers. Loricate forms showed their maximum density in summer months only, when total alkalinity values were also high. Nonloricate forms were found during September, October and December to February. The effect of temperature, total alkalinity and phytoplankton on these populations have been discussed. Five species of Copepoda were recorded. The most dominant copepod Mesocyclops hyalinus was present almost throughout the year and its fluctuation pattern closely resembled that of the copepodids and the nauplii. Definite peaks in naupliar populations were probably indicative of periods of active reproduction. Among the five species of cladocera, Diaphanosoma brachyurum was present during certain months only, in both the years. Moina brachiata was present during the first year only. The total abundance of these microcrustacea showed direct relationship with phytoplankton production. The importance of these investigations in fish cultural practices is suggested.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00179538
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