Zooplankton of Kanchanaburi Province, Thailand

Abstract

The freshwater zooplankton of 5 types of water body in the western part of Thailand was studied for twelve months. Twenty-one species of Protozoa, eighty-eight species of Rotifera, twenty-eight species of Cladocera, two species of Calanoida and two species of Cyclopoida were found in samples collected monthly in 1998. In general, Rotifera dominated in all water-bodies, although fluctuations occurred during the year. Samples from the reservoir heavily vegetated yield the highest number of species. The following species are common Thai zooplankton: Arcella bathysoma, A. vulgaris, Centropyxis aculeata, Difflugia lebes, D. urceolata, Euglypha filifera, Anuraeopsis fissa, Brachionus angularis, B. falcatus, Filinia longiseta, Keratella cochlearis, K. tropica, Lecane bulla, L. papuana, Polyarhra vulgaris, Trichocerca similis, Ceriodaphnia cornuta, Bosminopsis deitersi, Diaphanosoma excisum and moina micrura. A tropical rare species, Daphnia lumholzi, was found in rivers, reservoirs and man-made lake in this study. Copepoda was a minor component in the study area where Thermocyclops crassus was common throughout the year. One calanoid copepod, Phyllodiaptomus sasikumari found in a richfield is the first record in Thailand. Seasonal variation of species composition might not be so pronounced, however number of species at most sampling locations increased during wet season.