DISTRIBUTION AND BIOLOGY OF MARINE CLADOCERANS IN THE COASTAL WATERS OF SOUTHERN CHINA

Geographical and seasonal distributions of marine cladocerans in the coastal waters of southern China were studied. Penilia avirostris was the most common species, followed by Evadne tergestina and Podon schmackeri. P. avirostris and E. tergestina were most common during summer. P schmackeri, found only in a small bay northeast of Hong Kong, showed no clear seasonal pattern of occurrence. P. avirostris and E. tergestina were found at temperatures ranging from 16-32 degrees C and salinity ranging from 7.3-37.2 parts per thousand. P. schmackeri was restricted to a temperature range of 17-29 degrees C and a salinity range of 31.0-37.2 parts per thousand. No significant relationships between marine cladoceran abundance and chlorophyll a concentration were found in samples taken from Tolo Harbour. Parthenogenetic brood size of P avirostris and E. tergestina ranged from 1 to 14, while P. schmackeri was found to carry up to 19 embryos per brood. No geographical trend in fecundity patterns was observed. No correlation was found between body length and brood size. The occurrence of females with resting eggs was rare.