Parthenogenetic reproduction of Diaphanosoma celebensis (Crustacea : Cladocera). Effect of algae and algal density on survival, growth, life span andneonate production

The cladoceran Diaphanosoma celebensis Stingelin is reported on for the fir st time from Indian waters (Mandovi estuary, Goal. Amictic females were mai ntained in the laboratory (temperature 24 +/- 1 degrees C and salinity 17 p su) for three successive generations in order to follow the parthenogenetic reproductive behaviour,, growth, survival and neonate production. The mean life span and body length of adult females in the three generations showed some variations and ranged from 9 to 12.5 d and 842 to 932 mu m, respectiv ely. The mean length of the neonates produced also varied (283 to 446 mu m) in the three generations. Cladoceran preference for three phytoplankton fo od sources, i.e. Isochrysis sis galbana (Parke), Chaetoceros calcitrans (Pa ulsen) and Tetraselmis gracilis (Kylin), was determined. Growth was faster in the initial stage with all three diets but slowed down in later life. In creased food concentrations resulted in higher neonate production but reduc ed the life span of females. However, long-term feeding experiments reveale d that the percentage survival was high with I. galbana and low with C. cal citrans.