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

Abstract

The cladoceran Diaphanosoma celebensis Stingelin is reported on for the first time from Indian waters (Mandovi Estuary, Goa). Amictic females were maintained in the laboratory (temperature 24 plus or minus 1 degrees C and salinity 17 psu) 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, respectively. The mean length of the neonates produced also varied (283 to 446 mu m) in the three generations. Cladoceran preference for three phytoplankton food sources, i.e. Isochrysis galbana (Parke), Chaetoceros calcitrans (Paulsen) and Tetraselmis gracilis (Kylin), was determined. Growth was faster in the initial stage with all three diets but slowed down in later life. Increased food concentrations resulted in higher neonate production but reduced the life span of females. However, long-term feeding experiments revealed that the percentage survival was high with I. galbana and low with C. calcitrans