Population growth of Lepadella patella (O. F. Müller, 1786) at different algal (Chlorella vulgaris) densities and in association with Philodina roseola Ehrenberg, 1832

Abstract

Population growth of Lepadella patella was studied using Chlorella as the sole food at five concentrations ranging from 0.25 × 10⁶ to 4.0 × 10⁶ cells ml⁻¹ at 25 °C for 22 days. The population densities increased with increasing algal concentration up to 1.0 × 10⁶ cells ml⁻¹. The population growth of L. patella was lower at algal concentration of 2.0 × 10⁶ cells ml⁻¹ and above. In a separate experiment, we tested the influence of the bdelloid rotifer Philodina roseola on the population growth of L. patella at different ratios of initial inoculation densities using 1.0 × 10⁶ cells ml⁻¹ of Chlorella at 28 °C. Despite lower initial inoculation densities compared with those in the controls, both L. patella and P. roseola showed higher peak abundances when grown together. The maximum peak abundance values recorded for L. patella and P. roseola were 830 and 230 ind. ml⁻¹, respectively, at an inoculation ratio of 1:1.