Larval feeding behaviour of angel fish Pterophyllum scalare (Cichlidae) fed copepod Eucyclops serrulatus and cladoceran Ceriodaphnia quadrangula
Abstract: Three different live diets, Eucyclops serrulatus, Ceriodaphnia quadrangula and equal combination of E. serrulatus copepodid and C. quadrangula, were offered to angelfish (Pterophyllum scalare) larvae viz 1-week, 2-week and 3-week old at prey densities of 2, 5 and 10 individuals mL1 . Results showed that 1-week-old P. scalare larvae consumed E. serrulatus copepodid at a rate of 31.3–56.7 ind. h1 , C. quadrangula at 8.0–12.0 ind. h1 , and mixture of E. serrulatus and C. quadrangula at 20.7–40.7 ind. h1 . For 2-week- and 3-week-old larvae, consumption rate increased accordingly. The electivity indices (E) of P. scalare (1-week-old larvae) for E. serrulatus copepodid were +0.18, +0.23 and +0.22 at prey densities of 2, 5 and 10 ind. mL1 respectively. Tendency towards E. serrulatus copepodid consumption reduced by aging P. scalare as indicated by the E values for 2- and 3-week-old larvae. However, growth and survival of P. scalare larvae was greatest when fed on combination of copepod E. serrulatus and C. quadrangula.
Keywords: Ingestion rate, Pterophyllum scalare, Eucyclops serrulatus, Ceriodaphnia quadrangula