Population density comparison of Brachionus angularis (Gosse, 1851) cultured in laboratory at 19°, 21° and 25 °C, fed with bacteria produced in Biofloc system

Abstract

The use of heterotrophic bacteria as only food in rotifers diet to make massive production beakers has been poorly studied, that is why this study used B. angularis cultivated by triplicate in 20 L plastic beakers at temperatures of 19°, 21° and 25 °C, with continuous light and aeration (24 hours), during 60 days. Bacteria was obtained from screened liquid (20 µm) grown in tilapias Biofloc system. Every third day a sample of 500 mL was taken from each beaker and population density was determined. Started experiment, after third day, at 19 °C total organisms died. The maximum density was 18.078 ± 187 (21 °C) and 15,972 ± 157 (25 °C). The reproduction rates were: Ro = 58.16 and 51.49 org.female-1; Tc = 40.50 and 40.7 days respectively and both have r = 0.10. The total density did not exceed 2 org.mL-1. However, heterotrophic bacteria were used as a food to maintain low density rotifer culture or in mixed diets with microalgae.