Use of diluted acids and scrub pads in the mass culture of the freshwater rotifer Brachionus calyciflorus

• Published in: Aquaculture, Aquarium, Conservation & Legislation Vol. 12; no. 4; pp. 1156 - 1162
• Main Authors: Torres, Gustavo A, Imués, Marco A, Acosta, Jhon E, Sanguino, Wilmer R, Chapman, Frank A
• Format: Journal Article
• Language: English
• Published: Cluj-Napoca Bioflux SRL 01.08.2019
• Subjects: Acids; Aeration; Aeration tanks; Algae; Ammonia; Aquaculture; Automation; Brachionus calyciflorus; Cleaning; Contaminants; Culture; Culture media; Darkness; Dilution; Experiments; Fish; Fisheries; Fluorescence; Freshwater; Freshwater fish; Hydrochloric acid; Inland water environment; Laboratories; Live feeds; Marine invertebrates; Mass culture; Microorganisms; Organic loading; Phytoplankton; Polypropylene; Rotifera; Scrub; Temperature; Variance analysis; Water quality; Water temperature; Zebrafish; Zoology; Colombia; India
• ISSN: 1844-8143; 1844-9166

The rotifer Brachionus calyciflorus is one of the principal live feed organisms cultured for the larval feeding of freshwater fish. In this study the addition of dilute hydrochloric acid (1%) and the commercial Acid Buffer™ (5%) from Seachem Laboratories were investigated to control the toxic levels of unionized ammonia in batch cultures of this rotifer species. The acids were added manually to the culture, three times per day to adjust to a neutral pH the culture medium. In a second experiment, the use of household cleaning scrub pads to manage the high organic load generated during the rotifer culture was also investigated. The rotifers for the experiments were placed in 400 mL polypropylene culture vessels, supplied with aeration, and the water temperature was maintained at 28°C. The rotifers were fed with the microalgae Scenedesmus sp. and exposed daily to 12-hour periods of indirect fluorescent illumination (< 300 lux), and darkness. Both experiments were run in triplicate and the data analyzed with ANOVA and Tukey tests (p = 0.05). The results indicated the manual addition of either one of the diluted acids to the experimental rotifer cultures was enough to prevent the rise of unionized ammonia levels in the culture water, and favored increased population densities of the rotifers from an overall of 1,094±67 rotifers mL-1 in the culture medium, at the beginning of the trial, to above 2,000 rotifers mL-1 at the third day of the trial. The mean rotifer densities significantly increased from approximately 445±6 to 2,679±64 rotifers mL-1 at the fifth day of the trial when the scrub pads were used; which successfully trapped debris and living contaminants in the culture system. The methodology described in the study is inexpensive and easily implemented; and achieved rotifer densities significantly above those reported in the literature for the same species (e.g., 50 to 685 rotifers mL-1 in culture).