Rotifer Culture Abstracts

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Use of GABA to enhance rotifer reproduction in enrichment culture
W G Gallardo, A Hagiwara & T W Snell

Abstract

Gamma-aminobutyric acid (GABA) has been shown to enhance the reproduction of the rotifer Brachionus plicatilis Muller in stressful culture conditions. During the enrichment of rotifers for feeding to marine fish larvae, they are usually stressed as a result of exposure to different marine oils and high population densities. This typically results in decreased rotifer survival, reproduction and swimming activity. In the present study, we used GABA to increase rotifer reproduction and the swimming activity of rotifers in enrichment cultures. GABA treatment 24 h before high density enrichment enhanced reproduction during enrichment culture, but not when carried
out simultaneously with enrichment. Swimming activity was not significantly affected by GABA treatment 24 h before or simultaneously with nutrient enrichment.

Extracted from:
Aquaculture Research
Volume 32 Page 243 - March 2001
doi:10.1046/j.1365-2109.2001.00553.x
Volume 32 Issue 3

Abstract Source: Blackwell-Synergy
http://www.blackwell-synergy.com/doi...2rotifer%22%29

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Improved performance of an intensive rotifer culture system by using a nitrifying inoculum (ABIL)

G Rombaut, R Grommen, Q Zizhong, V Vanhoof, G Suantika, P Dhert, P Sorgeloos & , W Verstraete

Abstract

A dense nitrifying culture (ABIL) has been examined for its capacity to
stimulate rotifer growth in a labscale culture system. The nitrifiers were applied in different ways. When ABIL was added directly to rotifer batch cultures, it gave rise to significantly higher population densities (factor 1.5–2.5 higher, P < 0.05). The nitrifiers were subsequently examined for their capacity to enhance the start-up of bioreactors, commonly installed in aquaculture rearing tanks. Of the different carrier materials used in these bioreactors, i.e. CaCO3, gravel and a PVC matrix (Bionet), CaCO3 gave by far the best results. In a third set of experiments, effectively nitrifying bioreactor systems were connected to rotifer culture tanks and operated over a period of up to 10 days. It was demonstrated that the ABIL inoculated
CaCO3-based bioreactor allowed excellent rotifer growth reaching rotifer densities up to 5500 rotifers per mL. Moreover, a new system in which the ABIL culture was recirculated through hollow fibres was developed and demonstrated to be effective for supporting rotifer growth up to 3500 rotifers per mL. Overall, the use of the dense nitrifying culture either in seed batch cultures, conventional bioreactors or hollow fibre bioreactor systems in support of rotifer cultures was demonstrated to be effective for improving the water quality and the rotifer growth.


Extracted from:
Aquaculture Research
Volume 34 Page 165 - January 2003
doi:10.1046/j.1365-2109.2003.00798.x
Volume 34 Issue 2

Abstract Source
http://www.blackwell-synergy.com/doi...2rotifer%22%29

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Growth, filtration and ingestion rate of the rotifer Brachionus plicatilis fed with large (Asteromonas gracilis) and small (Chlorella sp.) celled algal species.

George N. Hotos

Abstract

The rotifer Brachionus plicatilis was fed in experimental conditions with a small
celled (2–5 μm) Chlorella sp. and a large celled (16–22 μm) Asteromonas gracilis algae. The specific growth rate (SGR) of rotifers fed Asteromonas (maximum 0.79) was statistically higher than that for rotifers fed Chlorella (maximium 0.61). The filtration and ingestion rates using different rotifer and algal densities exhibited certain maxima depending on the species, the cell density and the condition of the rotifers. The filtration rate was higher with Asteromonas and, although ingestion rate was lower than with Chlorella, the ingestion in terms of cell volume was 10-fold higher. It seems that B. plicatilis ingests the larger cell diameter algal species more efficiently than the smaller species that is usually used for its mass culture.

Extracted from:
Aquaculture Research
Volume 34 Page 793 - August 2003
doi:10.1046/j.1365-2109.2003.00868.x
Volume 34 Issue 10


Abstract Source
http://www.blackwell-synergy.com/doi...2rotifer%22%29

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Title: Trial Finds Microalgae Paste Suitable for Rotifer Nutrition
Submitted to: Global Aquaculture Advocate
Publication Type: Trade Journal
Publication Acceptance Date: May 1, 2002
Publication Date: August 1, 2002
Citation: Ludwig, G.M., Pfeiffer, T.J. Trial Finds Microalgae Paste Suitable for Rotifer Nutrition. Global Aquaculture Advocate. 2002. V.5 (4). P.22-23.

Interpretive Summary: Most commercially cultured fish require zooplankton, particularly rotifers when they are fry. Rotifers are usually difficult to culture. A rotifer culture system was developed that could be easily used by fish culterists. Four tanks were filled with brackish water (25-30 ppt) and a starter population of rotifers. Temperatures were kept between 25 and 30°C. A paste composed of concentrated microalgae was diluted and then constantly fed to the rotifers by using a peristaltic pump. When the rotifer population reached 1500/ml a third of the culture was harvested daily. The water was replenished daily. The system was kept running for three weeks and 70% of the days the culture reached the desired concentration.

Technical Abstract: The primary food of many larval fish is zooplankton, often rotifers. Brachionus plicatilis, a brackish-water rotifer is often cultured to feed to the fry of many commercially grown fish. A culture system to efficiently produce large quantities of this rotifer was developed. The system is composed of four 60-L conical polyethylene tanks filled to 45 L. Water temperatures were kept between 25 and 30°C and salinity at 25-30 ppt. A sponge filter removed waste particulate matter. Commercially available Nannochloropsis algal paste was continuously pumped to the system to feed the rotifers at the rate of 75,000 algal cells/rotifer/day. Total daily amounts of paste depended upon rotifer concentrations that were determined daily. The algal paste was diluted with salt water to 2.4 L, kept in an electric cooler and constantly transferred to the culture chamber with a peristaltic pump at 100 ml/hr. A population of rotifers at 500 to 1500 rotifers/ml was maintained for 21 days. Fifteen liters per day was harvested when the population was 1500/ml or greater. The four tanks were at the 1500 rotifers/ml for 64-73% of the time. An estimated 20-135 million rotifers (average 75 million) per day were harvested. The cost for salt and algal paste was estimated at $0.23-0.26/million rotifers harvested.

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Enhancement of rotifer (Brachionus plicatilis) growth by using terrestrial lactic acid bacteria.
M. Planas, J.A. Vázquez, J. Marqués, R. Pérez-Lomba, M.P. González and M. Murado
Aquaculture
Volume 240, Issues 1-4 , 27 October 2004, Pages 313-329


Abstract

One of the pathways for the entry of bacteria, both pathogenic and probiotic, into the larvae of fish hatcheries is via live prey. As a preventive measure against infections, live prey may be cultured, supplementing the food with probiotics. Some lactic acid bacteria (LAB) have been successfully used in the larviculture. In this study, the nutritional effect of seven terrestrial LAB has been studied regarding the growth of the rotifer Brachionus plicatilis. The cultures were carried out without partial renewal of the culture medium, feeding the rotifers on baker's yeast and adding some of the species of bacteria. In all cases, the addition of the bacteria increased both the specific maximum growth rate and the maximum density obtainable in the cultures. However, the best results were obtained with the addition of Lactococcus casei ssp. casei, Pediococcus acidilactici, or Lactobacillus lactis spp lactis. The rates of growth obtained with the individual or joint addition of these three bacteria were 8–13 times greater than those obtained with the control cultures after 4–5 days' culture. In this study, a series of kinetic models has been applied (logistic modified—Gompertz, logistic–logistic, and generalised logistic) which describes the experimental data, obtaining a set of parameters of biological significance which facilitate the optimisation of the use of these bacterial strains in the mass production of rotifers.

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