their role and production requirements Rotifers their role and production requirements Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Reproduction Mass production Size Mobility Tolerance Bio-encapsulation Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Life cycle B. plicatilis Live food aquaculture training course www.aquatrain.org

Rotifer production – optimal culture and enrichment conditions Tank: Any Size/Shape (2-6 m3) Temp.: 25-27 °C (Preheated Water/Heat Exchange) Salinity: 18-25 ppt Oxygen: 5-7 ppm (Pure Oxygen) pH: 7.5-8.5 NH3/NH4+: < 10 mg/l NH3: < 1 mg/l Water: Filtered (1 m), UV, Chlorinated/Neutralized Aeration - Reasonably Strong - Airstones Illumination: Low Light Conditions Floc traps Batch Culture: 3-5 days There are several critical conditions that have to be met in order to guarantee rotifer production and failure to achieve this can lead to stock crashes which without alternative food sources for the larvae can have serious impact on juvenile production. Live food aquaculture training course www.aquatrain.org

Rotifer production in 3m3 tanks The second link of the live food chain is the rotifer. Here we see a typical production facility operating on a 4 day batch culture cycle. A hatchery producing 5 million juveniles per year will require approximately 2-4 billion rotifers per day for consumption by fish during the larval rearing periods. Live food aquaculture training course www.aquatrain.org

Low density rotifer culture Sea bream   General assumptions 1) Av. daily rotifer consumption/m3 larval volume (M) 10 2) Rotifer production volume/100M daily production (m3) 1,5 3) Period of rotifer feeding (days) 20 4) Culture Selco needed per 100M rotifers produced (kg) 0,2 5) Culture Selco price (drs/kg) 11234 Annual production target (2g juveniles) No of larval batches 5 Initial larval rearing vol (m3) 62 123 185 308 Daily rotifer requirement (M) 615 1.231 1.846 3.077 Rotifer production volume (m3) 9 18 28 46 No of 2.8m3 tanks needed 3 7 16 No of 4m3 tanks required Total rotifer production volume (m3) 8 45 Total Culture Selco requirement (kg) 246 369 Requirements 2.000.000 4.000.000 6.000.000 10.000.000 Cost of Culture Selco (Mdrs/yr) 1,38 2,77 4,15 6,91 Live food aquaculture training course www.aquatrain.org

Rotifer culture using algae excellent results with algae but expensive time consuming (culture of algae + counting) availability of algae quality of the rotifers dependent on quality of the algae Live food aquaculture training course www.aquatrain.org

Rotifer culture using algae and yeast variable results in rotifer survival depending on the quality of algae and freshness of the yeast unexpected mortalities (total crashes) due to lack of standardisation variability in rotifer quality (nutrition, microbiology) Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Batch culture of rotifers on algae and yeast Culture period 6-10 days f e d i n g harvest drain culture water Re-inoculation Live food aquaculture training course www.aquatrain.org

Medium density rotifer culture Sea bream   General assumptions 1) Av. daily rotifer consumption/m3 larval volume (M) 10 2) Rotifer production volume/100M daily production (m3) 0,4 3) Period of rotifer feeding (days) 20 4) Culture Selco 3000 needed per 100M rotifers produced (kg) 0,20 5) Culture Selco price (drs/kg) Annual production target (2g juveniles) No of larval batches 5 Initial larval rearing vol (m3) 62 123 185 308 Daily rotifer requirement (M) 615 1.231 1.846 3.077 Rotifer production volume (m3) 2 7 12 No of 2.8m3 tanks needed 3 16 No of 4m3 tanks required Total rotifer production volume (m3) 8 28 45 Total Culture Selco 3000 requirement (kg) 246 369 Requirements 2.000.000 4.000.000 6.000.000 10.000.000 Cost of Culture Selco (Mdrs/yr) 0,00 Live food aquaculture training course www.aquatrain.org

Rotifer growth comparison CS v’s CS3000 Here we can see the typical growth curve of Culture selco 3000 against it predecessor the simple culture selco. Live food aquaculture training course www.aquatrain.org

Specific Growth Rate in MD batch culture Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Method of determining rotifer growth and condition– mean specific growth rates SGR = ln (Final Number)-ln (Initial number) No. of days of culture ln = natural log Useful for:- Following feeding experiments Quantitatively assessing culture stability Live food aquaculture training course www.aquatrain.org

Rotifer production methodologies Culture Selco 3000 and O2 Rotifer production methodologies have improved over the years from an algae and yeast based diet which can if not carefully used give unpredictable results to improved culture diets which were less dependant upon algae to ensure continuation. Today a new generation of diets enable culture densities of 2000 rotifers per mill to be achieved over a 4 day cycle. These densities however require continuous supplies of O2 and algal requirement in mass cultures is unnecessary Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Rotifer Production M: Masters A: Culture (2-6 m3) B: Inoculum (500 R/ml) C: Enrichment (500-1000 R/ml) Larval Tanks M M2 A 30% 70% B C Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Culture Selco 3000 strategy Live food aquaculture training course www.aquatrain.org

Traditional rotifer batch culture Live food aquaculture training course www.aquatrain.org

High density rotifer production system Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Rotifer harvesting Rotifers should be harvested either from culture or from enrichment in a manner to ensure that they are well rinsed of metabolites, detritus and ciliates prior to their introduction to the larval rearing tank. This should be done in as gentle a manner as possible to avoid rotifer loss or mortality. Generally this is done in a manual way but this automated system seems to be effective and is labour saving. Live food aquaculture training course www.aquatrain.org

Harvesting of rotifers Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Transfer of rotifers Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Recent work in Belgium have taken high density culture one step further. Here recirculation systems and protein skimmers, in association with novel filters enable rotifer cultures to reach and be maintained at densities over 5000 per ml for prolonged periods of time. This one M3 system can produce 2 billion rots per day for a production unit. Savings such as these are beginning to play a significant role in the financial viability of the maturing bass and bream industry. Recirculated ultra-high density rotifer culture ~5000 rotifers + /ml Live food aquaculture training course www.aquatrain.org

Live food aquaculture training course Commercially available rotifer and artemia cultivation and enrichment products A number of commercially available cultivation and emulsion type enrichment diets are available together with products that for Artemia are capable of altering the microbiological characteristics of the hatching and enrichment environments This development both provides the farmer with custom nutritional packages and helps to deduce the possibility of disease that may be introduced through the live food chain. Live food aquaculture training course www.aquatrain.org

Fatty acid enrichment levels in Rotifers I shall not dwell upon the specifics of enrichment levels of live food organisms as it is complex and lengthy. However this table clearly shows that while algae enrichment alone does provide a variety of essential fatty acids and the profile of enrichment is affected by the species used the levels of enrichment of critical fatty acids obtained are inferior to those obtained by the use of commercial enrichment diets shown earlier Consequently irrespectively of the production system employed bream and bass hatcheries routinely enrich rotifers with commercial preparations to ensure optimal nutritional conditions for the larvae. Live food aquaculture training course www.aquatrain.org