Nutrition in hatchery production. Joe Brown & Chris Parrish Ocean Sciences Centre, Memorial University of Newfoundland

Transcription

1 Nutrition in hatchery production Joe Brown & Chris Parrish Ocean Sciences Centre, Memorial University of Newfoundland

2 Collaborators & students Dr H. Park Dr V. Puvanendran Alexandre Garcia Anne Kellett Lynn Lush Kelly O Brien-MacDonald Joy Wade

3 Outline of presentation Will present a series of three studies: results of two are in press third, analysis ongoing all focus on performance of cod larvae and rotifer enrichment

4 Introduction primary source of energy structural components of cell membranes source of essential fatty acids and bioactive molecules

5 Background Important starter feed used in larviculture. 40 % of the total aquaculture demand for feeds for early stages Dhert et al. (2001) Sorgeloos et al. (2001)

6 Background Brown et al., 2003 Atlantic cod early feeding protocol at 11 o C weaning dry feed rotifers Artemia nauplii age (days) picture:

7 Background Bell et al. (2003) Sargent et al. (1999) copepods rotifers Artemia cod larvae DHA % 0.1 % 0.0 % 30.2 % EPA % 0.2 % 5.3 % 15.0 % AA % trace 1.2 % 1.8 % % of total fatty acids

8 Materials and methods first feeding tank live-food enrichment tank

9 Integrating growth, behaviour and digestive enzyme activity in larval Atlantic cod (Gadus morhua): response to rotifer lipids. O Brien-MacDonald, Brown, Parrish ICES J Mar Sci in press Investigate the variability in digestive development in response to the quantity of lipid in the rotifer enrichment. Survival, growth, behaviour and digestive enzyme data from hatching to metamorphosis (0-450 dd [degree-days]) were measured. Four treatments were used in triplicate: high lipid rotifer enrichment, low lipid rotifer enrichment, green water and unfed.

10 Rotifer enrichments: Brachionus plicatilis LL (T. iso) ) rotifers HL (AlgaMac( AlgaMac) ) rotifers 7.1% DW lipid: 11.2% DW lipid: 5.1% TAG 20.6% TAG 21.4% PL 21.6% PL Lipid (μg/mg( dw): DHA: EPA: DHA:EPA

11 Myotome height and standard length of cod larvae Myotome height (mm) High lipid rotifers Low lipid rotifers Greened Unfed Standard length (mm) Degree days Degree days O Brien-MacDonald, Brown, Parrish ICES J Mar Sci in press

12 Swimming activity and attack rate (captures+misses) Swimming Activity (% time) High lipid rotifers Low lipid rotifers Greened Unfed Attack rate (prey /min) High lipid rotifer Low lipid rotifer Degree Days Degree Days O Brien-MacDonald et al.

13 General lipase activity and alkaline phosphatase activity Lipase Activity (U/mg protein) High lipid rotifers Low lipid rotifers Greened Unfed Alkaline Phosphatase Activity (U/mg protein) O Brien-MacDonald et al. Degree Days Degree Days

14 O Brien-MacDonald, Brown, Parrish: Summary Swimming activity and attacks (captures + misses) on prey were higher in the high lipid group by 100 dd and increased over time. No differences between digestive enzyme activity for the unfed and greened treatments. Low lipid larvae had lower activity levels by dd for all enzymes. Larvae in the unfed and green water treatments did not survive past 100 dd. Suggests that a higher quantity of lipid in the rotifer enrichment promotes higher growth and survival and provides more energy to allow larvae to capture more prey.

15 Effect of enriched rotifers on growth, survival and composition of Atlantic cod (Gadus morhua) larvae. Park, Puvanendran, Kellett, Parrish, Brown ICES J Mar Sci in press Used three different commercial rotifer enrichment diets and a mixture of one diet with Chlorella. Cod larvae were fed rotifers with different proportions of docosahexaenoic acid (DHA) and ratios to eicosapentaenoic acid (EPA).

16 Survival of Atlantic cod larvae fed four differently enriched rotifers % DHA High 23 Medium Low 14 Survival (%) 20 DHA/EPA High 9-10 Medium 8 Low High % / high ratio Medium % / high ratio Low % / low ratio Medium % / Medium ratio Park et al. ICES J Mar Sci in press Treatments

17 Growth of Atlantic cod larvae fed the differently enriched rotifers Standard Length (mm) a) High % / high ratio Medium % / high ratio Low % / low ratio Medium % / medium ratio a ab b ab a bc c ab a a ab b a a b b a ab c b 4 Dry weight (mg) b) % DHA High 23 Medium Low 14 DHA/EPA High 9-10 Medium 8 Low 4 ac b c ab a b a a a a b b aac bc b a ab ab b Park et al. ICES J Mar Sci in press Age (days post-hatch)

18 Lipid content of Atlantic cod larvae fed differently enriched rotifers Total lipid (DW)(mg.g -1 ) a) High % / high ratio Medium % / high ratio Low % / low ratio Medium % / medium ratio 80 b) 75 PL (%) TAG (%) Park et al. ICES J Mar Sci c) Age (Days post-hatch)

19 DHA:EPA ratio Fatty acid content of Atlantic cod larvae fed differently enriched rotifers ARA (%) a) a b c d EPA (%) b) High % / high ratio Medium % / high ratio Low % / low ratio Medium % / medium ratio a b c d c) a a d) a DHA (%) 30 b 28 c Park et al. Age (Day post-hatch) Age (Days post-hatch) b c d

20 Park, Puvanendran, Kellett, Parrish, Brown: Summary Results showed a positive effect of rotifer DHA proportions on growth and survival of cod larvae. Demonstrated that Atlantic cod larvae require a high ratio of dietary DHA to EPA.

21 Final study (A. Garcia, PhD student) Objective To evaluate the effects of different commercially available enrichments on the early growth, survival, and lipid composition of Atlantic cod larvae

22 Materials and methods

23 Materials and methods Lipid Classes (mg/g) Algamac 2000 Advantage Pavlova sp. DHA Selco Total lipids ± 4.82 a ± ab ± 3.23 b ± c Triacylglycerol ± 5.28 a ± 4.56 ab ± 0.94 b ± c Phospholipids 3.92 ± 0.15 a 4.70 ± 0.73 a ± 2.21 a ± 5.60 b

24 Materials and methods tanks: 3,000 L, cylindrical, flat bottom 2 replicates/treatment stocking density: 50 larvae L-1 prey density: rotifers - 4,000 rotifers L -1 Artemia - 3 to 12 million tank -1 day -1 feedings: between 9:00-10:00 am & between 4:00-5:00 pm temperature: ~ 11 o C

25 Materials and methods growth dry weight, SGR survival semi-quantitative (0-5) lipid composition rotifers & Artemia/ before & after enrichment fish larvae bi-weekly enrichments algae paste

26 Results Lipid classes in rotifers (mg/g) Unenriched rotifers Advantage-enriched rotifers Algamac-enriched rotifers Pavlova enriched rotifers Algamac + Pavlova enriched rotifers Total lipids TAG FFA ST PL

27 Survival picture: Advantage Algamac 2000 Algamac Pavlova sp. Algamac DC DHA Selco Days post hatch

28 Overall growth picture: dry weight (mg) O day = Artemia degree days Advantage Algamac 2000 Overall SGR 9.32 %.d %.d %.d %.d -1 Algamac Pavlova sp. Algamac DC DHA Selco Treatment ± 1.13mg a Treatment ±0.87 mg ab Treatment ± 0.32 mg bc Treatment ± 0.20mg c

29 Lipid classes in cod larvae (37 dph) Advantage Algamac 2000 Algamac Pavlova sp. (mg/g) Total lipids TAG FFA ST PL

30 PUFA % Total Fatty Acids Initial Pavlova and Algamac Advantage Algamac Selco and Algamac a a b a ab b ab Days

31 Take home: High lipids, DHA & DHA:EPA = High growth & survival Acknowledgments Danny Boyce and the Aquaculture Research Development Facility (ARDF) staff for their valuable help with live-food production and larval rearing. AquaNet Canada s Network of Centres of Excellence for aquaculture research. Going Global Science and Technology Fund, International Trade Canada