Nutritional parameters

Biochemical determinants of larval competency were examined primarily from the perspective of manipulating broodstock lipid and AA dietary regimes

(Chapters 6 and 7). It was noted that the lipid and fatty acid profiles of broodstock ovary and tail muscle were stable over time despite the provision of an unusual dietary mix of EFA (Chapter 6). This stability extended to the phyllosoma with minimal differences between the fatty acid profiles of animals from two widely differing diets, suggesting that larval profiles are maintained under situations of extreme nutritional duress, as sometimes reported in wild populations (Jernakoff et al. 1993; Barkai et al. 1996; Cox et al. 1997). There was no direct link between fatty acid profiles and survival of larvae in culture or activity tests. Therefore, the stability of both broodstock and phyllosoma lipid and fatty acid profiles and the ability of animals to sequester their requirements from meager supplies should largely negate concerns about the need to supplement broodstock dietary fatty acids to maintain larval competency. The other organ examined was the digestive gland, which demonstrated a large storage capacity for dietary lipids and fatty acids, with no evidence for direct sequestering of these stores during ovarian maturation. Lipid catabolism appeared to occur during periods of inadequate nutrition, which is useful for wild animals experiencing dietary deficiencies. The digestive gland fatty acid profile was malleable and assumed the fatty acid profile of the diet, which may be a potential correlate for identifying those feed sources associated with improved larval competency in wild animals.

The concentration of dietary AA required to saturate broodstock ovaries in J. edwardsii was relatively low and concomitant with low ovarian saturation

concentrations compared to some other crustaceans (Cavalli, 2000; Wouters et al., 2001). Further, there were minimal benefits to AA supplementation above and beyond that supplied by the basal mix of fresh and compound penaeid diet. Even though AA supplementation prevented the depletion of muscle AA this did not confer any benefit to these animals, with no significant differences noted across the range of broodstock and phyllosoma parameters measured. These results contrast with those in other studies where dietary AA supplementation of

quality (Kontara et al., 1997; Moreau et al., 1998). A combination of fresh and compound diet, as supplied during this study, should provide adequate

concentrations of AA to meet the needs of J. edwardsii broodstock and embryo during development to larvae.

In contrast, there were a number of tangible benefits obtained with AA dietary supplementation to phyllosoma, including increases to phyllosoma growth and most notably survival. This is the first time that supplementation has shown clear improvements in these parameters beyond that of the standard Artemia diet. Previous nutritional studies with J. edwardsii phyllosoma have concentrated on manipulating lipid and fatty acid nutritional profiles without any obvious benefits to growth and survival (A. Ritar and P. Hart pers. comm.). It was also noted during this study that phyllosoma supplied with algalenriched Artemia were also

conferred with considerable improvements to growth and survival compared with unsupplemented Artemia. The reasons for this are unknown but are likely to be due to the provision of a suite of nutritional factors that are missing or lacking in existing larval foods. This may be an indication that a range of natural marine dietary products may be of benefit to furthering larval culture in this species. An important proposition was confirmed during this study, namely that the larval tissue concentration of AA reflects an animals survival potential (Dabrowski, 1992) i.e., the ability to increase the amount of AA in early stage phyllosoma was correlated with an improvement to survival. However, this proposition did not extend to broodstock or developing embryo (Chapter 7) and may decrease with subsequent stages of phyllosoma development, but this is a future area of research.

9.2. Summary

This study developed a robust technique to assess larval competency at hatch providing the tools to circumvent problems associated with larval competency at the commencement of culture. A capacity to extend the analysis of competency to later developmental stages was also demonstrated. The boundaries of Artemia live feed protocols and regimes were extended providing a better understanding of the requirements and capacity of this important aquaculture feed source. A range of

environmental (temperature manipulation), physiological (broodstock size, larval size) and nutritional (AA) factors were identified which will assist in the selection of larvae of optimal competency. To further studies of phyllosoma culture a focus upon ascertaining the physiological causes of mortality will be required, the prime suspect being bacterial contamination, influenced by factors such as feed

composition and delivery, water quality and tank configuration. These issues are problematic in this species due to the prolonged larval duration and the effect that they may have upon even competent larvae if exposed for sufficient duration.

9.3. References

Abi-ayad, S-M. A-E., Melard, C., Kestemont, P., 1995. Effect of n-3 fatty acid in European perch (Perca fluviatilis) broodstock diet on survival of larvae after stress tests. Larvi’95 – Fish and Shellfish Larviculture Symposium. European Aquaculture Society, Special publication No. 24 Gent pp. 12-15.

Abrunhosa, F.A., Kittaka, J., 1997. Functional morphology of mouthparts and foregut of the last zoea, glaucothoe and first juvenile of the king crabs Paralithodescomtschaticus, P. brevipes

and P. platypus. Fish. Sci. 63, 923-930.

Annala, J.H., McKoy, J.L., Booth, J.D., Pike, R.B., 1980. Size at the onset of sexual maturity in female Jasus edwardsii (Decapoda: Palinuridae) in New Zealand. N.Z. J. Mar. Freshwat. Res. 14, 217-227.

Barkai, A., Davis, C.L., Tugwell, S., 1996. Prey selection by the South African cape rock lobster

Jasus lalandii: Ecological and physiological approaches. Bull. Mar. Sci. 58, 1-8.

Berry, P.F., 1971. The biology of the spiny lobster Panulirus homarus (Linnaeus) off the east coast of Southern Africa, Report 28. Oceanographic Research Institute, Durban 75p.

Booth, J., 1996. Phyllosoma reared to settlement. The Lobster Newsletter 8, 1 and 12.

Cahu, C.L., Cuzon, G., Quazuguel, P., 1995. Effect of highly unsaturated fatty acids, α-tocopherol and ascorbic acid in broodstock diet on egg composition and development of Penaeus indicus. Comp. Biochem. Physiol. 112A, 417-424.

Cavalli, R.O., Lavens, P., Sorgeloos, P., 1999. Performance of Macrobrachium rosenbergii

broodstock fed diets with different fatty acid composition. Aquaculture 179, 387-402. Cavalli, R.O., 2000. Broodstock nutrition and offsping quality of the freshwater prawn

Macrobrachium rosenbergii (de Man). PhD. Dissertation. Faculty of agricultural and applied biological sciences, Gent University, Gent, Belguim.

Cox, C., Hunt, J.H., Lyons, W.G., Davis, G.E., 1997. Nocturnal foraging of the Caribbean spiny lobster (Panulirus argus) on offshore reefs of Florida, USA. Mar. Freshwater Res. 48, 671-679. Crain, J.A., 1999. Functional morphology of prey ingestion by Placetraom wosnessenskii

Schalfeew xoeae (Crustacea: Anomura: Lithdidae). Biol. Bull. Mar. Biol. Lab. Woods Hole. 197, 207-218.

Dhert, Ph., Lavens, P., Sorgeloos, P., 1992a. Stress evaluation: A tool for quality control of hatchery-produced shrimp and fish fry. Aquacult. Sci. Eur. 17, 6-10.

Evjemo, J., Coutteau, P., Olsen, Y., Sorgeloos, P., 1997. The stability of docosahexaenoic acid in two Artemia species following enrichment and subsequent starvation. Aquaculture 155, 135-48. Evjemo, J.O., Danielsen, T.L., Olsen, Y., 2001. Losses of lipid, protein and n-3 fatty acids in

enriched Artemia fransicana starved at different temperatures. Aquaculture 193, 65-80. Gordon, I., 1960. On the genus Justitia holthuis (Decapoda, Palinuridae), with a note on allometric

growth in Panulirus ornatus (Fabricius). Crustaceana 1, 295-306.

Jernakoff, P., Phillips, B.F., Fitzpatrick, J.J., 1993. The diet of post-puerulus western rock lobster,

Panulirus cygnus George, at Seven Mile Beach, Western Australia. Aust. J. Mar. Freshwater Res. 44, 649-655.

Johnston, D.J., Ritar, A., 2001. Mouthpart and foregut ontogeny in phyllosoma larvae of the spiny lobster Jasus edwardsii (Decapoda; Palinuridae). Mar. Freshwater Res. 52, 1375-1386.

Kanazawa, A., 1997. Effects of docosahexaenoic acid and phospholipids on stress tolerance of fish. Aquaculture 155, 129-134.

Kittaka, J., Iwai, M., Yoshimura, M., 1988. Culture of a hybrid of spiny lobster genus Jasus from egg to puerulus stage. Nippon Suisan Gakk. 54, 413-417.

Kontara, I.K., Merchie, G., Lavens, P., Robles, R., Nelis, H., De Leenheer, A., Sorgeloos, P., 1997. Improved production of postlarval white shrimp through supplementation of L-ascorbyl-2- polyphosphate in their diet. Aquacult. Int. 5, 127-136.

Kubo, I., 1938. Notes on the sexual dimorphism of the spiny lobster, Panulirus japonicus (v. Siebold). J. Imp. Fish. Inst. 33, 101-107.

Lim, L.C., Dhert, P., Chew, W.Y., Dermaux, V., Nelis, H., Sorgeloos, P., 2002. Enhancement of stress resistance of the guppy Poecelia reticulata through feeding with vitamin C supplement. J. World Aquaculture Soc. 33, 32-40.

Merchie, G., Lavens, P., Dhert, Ph., García Ulloa Gómez, M., Nelis, H., De Leenheer, A., Sorgeloos, P., 1995a. Variation of ascorbic acid content in different live food organisms. Aquaculture 134, 325-337.

Merchie, G., Lavens, P., Dhert, Ph., Pector, R., Mai Soni, A.F., Abes, M., Nelis, H., Ollevier, F., De Leenheer, A., Sorgeloos, P., 1995b. Live food mediated vitamin C transfer to Dicentrarchus labrax and Clarias gariepinus. J. Appl. Ichthyol. 11, 336-341.

Merchie, G., Lavens, P., Radull, J., Nelis, H., De Leenheer, A., Sorgeloos, P. 1995c. Evaluation of vitamin C-enriched Artemia nauplii for larvae of the giant freshwater prawn. Aquacult. Int. 3, 355-363.

Merchie, G., Lavens, P., Sorgeloos, P., 1997. Optimization of dietary vitamin C in fish and crustacean larvae: a review. Aquaculture 155, 165-181.

Moreau, R., Cuzon, G., Gabaudan, J., 1998. Efficacy of silicone-coated ascorbic acid and ascorbyl- 2-polyphosphate to fast-growing tiger shrimp (Penaeus monodon). Aquacult. Nutr. 4, 23-29. Moss, G.A, Tong, L.J., Illingworth, J., 1999. Effects of light intensity and food density on the

growth and survival of early-stage phyllosoma larvae of the rock lobster Jasus edwardsii. Mar. Freshwater Res. 50, 129-134.

Narciso, L., Pousao-Ferreira, P., Passos, A., Luis, O., 1999. HUFA content and DHA/EPA improvements of Artemia sp. with commercial oils during different enrichments periods. Aquacult. Res. 30, 21-24.

Pollock, D.E., 1993. Recruitment overfishing and resilience in spiny lobster populations. ICES J. mar. Sci. 50, 9-14.

Pollock, D.E., 1997. Egg production and life-history strategies in some clawed and spiny lobster populations. Bull. Mar. Sci. 61, 97-109.

Rasowo, J., Devresse, B., Leger, P., Sorgeloos, P., 1995. Growth, survival, stress resistance and development rate of larval Macrobrachium rosenbergii (de Man) fed Artemia nauplii enriched with w3-highly unsaturated fatty acids. Kenya J. Sci. Technol. B. Biol. Sci. 11, 23-31.

Rees, J.F., Curé, K., Piyatiratitivorakul, S., Sorgeloos, P., Menasveta, P., 1994. Highly unsaturated fatty acid requirements of Penaeus monodon postlarvae: an experimental approach based on

Artemia enrichment. Aquaculture 122, 193-207.

Tackaert, W., Abelin, P., Leger, P., Sorgeloos, P., 1989. Stress resistance as a criterion to evaluate quality of postlarval shrimp reared under different feeding procedures. In: Proceed. III Simp. Brasileiro sobre cultivo de camaroa. Vol 1. MCR Aquacultura, Joao Pesoa, Brazil pp, 565. Tong, L. J., Moss, G. A., Paewai, M. M., Pickering, T. D., 1997. Effect of brine-shrimp numbers

on growth and survival of early-stage phyllosoma larvae of rock lobster Jasus edwardsii. Mar. Freshwater Res. 48, 935-940.

Watanabe, T., Kitajima, C., Fujita, S., 1983. Nutritional values of live organisms used in Japan for mass propagation of fish: a review. Aquaculture 34, 115-143.

Wouters, R., Molina, C., Lavens, P., Calderón, J., 2001. Lipid composition and vitamin content of wild female Litopenaeus vannamei in different stages of sexual maturation. Aquaculture 198, 307-323.