Aquaculture International 11: 163–182, 2003. © 2003 Kluwer Academic Publishers. Printed in the Netherlands. Artemia prey size and mode of presentation: Effects on the survival and growth of phyllosoma larvae of southern rock lobster (Jasus edwardsii) ARTHUR J. RITAR 1∗ , GREG G. SMITH 1 , GRAEME A. DUNSTAN 2 , MALCOLM R. BROWN 2 and PIERS R. HART 1 1 Marine Research Laboratories, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Nubeena Crescent, Taroona, Tasmania 7053, Australia; 2 CSIRO Marine Research, GPO Box 1538 Hobart, Tasmania 7001, Australia; ∗ Author for correspondence (fax: +61-362278035; e-mail: Arthur.Ritar@utas.edu.au) Received 2 November 2001; accepted 29 October 2002 Abstract. Performance of phyllosoma of the southern rock lobster (Jasus edwardsii) was examined after feeding Artemia-based diets. Survival and growth of newly-hatched larvae cultured to Stage III were lower (p < 0.05) when fed 0.8 mm Artemia than 1.5 mm or 2.5 mm Artemia alone or 1.5 mm Artemia in combination with pieces of mussel (Mytilus edulis planu- latus) gonad. This could not be attributed to deficiencies in the composition of fatty acids but appeared to be due to the inability of larvae to capture sufficient appropriate-sized, enriched Artemia for their nutritional requirements. There was an indication that survival and growth were higher between Stages III and V when fed 2.5 mm Artemia than 1.5 mm Artemia alone or in combination with mussel pieces. However, Stage VI larvae grew to a similar size at Stage VIII when fed 1.5 mm or 2.5 mm Artemia. Unexpectedly, larvae fed the combination of 1.5 mm Artemia plus mussel supplement had lower survival than found previously, and gener- ally lower than when fed ≥ 1.5 mm Artemia alone. This was despite an apparent nutritional profile (lipid content and fatty acid composition) of mussel more akin to that of newly-hatched phyllosoma than enriched Artemia. On the other hand, survival and growth to Stage VIII were higher when larvae were fed alginate pellets containing Artemia than when fed 1.5 mm or 2.5 mm Artemia alone. Key words: Alginate, Artemia, Ascorbic acid, Jasus edwardsii, Larval rearing, Phyllosoma, Polyunsaturated fatty acid Introduction The naturally free-swimming phyllosoma of southern rock lobsters (Jasus edwardsii) feed on a range of zooplankton (Dexter 1972) and fish larvae (Kittaka 1999). The appendages, mouthparts and digestive system of phyl- losoma of several lobster species appear to be well-suited for the capture and consumption of soft-bodied organisms (Macmillan et al. 1997; Mikami and