Microalgae larvae

Larvae of the scallop Placopecten magellanicus actively selected monofilament substrates with dense coatings of bacteria, microalgae, and detritus.180 However, there was also significant settlement on noncoated monofilaments in these experiments, suggesting that preference does not imply a necessary inductive process by biofilm organisms for the scallop larvae to settle and... 

Rearing of the larvae is then managed in specifically designed tanks, often necessitating provision of specific larval diets that include both live feeds (microalgae, rotifers, and Artemia) and manufactured feeds. For most of the crustaceans,... 

Key words aquaculture feeds, hatchery, larvae, microalgae, live feeds, photobioreactor. 

Microalgae, the microscopic plants present in oceans and waterways, are exploited as an indispensible food source for the commercial production of many aquaculture species. Within the hatchery environment, they are directly eaten by all growth stages of bivalves (broodstock, larvae, juveniles), post-set abalone, the larval stages of some crustacean species, and the very early developmental stages of some fish species. Microalgae are also used as feed to culture zooplankton (e.g. Anemia, rotifers, copepods) that are used as food for larval and juvenile stages of many fish and crustacean species. 

Effects of different dietary microalgae on survival, growth, settlement and fatty acid composition of blue mussel (Mytilus galloprovincialis) larvae. Aquaculture, 309,115-124. 

PONIS E, PROBERT I, VERON B, MATHiEU M and ROBERT R (2006) New microalgae for the Pacific oyster Crassostrea gigas larvae. Aquaculture, 253, 618-627. 

ROCHA R J, RIBEIRO L, COSTA R and DiNis M T (2008) Does the presence of microalgae influence flsh larvae prey capture Aquaculture Research, 39, 362-369. 

Thanks to this last characteristic, rotifers can be cultured on many feed sources (e.g. microalgae or yeast cells) and, even more important, their nutritional composition can be adjusted in a relatively short time (called enrichment) to better suit the nutritional requirements of the predator (e.g. fish or shrimp larvae). In the culture of fresh water rotifers, B. calyciflorus, pH is important due to the ammonia-ammonium equilibrium. 

Baker s yeast is also a common feed. However, yeast contains less highly unsaturated fatty acids (HUFA), which results in rotifers with inferior nutritional quahty for the larvae compared to microalgae fed rotifers (Con-geicao et /., 2010). This is especially important for marine larvae as marine fish are not able to synthesize eicosapentaenoic acid (EPA) and docosa-hexaenoic acid DHA themselves from linolenic acid (for a review see Tocher, 2010). The nutritional composition of the rotifers can be adjusted through enrichment (i.e. inclusion of specific nutrients/chemicals essential to the larvae). There are many formulated feeds on the market that are... 

Although bacteria present in rotifer cultures can provide vitamin B (Yu et al, 1989) and microalgae such as Chlorella sp. and I. galbana provide vitamin C (Merchie et al, 1995), extra enrichment of thiamine (as thiamine HCl) and vitamin E (as DL-alpha-tocopherol) led to an increased concentration in the rotifers after four days. On the other hand, addition of vitamin A (as retinyl palmitate) in the diet did not lead to a significant increase in vitamin A content (Srivastava et al, 2011). As copepods and their naupUi are the natural food for many marine larvae, rotifers are also enriched in iodine in order to obtain iodine levels similar to those of copepods (Srivastava et al, 2006). 

NICOLAS J L, ROBIC E and ANSQUER D (1989) Bacterial flora associated with a trophic chain consisting of microalgae, rotifers and turbot larvae Influence of bacteria on larval survival. Aquaculture 83 237-248. 

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