162
Y. Olsen
published at approximately the same time, and in the time that followed, it has
been confirmed that many cultured marine animals have high m3 requirements.
The above Japanese findings and the mass rearing techniques simultaneously
developed for B. plicatilis (Hirata, 1980) have been very important for the later
developments in marine larviculture and in mariculture in general. B. plicatilis is
used worldwide as a live feed for marine larvae, and considerable efforts have
been made worldwide during the past decade to improve and adapt the Japanese
methods to species with commercial potential. These studies have shown that
marine fish larvae, in particular those living in relatively cold water or with high
growth potential, have high and rather specific requirements for highly unsaturated m3 fatty acids (m3 HUFA). It has also become evident that all groups
of organisms, including crustaceans and shellfish, exhibit enhanced survival,
growth, and viability when their EFA requirements are met during the juvenile
stage. Aspects related to marine larval m3 HUFA requirements and the techniques
to manipulate lipids and fatty acid composition of zooplankton organisms used as
live feed have been dealt with in numerous of conferences during the past decade,
and m3 HUFA requirements are probably still the most frequent nutritional question brought up in larval nutrition studies.
The research on lipids and EFA in marine larvae and food zooplankton (mainly
in B. plicatilis and brine shrimp Artemia sp.) have provided a fundamental knowledge base that is useful in the field of food-quality research related to natural food
webs, including freshwater food webs. The existing knowledge is not always
directly applicable to freshwater systems, but many of the principal mechanisms
and conclusions, as well as the more applied perspectives, may be useful for
freshwater biologists.
The main goal here is to summarize knowledge on lipids and EFAs established
in mariculture that may have relevance also for freshwater food webs. The chapter
is not a literature review but a presentation of selected studies. I address and
speculate on interesting observations without directly critically evaluating findings and conclusions made by others.
8.2. Results and Discussion
8.2.i. Some important Lipids and Fatty Acids
Many textbooks as well as several chapters in this book (e.g., Arts, Cavaletto and
Gardner, Landrum and Fisher, Parrish, and Wainman et al.) describe the common
types of lipids normally found in freshwater organisms. I only briefly mention the
lipid and fatty acid groups that are important to understand the principal issues
treated.
8.2.1.1. Essential Fatty Acids
The fatty acids found in biological matter are grouped according to their chemical
or biological properties. From the perspective of animal nutrition, fatty acids may
Y. Olsen
published at approximately the same time, and in the time that followed, it has
been confirmed that many cultured marine animals have high m3 requirements.
The above Japanese findings and the mass rearing techniques simultaneously
developed for B. plicatilis (Hirata, 1980) have been very important for the later
developments in marine larviculture and in mariculture in general. B. plicatilis is
used worldwide as a live feed for marine larvae, and considerable efforts have
been made worldwide during the past decade to improve and adapt the Japanese
methods to species with commercial potential. These studies have shown that
marine fish larvae, in particular those living in relatively cold water or with high
growth potential, have high and rather specific requirements for highly unsaturated m3 fatty acids (m3 HUFA). It has also become evident that all groups
of organisms, including crustaceans and shellfish, exhibit enhanced survival,
growth, and viability when their EFA requirements are met during the juvenile
stage. Aspects related to marine larval m3 HUFA requirements and the techniques
to manipulate lipids and fatty acid composition of zooplankton organisms used as
live feed have been dealt with in numerous of conferences during the past decade,
and m3 HUFA requirements are probably still the most frequent nutritional question brought up in larval nutrition studies.
The research on lipids and EFA in marine larvae and food zooplankton (mainly
in B. plicatilis and brine shrimp Artemia sp.) have provided a fundamental knowledge base that is useful in the field of food-quality research related to natural food
webs, including freshwater food webs. The existing knowledge is not always
directly applicable to freshwater systems, but many of the principal mechanisms
and conclusions, as well as the more applied perspectives, may be useful for
freshwater biologists.
The main goal here is to summarize knowledge on lipids and EFAs established
in mariculture that may have relevance also for freshwater food webs. The chapter
is not a literature review but a presentation of selected studies. I address and
speculate on interesting observations without directly critically evaluating findings and conclusions made by others.
8.2. Results and Discussion
8.2.i. Some important Lipids and Fatty Acids
Many textbooks as well as several chapters in this book (e.g., Arts, Cavaletto and
Gardner, Landrum and Fisher, Parrish, and Wainman et al.) describe the common
types of lipids normally found in freshwater organisms. I only briefly mention the
lipid and fatty acid groups that are important to understand the principal issues
treated.
8.2.1.1. Essential Fatty Acids
The fatty acids found in biological matter are grouped according to their chemical
or biological properties. From the perspective of animal nutrition, fatty acids may