288
R.G. Ackman
freshwater crayfish Procambarus clarkii and rainbow trout Oncorhynchus mykiss
showed no great difference, so that salinity was not established as important in
respect to the ether lipids. Smolting of salmon is a possible exception to this
general view, but the gills adapt in a short time (Takeuchi et aI., 1990). In fact, the
fish fatty acid pattern for salmon may shift from fresh water to marine on an
anticipatory basis (Sheridan, 1994). The reversal of this adaption to allow the
salmon to re-enter rivers for spawning suggests that major changes in lipid classes
are unlikely. There is little doubt that phospholipids of fish gills are extremely
important in salt transport (EI Babili et a!., 1996; Hansen et a!., 1992; Takeuchi et
a!., 1989), and this applies to crustacea as well (Chapelle, 1986).
A unique report of analysis of these ether lipids is available for the freshwater
sponge Eunapiusfragilis of Lake Michigan; the method applied was 31p nuclear
magnetic resonance (Early et a!., 1996). Eighteen different phospholipids, including ether lipids, were used to differentiate three habitats on the basis of "indexes"
of associated phospholipid types. The differences found in phospholipid profiles
(mole %) were relatively minor, but these immobile animals could be differentiated as to origin by powerful statistics. For those more familiar with conventional
technology such as HPLC, an extensive thesis has been published in English
(Takahashi, 1985) and is applied to polar lipids with comprehensive tabulations of
results for western Pacific fish and shellfish.
11.2.7. Prostanoids
The adjustment of phospholipid ratios and fatty acid compositions may be an
important response to stress. The model most often tested in fish is thermal
adaption (Fodor et a!., 1995). In all this elegant work on lipids, the highly sophisticated systems for producing eicosanoids (i.e., prostaglandins) from polyunsaturated fatty acids are often overlooked. Research with freshwater fish indicates that
the eicosanoids are produced in all organs and tissues (Henderson and Tocher,
1987). Different tissues of marine fish such as turbot (Scophthalmus maximus) are
also very active in this respect (Tocher et a!., 1996; Henderson et aI., 1985).
Another example is the effect of dietary fatty acids on eicosanoid production and
immune function in Atlantic salmon (Bell et aI., 1996, 1993) or rainbow trout
(Kiron et a!., 1995). For immobile invertebrates such as bivalves (Deridovich and
Reunova, 1993), for colonial worms (Toonen and Pawlik, 1996), and even for sea
urchins (Kitamura et ai., 1993), following metamorphosis, there is evidence that
the settling processes are governed by chemical signals based on similar biochemical reactions (Ackman and Kean-Howie, 1995). Prostaglandin activity may
also influence production of natural aromas or flavor elements from fatty acids in
freshwater or marine fish or mollusks (Lindsay, 1990; Josephson et aI., 1984).
The terrestrial world is dominated by m6 polyunsaturated fatty acids, the
aquatic world largely by (03 polyunsaturated fatty acids. These compete for
eicosanoid production (Lands, 1986), but it appears that the (03-based group may
be older and more fundamental, and the (06 group a terrestrial adaption to capitalize on the more plentiful 18:2(06 fatty acid of land plants. The colonization of
R.G. Ackman
freshwater crayfish Procambarus clarkii and rainbow trout Oncorhynchus mykiss
showed no great difference, so that salinity was not established as important in
respect to the ether lipids. Smolting of salmon is a possible exception to this
general view, but the gills adapt in a short time (Takeuchi et aI., 1990). In fact, the
fish fatty acid pattern for salmon may shift from fresh water to marine on an
anticipatory basis (Sheridan, 1994). The reversal of this adaption to allow the
salmon to re-enter rivers for spawning suggests that major changes in lipid classes
are unlikely. There is little doubt that phospholipids of fish gills are extremely
important in salt transport (EI Babili et a!., 1996; Hansen et a!., 1992; Takeuchi et
a!., 1989), and this applies to crustacea as well (Chapelle, 1986).
A unique report of analysis of these ether lipids is available for the freshwater
sponge Eunapiusfragilis of Lake Michigan; the method applied was 31p nuclear
magnetic resonance (Early et a!., 1996). Eighteen different phospholipids, including ether lipids, were used to differentiate three habitats on the basis of "indexes"
of associated phospholipid types. The differences found in phospholipid profiles
(mole %) were relatively minor, but these immobile animals could be differentiated as to origin by powerful statistics. For those more familiar with conventional
technology such as HPLC, an extensive thesis has been published in English
(Takahashi, 1985) and is applied to polar lipids with comprehensive tabulations of
results for western Pacific fish and shellfish.
11.2.7. Prostanoids
The adjustment of phospholipid ratios and fatty acid compositions may be an
important response to stress. The model most often tested in fish is thermal
adaption (Fodor et a!., 1995). In all this elegant work on lipids, the highly sophisticated systems for producing eicosanoids (i.e., prostaglandins) from polyunsaturated fatty acids are often overlooked. Research with freshwater fish indicates that
the eicosanoids are produced in all organs and tissues (Henderson and Tocher,
1987). Different tissues of marine fish such as turbot (Scophthalmus maximus) are
also very active in this respect (Tocher et a!., 1996; Henderson et aI., 1985).
Another example is the effect of dietary fatty acids on eicosanoid production and
immune function in Atlantic salmon (Bell et aI., 1996, 1993) or rainbow trout
(Kiron et a!., 1995). For immobile invertebrates such as bivalves (Deridovich and
Reunova, 1993), for colonial worms (Toonen and Pawlik, 1996), and even for sea
urchins (Kitamura et ai., 1993), following metamorphosis, there is evidence that
the settling processes are governed by chemical signals based on similar biochemical reactions (Ackman and Kean-Howie, 1995). Prostaglandin activity may
also influence production of natural aromas or flavor elements from fatty acids in
freshwater or marine fish or mollusks (Lindsay, 1990; Josephson et aI., 1984).
The terrestrial world is dominated by m6 polyunsaturated fatty acids, the
aquatic world largely by (03 polyunsaturated fatty acids. These compete for
eicosanoid production (Lands, 1986), but it appears that the (03-based group may
be older and more fundamental, and the (06 group a terrestrial adaption to capitalize on the more plentiful 18:2(06 fatty acid of land plants. The colonization of