7. CHEMICAL COMPOSITION
21 1
Tables XI-XI11 must be accepted with reservation until further
analyses are available.
The general characteristics of the lipids of Euphausia superba,
E . paci$ca, and Thysanoessa longipes, are shown in Table XIV. Saiki
et al. (1959) found 4.3% of unsaponifiable matter in the lipids of
Euphausia superba and 16.8% in the lipids of a mixed sample of
E. paciJica, Thysanozssa bongipes, and T . inermis and Ackman and
Eaton (1967) recorded 4.9% in the lipids of Meganyctiphanes norvegica.
The iodine value (IV) of the mixed fatty acids of Euphausia superba
was 140.8 and that of the mixed sample of three species 157.9 ; Ackman
and Eaton (1967) found an iodine value of 138 for the fatty acid esters
of Meganyctiphanes norvegica. Klem (1932, 1935) found an iodine value
of 160 for the oil of Euphausia superba and values of 163.5 and 167.5
for the fatty acids of E . superba and Meganyctiphanes norvegica
respectively. The few available detailed analyses of the fatty acid
composition of the lipids of euphausiids are presented in Tables XV and
XVI. I n addition to these analyses, Tsuyuki et al. (1964a) estimated
the component fatty acids of the acetone soluble lipid of Euphausia
superba as : saturated fatty acids, 31.78y0 (myristic 5.48y0, palmitic
11-41%, stearic 10.19%) arachidic 4.15y0, and behenic 0.19yo) ;
unsaturated fatty acids; 68.22% [C14 acids (--2.OH) 0.36%, C16 acids
(-2-3H) 14.5y0, Cl8 acids ( - 3 3 H ) 24.97%) C20 acids (-6.2H)
20.38%) and C22 acids ( - 5 4 H ) 8.01%]. The relative quantities of
myristic, palmitic, and stearic acids vary but more data are required
before firm conclusions can be drawn. The same applies to comparisons
of the relative amounts of higher unsaturated fatty acids present in the
different species. Kelly et al. (1959) found that crustaceans lost much
of their polyunsaturated acids when fed on a fat-free diet but replaced
them when the diet was changed. There is evidence in their data that
the shrimp was able to synthesize more highly unsaturated acids than
the crabs and non-crustacean organisms tested. More work, however,
in this field is required.
The discussion on lipids of Euphausiacea refers to " depot " fats,
that is stored fats and no direct information is available on non-depot
lipids. Likewise, unsaponifiable matter is present but sterols have not
been studied, except by Fagerlund (1962) who states that cholesterol
is the only major sterol in Euphausia pacijka, an observation
since confirmed in E . superba by Vinogradova (1967) who also found
0.03% wet wt to be provitamin D. Work is required on many
other related substances in these animals.
Tsuyuki et al. (1964b) have examined the phospholipids of Euphausia
superba. Myristic, palmitic, stearic, arachidic, behenic, palmitoleic,
21 1
Tables XI-XI11 must be accepted with reservation until further
analyses are available.
The general characteristics of the lipids of Euphausia superba,
E . paci$ca, and Thysanoessa longipes, are shown in Table XIV. Saiki
et al. (1959) found 4.3% of unsaponifiable matter in the lipids of
Euphausia superba and 16.8% in the lipids of a mixed sample of
E. paciJica, Thysanozssa bongipes, and T . inermis and Ackman and
Eaton (1967) recorded 4.9% in the lipids of Meganyctiphanes norvegica.
The iodine value (IV) of the mixed fatty acids of Euphausia superba
was 140.8 and that of the mixed sample of three species 157.9 ; Ackman
and Eaton (1967) found an iodine value of 138 for the fatty acid esters
of Meganyctiphanes norvegica. Klem (1932, 1935) found an iodine value
of 160 for the oil of Euphausia superba and values of 163.5 and 167.5
for the fatty acids of E . superba and Meganyctiphanes norvegica
respectively. The few available detailed analyses of the fatty acid
composition of the lipids of euphausiids are presented in Tables XV and
XVI. I n addition to these analyses, Tsuyuki et al. (1964a) estimated
the component fatty acids of the acetone soluble lipid of Euphausia
superba as : saturated fatty acids, 31.78y0 (myristic 5.48y0, palmitic
11-41%, stearic 10.19%) arachidic 4.15y0, and behenic 0.19yo) ;
unsaturated fatty acids; 68.22% [C14 acids (--2.OH) 0.36%, C16 acids
(-2-3H) 14.5y0, Cl8 acids ( - 3 3 H ) 24.97%) C20 acids (-6.2H)
20.38%) and C22 acids ( - 5 4 H ) 8.01%]. The relative quantities of
myristic, palmitic, and stearic acids vary but more data are required
before firm conclusions can be drawn. The same applies to comparisons
of the relative amounts of higher unsaturated fatty acids present in the
different species. Kelly et al. (1959) found that crustaceans lost much
of their polyunsaturated acids when fed on a fat-free diet but replaced
them when the diet was changed. There is evidence in their data that
the shrimp was able to synthesize more highly unsaturated acids than
the crabs and non-crustacean organisms tested. More work, however,
in this field is required.
The discussion on lipids of Euphausiacea refers to " depot " fats,
that is stored fats and no direct information is available on non-depot
lipids. Likewise, unsaponifiable matter is present but sterols have not
been studied, except by Fagerlund (1962) who states that cholesterol
is the only major sterol in Euphausia pacijka, an observation
since confirmed in E . superba by Vinogradova (1967) who also found
0.03% wet wt to be provitamin D. Work is required on many
other related substances in these animals.
Tsuyuki et al. (1964b) have examined the phospholipids of Euphausia
superba. Myristic, palmitic, stearic, arachidic, behenic, palmitoleic,